Zoom lens having high variable magnification

In a zoom lens having a high variable magnification, first and second lens groups and respectively having negative and positive focal lengths are sequentially arranged from an object side of the zoom lens to an image side thereof. A combined focal length of an entire lens system is charged by changing a distance between the first and second lens groups while the position of an image surface is constantly held. The zoom lens is constructed such that the second lens group is constructed by front and rear lens groups respectively having positive and negative focal lengths.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a compact zoom lens which has a high 
variable magnification and can be used as a photographing lens for a 35 mm 
lens shutter camera. 
2. Description of the Related Art 
A general zoom lens used for a 35 mm lens shutter camera is basically of a 
telephotographic type to reduce an entire length of the zoom lens. 
A simplest zoom lens of the telephotographic type is often constructed by a 
first lens group having a positive focal length and a second lens group 
having a negative focal length. 
However, when the zoom lens of this type is used to obtain a high variable 
magnification, an F-number of the zoom lens at a telescopic end thereof is 
extremely increased and a moving amount of the second lens group having a 
negative focal length is extremely increased when a zooming operation is 
performed from a wide angle end of the zoom lens to the telescopic end 
thereof. 
To solve these problems, for example, Japanese Patent Application Laying 
Open (KOKAI) No. 62-50718 and U.S. Pat. No. 4,828,372 show a lens 
structure constructed by a first lens group having a negative focal length 
and a second lens group having a positive lens group. This second lens 
group is constructed by a front lens group having a positive focal length 
and a rear lens group having a negative focal length. An entire length of 
the lens structure is reduced by such first and second lens groups. 
However, in the lens structure shown in Japanese Patent Application Laying 
Open (KOKAI) No. 62-50718, the distance between principal points of the 
front and rear lens groups constituting the second lens group is 
considerably short in comparison with the focal length of the front lens 
group. Therefore, refracting power of the front lens group in the second 
lens group is increased so that it is difficult to reduce an F-number of 
the lens structure and increase brightness of the lens structure. Further, 
a back focus of the lens structure is also increased so that the entire 
length of the lens structure cannot be necessarily reduced sufficiently. 
In the lens structure shown in the above U.S. Patent, the distance between 
principal points of the front and rear lens groups constituting the second 
lens group is set to be longer than the focal length of the front lens 
group. Therefore, an F-number of the lens structure is small and a back 
focus thereof is also short. However, a ratio of a maximum entire length 
of the lens structure to a focal length of the lens structure at a 
telescopic end thereof is equal to about 1.1 so that the maximum entire 
length cannot be necessarily reduced sufficiently. 
SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide a compact 
zoom lens having a high variable magnification in which the number of 
movable lens groups is reduced to two and an F-number of the zoom lens at 
a telescopic end thereof is equal to about 6 showing a bright state and a 
ratio of a maximum entire length of the zoom lens to a focal length of the 
zoom lens at the telescopic end thereof is equal to or less than one and a 
zooming region is widened by changing the focal length of the zoom lens 
from 36 mm to 102 mm and moving amounts of the movable lens groups at a 
zooming time of the zoom lens are reduced. 
The above object of the present invention can be achieved by a zoom lens 
having a high variable magnification in which first and second lens groups 
respectively having negative and positive focal lengths are sequentially 
arranged from an object side of the zoom lens to an image side thereof and 
a combined focal length of an entire lens system is changed by changing a 
distance between the first and second lens groups while the position of an 
image surface is constantly held, the zoom lens being constructed such 
that the second lens group is constructed by front and rear lens groups 
respectively having positive and negative focal lengths, and the 
respective focal lengths f.sub.1 and f.sub.2 of the first and second lens 
groups, the respective focal lengths f.sub.2 (F) and f.sub.2 (R) of the 
front and rear lens groups in the second lens group, and combined focal 
lengths f(W) and f(T) of the entire lens system at wide angle and 
telescopic ends thereof satisfy the following conditions. 
EQU [f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(W))-(f(W)/f.sub.1)}]/f(T)&lt;0.6(I) 
EQU [f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 
/f(T))-(f(T)/f.sub.1)}]/f(T)&lt;0.6(II) 
EQU 0.6&lt;.vertline.f.sub.2 (R).vertline./f.sub.2 (F)&lt;6.0 (III) 
EQU 0.8&lt;f.sub.2 (F)/f.sub.2 &lt;1.4 (IV) 
EQU 0.5&lt;.vertline.f.sub.1 .vertline./.sqroot.[f(W).multidot.f(T)]&lt;1.3(V) 
where .sqroot.[] means a square root of a value within bracket []. 
In accordance with a second lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a joining positive lens composed of a combination of positive and 
negative lenses, a positive lens, a negative lens, and a joining positive 
lens composed of a combination of positive and negative lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The rear lens group of the second lens group is constructed 
by a joining negative lens composed of a combination of negative and 
positive lenses. 
In accordance with a third lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a joining positive lens composed of a combination of positive and 
negative lenses, a positive lens, a negative lens, and a positive lens 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The rear lens group of the second lens group is constructed 
by a joining negative lens composed of a combination of negative and 
positive lenses. 
In accordance with a fourth lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a positive lens, a positive lens, and a negative lens sequentially 
arranged from the object side of the zoom lens to the image side thereof. 
The rear lens group of the second lens group is constructed by a joining 
lens composed of a combination of positive and negative lenses, and a 
negative lens sequentially arranged from the object side of the zoom lens 
to the image side thereof. 
In accordance with a fifth lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a positive lens and a joining lens composed of a combination of 
positive and negative lenses sequentially arranged from the object side of 
the zoom lens to the image side thereof. The rear lens group of the second 
lens group is constructed by a joining lens composed of a combination of 
positive and negative lenses, and a negative lens sequentially arranged 
from the object side of the zoom lens to the image side thereof. 
In accordance with a sixth lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a joining lens composed of a combination of positive and negative 
lenses, a positive lens, and a negative lens sequentially arranged from 
the object side of the zoom lens to the image side thereof. The rear lens 
group of the second lens group is constructed by a positive lens and a 
negative lens sequentially arranged from the object side of the zoom lens 
to the image side thereof. 
In accordance with a seventh lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a joining lens composed of a combination of positive and negative 
lenses, and a joining lens composed of a combination of positive and 
negative lenses sequentially arranged from the object side of the zoom 
lens to the image side thereof. The rear lens group of the second lens 
group is constructed by a positive lens and a negative lens sequentially 
arranged from the object side of the zoom lens to the image side thereof. 
In accordance with an eight lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a positive lens, a positive lens, and a joining lens composed of a 
combination of negative and positive lenses sequentially arranged from the 
object side of the zoom lens to the image side thereof. The rear lens 
group of the second lens group is constructed by a positive lens and a 
joining lens composed of a combination of negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. 
In accordance with a ninth lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a positive lens, a positive lens, and a joining lens composed of a 
combination of negative and positive lenses sequentially arranged from the 
object side of the zoom lens to the image side thereof. The rear lens 
group of the second lens group is constructed by a joining lens composed 
of a combination of positive and negative lenses, and a negative lens 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. 
In accordance with a tenth lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a joining lens composed of a combination of positive and negative 
lenses, a positive lens, and a joining lens composed of a combination of 
negative and positive lenses sequentially arranged from the object side of 
the zoom lens to the image side thereof. The rear lens group of the second 
lens group is constructed by a joining lens composed of a combination of 
positive and negative lenses, and a negative lens sequentially arranged 
from the object side of the zoom lens to the image side thereof. 
In accordance with an eleventh lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a positive lens, a joining lens composed of a combination of positive 
and negative lenses, and a joining lens composed of a combination of 
negative and positive lenses sequentially arranged from the object side of 
the zoom lens to the image side thereof. The rear lens group of the second 
lens group is constructed by a joining lens composed of a combination of 
positive and negative lenses, and a negative lens sequentially arranged 
from the object side of the zoom lens to the image side thereof. 
In accordance with a twelfth lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a joining lens composed of a combination of positive and negative 
lenses, and a joining lens composed of a combination of positive and 
negative lenses sequentially arranged from the object side of the zoom 
lens to the image side thereof. The rear lens group of the second lens 
group is constructed by a joining lens composed of a combination of 
positive and negative lenses, and a negative lens sequentially arranged 
from the object side of the zoom lens to the image side thereof. 
In accordance with a thirteenth lens structure of the present invention, 
the first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a positive lens, a positive lens, and a joining lens composed of a 
combination of negative and positive lenses sequentially arranged from the 
object side of the zoom lens to the image side thereof. The rear lens 
group of the second lens group is constructed by a joining lens composed 
of a combination of positive and negative lenses, and a joining lens 
composed of a combination of negative and positive lenses sequentially 
arranged from the object side of the zoom lens to the image side thereof. 
In accordance with a fourteenth lens structure of the present invention, 
the second lens group has a diaphragm between the front and rear lens 
groups. The zoom lens is constructed such that a moving amount of the 
diaphragm is smaller than that of the second lens group when a zooming 
operation is performed from the wide angle end of the zoom lens to the 
telescopic end thereof. 
In accordance with a fifteenth lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a positive lens, a positive lens, and a joining lens composed of a 
combination of negative and positive lenses sequentially arranged from the 
object side of the zoom lens to the image side thereof. The rear lens 
group of the second lens group is constructed by a joining lens composed 
of a combination of positive and negative lenses, and a negative lens 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. 
In accordance with a sixteenth lens structure of the present invention, the 
first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a joining lens composed of a combination of positive and negative 
lenses, a positive lens, and a joining lens composed of a combination of 
negative and positive lenses sequentially arranged from the object side of 
the zoom lens to the image side thereof. The rear lens group of the second 
lens group is constructed by a joining lens composed of a combination of 
positive and negative lenses, and a negative lens sequentially arranged 
from the object side of the zoom lens to the image side thereof. 
In accordance with a seventeenth lens structure of the present invention, 
the first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a positive lens, a joining lens composed of a combination of positive 
and negative lenses, and a joining lens composed of a combination of 
negative and positive lenses sequentially arranged from the object side of 
the zoom lens to the image side thereof. The rear lens group of the second 
lens group is constructed by a joining lens composed of a combination of 
positive and negative lenses, and a negative lens sequentially arranged 
from the object side of the zoom lens to the image side thereof. 
In accordance with an eighteenth lens structure of the present invention, 
the first lens group is constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The front lens group of the second lens group is constructed 
by a positive lens, a positive lens, and a joining lens composed of a 
combination of negative and positive lenses sequentially arranged from the 
object side of the zoom lens to the image side thereof. The rear lens 
group of the second lens group is constructed by a joining lens composed 
of a combination of positive and negative lenses, and a joining lens 
composed of a combination of negative and positive lenses sequentially 
arranged from the object side of the zoom lens to the image side thereof. 
In accordance with a nineteenth lens structure of the present invention, a 
distance between the front and rear lens groups in the second lens group 
is reduced in an intermediate zooming region of the zoom lens. 
In accordance with a twentieth lens structure of the present invention, a 
first diaphragm is disposed within the front lens group of the second lens 
group, or on an object side thereof, and a second diaphragm having a 
constant opening diameter is disposed between the front and rear lens 
groups of the second lens group. The second diaphragm is moved and 
separated from the front lens group of the second lens group when a 
zooming operation is performed from the wide angle end of the zoom lens to 
the telescopic end thereof. 
In accordance with a twenty-first lens structure of the present invention, 
a focusing operation is performed by moving the rear lens group of the 
second lens group on the image side thereof. The rear lens group of the 
second lens group includes at least one positive lens, and a lateral 
magnification m.sub.2 (RW) of the rear lens group in the second lens group 
at the wide angle end of the zoom lens and infinity with respect to a 
photographed object satisfies the following condition. 
EQU 1.1&lt;m.sub.2 (RW)&lt;2 
In accordance with a twenty-second lens structure of the present invention, 
a diaphragm is disposed between the front and rear lens groups in the 
second lens group. A moving amount of the diaphragm is set to be smaller 
than that of the second lens group when a zooming operation is performed 
from the wide angle end of the zoom lens to the telescopic end thereof. 
In accordance with the above structures, it is possible to provide a 
compact zoom lens having a high variable magnification in which the number 
of movable lens groups is reduced to two and an F-number of the zoom lens 
at the telescopic end thereof is equal to about 6 showing a bright state 
and a ratio of a maximum entire length of the zoom lens to a focal length 
of the zoom lens at the telescopic end thereof is equal to or less than 
one and a zooming region is widened by changing the focal length of the 
zoom lens from 36 mm to 102 mm and moving amounts of the movable lens 
groups at a zooming time of the zoom lens are reduced. 
Further objects and advantages of the present invention will be apparent 
from the following description of the preferred embodiments of the present 
invention as illustrated in the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The preferred embodiments of a zoom lens having a high variable 
magnification in the present invention will next be described in detail 
with reference to the accompanying drawings. 
As shown in FIG. 1, a zoom lens having a high variable magnification in the 
present invention, first and second lens groups I and II respectively 
having negative and positive focal lengths are sequentially arranged from 
an object side of the zoom lens to an image side thereof. A combined focal 
length of an entire lens system is changed by changing a distance between 
the first and second lens groups while the position of an image face IS is 
constantly held. This zoom lens has the following features. 
Namely, in this zoom lens, the second lens group II is constructed by front 
and rear lens groups II(F) and II(R) respectively having positive and 
negative focal lengths. The respective focal lengths f.sub.1 and f.sub.2 
of the first and second lens groups I and II, the respective focal lengths 
f.sub.2 (F) and f.sub.2 (R) of the front and rear lens groups II(F) and 
II(R) in the second lens group, and combined focal lengths f(W) and f(T) 
of the entire lens system at wide angle and telescopic ends thereof 
satisfy the following conditions, 
EQU [f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(W))-(f(W)/f.sub.1)}]/f(T)&lt;0.6(I) 
EQU [f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 
/f(T))-(f(T)/f.sub.1)}]/f(T)&lt;0.6(II) 
EQU 0.6&lt;.vertline.f.sub.2 (R).vertline./f.sub.2 (F)&lt;6.0 (III) 
EQU 0.8&lt;f.sub.2 (F)/f.sub.2 &lt;1.4 (IV) 
EQU 0.5&lt;.vertline.f.sub.1 .vertline./.sqroot.[f(W).multidot.f(T)]&lt;1.3(V) 
where .sqroot. [] means a square root of a value within bracket []. 
The first lens group I, the front lens group II(F) of the second lens 
group, and the rear lens group II(R) of the second lens group can be 
concretely constructed by various kinds of lens structures. 
Namely, in a second lens structure of the present invention, the first lens 
group is constructed by negative and positive lenses sequentially arranged 
from the object side of the zoom lens to the image side thereof. The front 
lens group of the second lens group is constructed by a joining positive 
lens composed of a combination of positive and negative lenses, a positive 
lens, a negative lens, and a joining positive lens composed of a 
combination of positive and negative lenses sequentially arranged from the 
object side of the zoom lens to the image side thereof. The rear lens 
group of the second lens group is constructed by a joining negative lens 
composed of a combination of negative and positive lenses. The lenses 
constituting the joining lens are sequentially arranged in an order from 
the object side of the zoom lens to the image side thereof. For example, 
in a combination of positive and negative lenses in the joining lens, this 
positive lens is arranged on the object side of the zoom lens and this 
negative lens is arranged on the image side of the zoom lens. 
In a third lens structure of the present invention, the first lens group is 
constructed by negative and positive lenses sequentially arranged from the 
object side of the zoom lens to the image side thereof. The front lens 
group of the second lens group is constructed by a joining positive lens 
composed of a combination of positive and negative lenses, a positive 
lens, a negative lens, and a positive lens sequentially arranged from the 
object side of the zoom lens to the image side thereof. The rear lens 
group of the second lens group is constructed by a joining negative lens 
composed of a combination of negative and positive lenses. 
In a fourth lens structure of the present invention, the first lens group 
is constructed by negative and positive lenses sequentially arranged from 
the object side of the zoom lens to the image side thereof. The front lens 
group of the second lens group is constructed by a positive lens, a 
positive lens, and a negative lens sequentially arranged from the object 
side of the zoom lens to the image side thereof. The rear lens group of 
the second lens group is constructed by a joining lens composed of a 
combination of positive and negative lenses, and a negative lens 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. 
In a fifth lens structure of the present invention, the first lens group is 
constructed by negative and positive lenses sequentially arranged from the 
object side of the zoom lens to the image side thereof. The front lens 
group of the second lens group is constructed by a positive lens and a 
joining lens composed of a combination of positive and negative lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The rear lens group of the second lens group is constructed 
by a joining lens composed of a combination of positive and negative 
lenses, and a negative lens sequentially arranged from the object side of 
the zoom lens to the image side thereof. 
In a sixth lens structure of the present invention, the first lens group is 
constructed by negative and positive lenses sequentially arranged from the 
object side of the zoom lens to the image side thereof. The front lens 
group of the second lens group is constructed by a joining lens composed 
of a combination of positive and negative lenses, a positive lens, and a 
negative lens sequentially arranged from the object side of the zoom lens 
to the image side thereof. The rear lens group of the second lens group is 
constructed by a positive lens and a negative lens sequentially arranged 
from the object side of the zoom lens to the image side thereof. 
In a seventh lens structure of the present invention, the first lens group 
is constructed by negative and positive lenses sequentially arranged from 
the object side of the zoom lens to the image side thereof. The front lens 
group of the second lens group is constructed by a joining lens composed 
of a combination of positive and negative lenses, and a joining lens 
composed of a combination of positive and negative lenses sequentially 
arranged from the object side of the zoom lens to the image side thereof. 
The rear lens group of the second lens group is constructed by a positive 
lens and a negative lens sequentially arranged from the object side of the 
zoom lens to the image side thereof. 
In an eighth lens structure of the present invention, the first lens group 
is constructed by negative and positive lenses sequentially arranged from 
the object side of the zoom lens to the image side thereof. The front lens 
group of the second lens group is constructed by a positive lens, a 
positive lens, and a joining lens composed of a combination of negative 
and positive lenses sequentially arranged from the object side of the zoom 
lens to the image side thereof. The rear lens group of the second lens 
group is constructed by a positive lens and a joining lens composed of a 
combination of negative and positive lenses sequentially arranged from the 
object side of the zoom lens to the image side thereof. 
In a ninth lens structure of the present invention, the first lens group is 
constructed by negative and positive lenses sequentially arranged from the 
object side of the zoom lens to the image side thereof. The front lens 
group of the second lens group is constructed by a positive lens, a 
positive lens, and a joining lens composed of a combination of negative 
and positive lenses sequentially arranged from the object side of the zoom 
lens to the image side thereof. The rear lens group of the second lens 
group is constructed by a joining lens composed of a combination of 
positive and negative lenses, and a negative lens sequentially arranged 
from the object side of the zoom lens to the image side thereof. 
In a tenth lens structure of the present invention, the first lens group is 
constructed by negative and positive lenses sequentially arranged from the 
object side of the zoom lens to the image side thereof. The front lens 
group of the second lens group is constructed by a joining lens composed 
of a combination of positive and negative lenses, a positive lens, and a 
joining lens composed of a combination of negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The rear lens group of the second lens group is constructed 
by a joining lens composed of a combination of positive and negative 
lenses, and a negative lens sequentially arranged from the object side of 
the zoom lens to the image side thereof. 
In an eleventh lens structure of the present invention, the first lens 
group is constructed by negative and positive lenses sequentially arranged 
from the object side of the zoom lens to the image side thereof. The front 
lens group of the second lens group is constructed by a positive lens, a 
joining lens composed of a combination of positive and negative lenses, 
and a joining lens composed of a combination of negative and positive 
lenses sequentially arranged from the object side of the zoom lens to the 
image side thereof. The rear lens group of the second lens group is 
constructed by a joining lens composed of a combination of positive and 
negative lenses, and a negative lens sequentially arranged from the object 
side of the zoom lens to the image side thereof. 
In a twelfth lens structure of the present invention, the first lens group 
is constructed by negative and positive lenses sequentially arranged from 
the object side of the zoom lens to the image side thereof. The front lens 
group of the second lens group is constructed by a joining lens composed 
of a combination of positive and negative lenses, and a joining lens 
composed of a combination of positive and negative lenses sequentially 
arranged from the object side of the zoom lens to the image side thereof. 
The rear lens group of the second lens group is constructed by a joining 
lens composed of a combination of positive and negative lenses, and a 
negative lens sequentially arranged from the object side of the zoom less 
to the image side thereof. 
In a thirteenth lens structure of the present invention, the first lens 
group is constructed by negative and positive lenses sequentially arranged 
from the object side of the zoom lens to the image side thereof. The front 
lens group of the second lens group is constructed by a positive lens, a 
positive lens, and a joining lens composed of a combination of negative 
and positive lenses sequentially arranged from the object side of the zoom 
lens to the image side thereof. The rear lens group of the second lens 
group is constructed by a joining lens composed of a combination of 
positive and negative lenses, and a joining lens composed of a combination 
of negative and positive lenses sequentially arranged from the object side 
of the zoom lens to the image side thereof. 
In a fourteenth lens structure of the present invention, a diaphragm can be 
arranged between the front and rear lens groups in the second lens group. 
In this case, the zoom lens can be constructed such that a moving amount 
of the diaphragm is smaller than that of the second lens group when a 
zooming operation is performed from the wide angle end of the zoom lens to 
the telescopic end thereof. 
In accordance with a fifteenth lens structure of the present invention, the 
first lens group can be constructed by negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof when the diaphragm can be arranged between the front and rear 
lens groups in the second lens group. The front lens group of the second 
lens group can be constructed by a positive lens, a positive lens, and a 
joining lens composed of a combination of negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The rear lens group of the second lens group can be 
constructed by a joining lens composed of a combination of positive and 
negative lenses, and a negative lens sequentially arranged from the object 
side of the zoom lens to the image side thereof. 
Otherwise, in accordance with a sixteenth lens structure of the present 
invention, the first lens group may be constructed by negative and 
positive lenses sequentially arranged from the object side of the zoom 
lens to the image side thereof. The front lens group of the second lens 
group may be constructed by a joining lens composed of a combination of 
positive and negative lenses, a positive lens, and a joining lens composed 
of a combination of negative and positive lenses sequentially arranged 
from the object side of the zoom lens to the image side thereof. The rear 
lens group of the second lens group may be constructed by a joining lens 
composed of a combination of positive and negative lenses, and a negative 
lens sequentially arranged from the object side of the zoom lens to the 
image side thereof. 
Further, in accordance with a seventeenth lens structure of the present 
invention, the first lens group can be constructed by negative and 
positive lenses sequentially arranged from the object side of the zoom 
lens to the image side thereof. The front lens group of the second lens 
group can be constructed by a positive lens, a joining lens composed of a 
combination of positive and negative lenses, and a joining lens composed 
of a combination of negative and positive lenses sequentially arranged 
from the object side of the zoom lens to the image side thereof. The rear 
lens group of the second lens group can be constructed by a joining lens 
composed of a combination of positive and negative lenses, and a negative 
lens sequentially arranged from the object side of the zoom lens to the 
image side thereof. 
Further, in accordance with an eighteenth lens structure of the present 
invention, the first lens group can be constructed by negative and 
positive lenses sequentially arranged from the object side of the zoom 
lens to the image side thereof. The front lens group of the second lens 
group can be constructed by a positive lens, a positive lens, and a 
joining lens composed of a combination of negative and positive lenses 
sequentially arranged from the object side of the zoom lens to the image 
side thereof. The rear lens group of the second lens group can be 
constructed by a joining lens composed of a combination of positive and 
negative lenses, and a joining lens composed of a combination of negative 
and positive lenses sequentially arranged from the object side of the zoom 
lens to the image side thereof. 
In accordance with a nineteenth lens structure of the present invention, 
the zoom lens can be constructed such that a distance between the front 
and rear lens groups in the second lens group is reduced in an 
intermediate zooming region of the zoom lens. 
In accordance with a twentieth lens structure of the present invention, a 
first diaphragm can be disposed within the front lens group of the second 
lens group, or on an object side thereof in the first or nineteenth lens 
structure of the present invention. In this case, a second diaphragm 
having a constant opening diameter can be disposed between the front and 
rear lens groups of the second lens group. The second diaphragm is moved 
and separated from the front lens group of the second lens group when a 
zooming operation is performed from the wide angle end of the zoom lens to 
the telescopic end thereof. 
In accordance with a twenty-first lens structure of the present invention, 
a focusing operation is performed by moving the rear lens group of the 
second lens group on the image side thereof. The rear lens group of the 
second lens group includes at least one positive lens. A lateral 
magnification m.sub.2 (RW) of the rear lens group in the second lens group 
at the wide angle end of the zoom lens and infinity with respect to a 
photographed object satisfies the following condition. 
EQU 1.1&lt;m.sub.2 (RW)&lt;2 
In accordance with a twenty-second lens structure of the present invention, 
a diaphragm can be disposed between the front and rear lens groups of the 
second lens group in the twenty-first lens structure. A moving amount of 
this diaphragm can be set to be smaller than that of the second lens group 
when a zooming operation is performed from the wide angle end of the zoom 
lens to the telescopic end thereof. 
In a zoom lens shown in FIG. 1, a first lens group I having a negative 
focal length and a second lens group II having a positive focal length are 
sequentially arranged from an object side of the zoom lens to an image 
side thereof. In the following description, the focal lengths of the first 
and second lens groups in the above zoom lens are respectively set to 
f.sub.1 and f.sub.2. A magnification of the second lens group is set to 
m.sub.2. Further, reference numeral TL designates an entire length of a 
lens system when each of the lens groups is approximately set to be thin. 
Namely, this entire length TL is equal to a distance from a principal 
point of the first lens group on a front side thereof to a focal point of 
the entire lens system. In this case, this distance TL is provided by the 
following formula. 
EQU TL=f.sub.1 +f.sub.2 .multidot.{2-(1/m.sub.2)-m.sub.2 } (1) 
Further, reference numerals f(W) and f(T) respectively designate combined 
focal lengths of the entire lens system at wide angle and telescopic ends 
of the zoom lens. Reference numerals m.sub.2 (W) and m.sub.2 (T) 
respectively designate magnifications of the second lens group at the wide 
angle and telescopic ends of the zoom lens. In this case, the following 
formulas are formed with respect to the above combined focal lengths and 
the above magnifications. 
EQU f(W)=f.sub.1 .multidot.m.sub.2 (W) (2) 
EQU f(T)=f.sub.1 .multidot.m.sub.2 (T) (3) 
Accordingly, entire lengths TL(W) and TL(T) of the lens system at the wide 
angle and telescopic ends of the zoom lens are represented by the 
following formulas. 
EQU TL(W)=f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(W))-(f(W)/f.sub.1)}(4) 
EQU TL(T)=f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(T))-(f(T)/f.sub.1)}(5) 
Since the focal length f.sub.1 of the first lens group is negative, the 
entire lengths TL(W) and TL(T) are reduced as the focal length f.sub.2 is 
reduced. 
The above formulas (4) and (5) are partially differentiated as follows with 
respect to the focal length f.sub.1. 
EQU .differential.TL(W)=[{f.sub.1.sup.2 .multidot.(f(W)-f.sub.2)+f.sub.2 
.multidot.f(W).sup.2 }/{f.sub.1.sup.2 
.multidot.f(W)}].differential.f.sub.1(6) 
EQU .differential.TL(T)=[{f.sub.1.sup.2 .multidot.(f(T)-f.sub.2)+f.sub.2 
.multidot.f(T).sup.2 }/{f.sub.1.sup.2 
.multidot.f(T)}].differential.f.sub.1(7) 
From the above formulas (6) and (7), it is understood that the above entire 
lengths TL(W) and TL(T) are reduced as an absolute focal length 
.vertline.f.sub.1 .vertline. is increased when {f(W)-f.sub.2 }&gt;0, and 
{f(T)-f.sub.2 }&gt;0. Namely, the above entire lengths TL(W) and TL(T) are 
reduced as the negative forcal length f.sub.1 is decreased when 
{f(W)-f.sub.2 }&gt;0, and {f(T)-f.sub.2 }&gt;0. 
Accordingly, there are the following two methods for reducing the entire 
length of the lens system. 
1 The focal length f.sub.1 is reduced. 
2 The focal length f.sub.2 is reduced. 
It is preferable to simultaneously satisfy the above-mentioned conditional 
inequalities (I) and (II) with respect to the focal lengths f.sub.1 and 
f.sub.2. When these conditional inequalities are not satisfied, the entire 
length of the lens system is too long when the lens groups are 
approximately set to be thin. Therefore, when the lens system is really 
constructed by thick lenses, it is difficult to reduce and set a ratio of 
a maximum entire length of the lens system to a focal length thereof at 
the telescopic end of the zoom lens to a value equal to or less than one. 
A distance D(T) between principal points of the first and second lens 
groups at the telescopic end of the zoom lens is provided by the following 
formula. 
EQU D(T)=f.sub.1 +f.sub.2 -}f.sub.1 .multidot.f.sub.2 /f(T)} (8) 
The above formula (8) is partially differentiated as follows with respect 
to the respective focal lengths f.sub.1 and f.sub.2. 
EQU .differential.D(T)={1-f.sub.2 /f(T)}.multidot..differential.f.sub.1, 
.differential.D(T)={1-f.sub.1 /f(T)}.multidot..differential.f.sub.2 
Accordingly, the distance D(T) is reduced as the focal lengths f.sub.1 and 
f.sub.2 are reduced. 
In other words, when one or both of the focal lengths f.sub.1 and f.sub.2 
are reduced to reduce the entire length of the lens system, the distance 
D(T) between the principal points of the first and second lens groups is 
reduced. Accordingly, when the lens system is really constructed by 
lenses, it is difficult to substantially secure distances between these 
lenses. 
There are two methods for solving this problem. In a first method, a 
principal point of the first lens group on a rear side thereof is moved 
toward the second lens group. In a second method, a principal point of the 
second lens group on a front side thereof is moved toward the first lens 
group. 
The first method is disadvantageous since the entire length of the lens 
system is increased since the first lens group is really located on the 
object side. In the second method, a back focus of the lens system is 
reduced, but no entire length thereof is changed. Accordingly, the second 
method can be used in a lens shutter camera. 
An arrangement of refracting power for moving the principal point of the 
second lens group on the front side thereof toward the first lens group 
will next be described. It is necessary that the second lens group is 
constructed by a front lens group having a positive focal length and a 
rear lens group having a negative focal length to move the principal point 
of the second lens group on the front side thereof toward the first lens 
group. 
In the following description, f.sub.2 (F) and f.sub.2 (R) respectively 
designate focal lengths of the front lens group II(F) and the rear lens 
group II(R) constituting the second lens group. Reference numeral D.sub.2 
designates a distance between principal points of the front and rear lens 
groups. Further, reference numeral H.sub.2 designates a distance from a 
principal point of the front lens group on a front side thereof to the 
principal point of the second lens group on the front side thereof. In 
this case, this distance H.sub.2 is represented by the following formula. 
EQU H.sub.2 =f.sub.2 .multidot.D.sub.2 /f.sub.2 (R) (9) 
Otherwise, this distance H.sub.2 is represented by the following formula. 
EQU H.sub.2 =f.sub.2 (F).multidot.D.sub.2 /{f.sub.2 (F)+f.sub.2 (R)-D.sub.2 
}(10) 
The formula (10) is partially differentiated as follows with respect to the 
focal length f.sub.2 (F). 
EQU .differential.H.sub.2 =[{D.sub.2 .multidot.(f.sub.2 (R)-D.sub.2)}/{f.sub.2 
(F)+f.sub.2 (R)-D.sub.2)}.sup.2 ].multidot..differential.f.sub.2 (F) 
From this formula, it is understood that the distance H.sub.2 is reduced as 
the focal length f.sub.2 (F) is increased. 
The formula (10) is partially differentiated as follows with respect to the 
focal length f.sub.2 (R). 
EQU .differential.H.sub.2 =[{-f.sub.2 (F).multidot.D.sub.2 }/{f.sub.2 
(F)+f.sub.2 (R)-D.sub.2 }.sup.2 ].multidot..differential.f.sub.2 (R) 
From this formula, it is understood that the distance H.sub.2 is reduced as 
the focal length f.sub.2 (R) is increased. 
Further, the formula (10) is partially differentiated as follows with 
respect to the distance D.sub.2. 
EQU .differential.H.sub.2 =[f.sub.2 (F).multidot.{f.sub.2 (F)+f.sub.2 
(R)}/{f.sub.2 (F)+f.sub.2 (R)-D.sub.2).sup.2 
}.multidot..differential.D.sub.2 
From this formula, the following two conditions for reducing the distance 
H.sub.2 are obtained. 
1 The distance D.sub.2 is decreased when f.sub.2 (F)+f.sub.2 (R)&gt;0. 
2 The distance D.sub.2 is increased when f.sub.2 (F)+f.sub.2 (R)&lt;0. 
When the distance H.sub.2 is negative, the principal point of the second 
lens group II on the front side thereof is located on a side of the first 
lens group from the principal point of the front lens group on the front 
side thereof in the second lens group. The focal length f.sub.2 (F) of the 
front lens group in the second lens group satisfies the following formula. 
EQU f.sub.2 ={f.sub.2 (F).multidot.f.sub.2 (R)/{f.sub.2 (F)+f.sub.2 (R)-D.sub.2 
} (11) 
In this formula, f.sub.2 (F)+f.sub.2 (R)-D.sub.2 &lt;0 is obtained since 
f.sub.2 &lt;0, f.sub.2 (F)&gt;0, and f.sub.2 (R)&lt;0. The above conditions are 
shown by solid lines in FIG. 217. 
A paraxial condition for reducing the focal length f.sub.2 of the second 
lens group will next be described when the second lens group II is 
constructed by the front lens group II(F) and the rear lens group II(R) as 
mentioned above. 
The formula (11) is partially differentiated as follows with respect to the 
focal length f.sub.2 (F). 
EQU .differential.f.sub.2 =[(f.sub.2 (R).multidot.{f.sub.2 (R)-D.sub.2 
}/{f.sub.2 (F)+f.sub.2 (R)-D.sub.2 }.sup.2 ].differential.f.sub.2 (F)(12) 
From this formula (12), it is understood that the focal length f.sub.2 is 
reduced as the focal length f.sub.2 (F) is reduced. 
The formula (11) is partially differentiated as follows with respect to the 
focal length f.sub.2 (R). 
EQU .differential.f.sub.2 =[(f.sub.2 (F).multidot.{f.sub.2 (F)-D.sub.2 
})/{f.sub.2 (F)+f.sub.2 (R)-D.sub.2 }.sup.2 ].differential.f.sub.2 (R)(13) 
Accordingly, the following two conditions for reducing the focal length 
f.sub.2 are obtained. 
1 The focal length f.sub.2 (R) is reduced and .vertline.f.sub.2 
(R).vertline. is increased when {f.sub.2 (F)-D.sub.2 }&gt;0, i.e., f.sub.2 
(F)&lt;f.sub.2. 
2 The focal length f.sub.2 (R) is increased and .vertline.f.sub.2 
(R).vertline. is decreased when {f.sub.2 (F)-D.sub.2 }&lt;0, i.e., f.sub.2 
(F)&gt;f.sub.2. 
With respect to these two conditions, the focal length f.sub.2 in the 
second condition can be further reduced in comparison with that in the 
first condition. 
The above formula (11) is partially differentiated as follows with respect 
to the distance D.sub.2. 
EQU .differential.f.sub.2 =[{f.sub.2 (F).multidot.f.sub.2 (R)}/{f.sub.2 
(F)+f.sub.2 (R)-D.sub.2 }.sup.2 ].differential.D.sub.2 (14) 
From this formula (14), it is understood that the focal length f.sub.2 is 
reduced as the distance D.sub.2 is increased. 
The above conditions are shown by solid lines in FIG. 218. 
A paraxial condition of the second lens group for reducing the entire 
length of the lens system and securing the distance between the lens 
groups is summarized in the following table when the lens system is 
constructed by thin lenses. 
______________________________________ 
Reduction of the entire 
Security for the distance 
length of the lens system 
between the lens groups 
f.sub.2 :small H.sub.2 :small 
______________________________________ 
f.sub.2 (F) 
small large 
.vertline.f.sub.2 (R).vertline. 
[small when [small] 
f.sub.2 (F) - D.sub.2 &lt; 0] 
D.sub.2 
[large] [large when 
f.sub.2 (F) + f.sub.2 (R) &lt; 0] 
small when 
f.sub.2 (F) + f.sub.2 (R) &gt; 0 
______________________________________ 
In the above table, a preferable condition for reducing the entire length 
of the lens system and securing the distance between the lens groups is 
provided by contents surrounded by bracket []. 
An arrangement of refracting power will next be described when aberration 
is considered in the lens system constructed by thick lenses. 
A changing amount of the distance between the first and second lens groups 
will next be described when a zooming operation is performed from the wide 
angle end of the zoom lens to the telescopic end thereof. As shown in FIG. 
1, reference numeral D(W) designates a distance between principal points 
of the first lens group I and the second lens group II at the wide angle 
end of the zoom lens. Reference numeral D(T) designates a distance between 
principal points of the first lens group I and the second lens group II at 
the telescopic end of the zoom lens. In this case, the distances D(W) and 
D(T) are respectively provided by the following formulas. 
EQU D(W)=f.sub.1 +f.sub.2 -{f.sub.1 .multidot.f.sub.2 /f(W)} (15) 
EQU D(T)=f.sub.1 +f.sub.2 -{f.sub.1 .multidot.f.sub.2 /f(T)} (8) 
Accordingly, when the zooming operation is performed from the wide angle 
end of the zoom lens to the telescopic end thereof, the changing amount 
.DELTA.D(=D(W)-D(T)) of the distance between the above principal points is 
provided by the following formula. 
EQU .DELTA.D=f.sub.1 .multidot.f.sub.2 .multidot.[{1/f(T)}-{1/f(W)}](16) 
From this formula, it is understood that the changing amount .DELTA.D is 
increased as the focal lengths .vertline.f.sub.1 .vertline. and f.sub.2 
are increased. Accordingly, in the actual lens construction, it is 
necessary that the distance between the first lens group I and the second 
lens group II is increased as the focal lengths .vertline.f.sub.1 
.vertline. and f.sub.2 are increased. 
At this time, it is necessary to reduce thicknesses of the lens groups in 
the second lens group and reduce a back focus of the lens system at the 
wide angle end of the zoom lens so as to secure the distance between the 
lens groups while the entire length of the lens system is reduced. 
Therefore, it is difficult to preferably construct the lens system. 
Further, a diameter of the first lens group is increased when a diaphragm 
is disposed in the second lens group. 
In contrast to this, when the absolute focal length .vertline.f.sub.1 
.vertline. is reduced, the focal length f.sub.2 must be also reduced to 
reduce the entire length of the lens system. However, as shown in the 
above table, to reduce the focal length f.sub.2, it is necessary to reduce 
the focal length f.sub.2 (F), reduce the absolute focal length 
.vertline.f.sub.2 (R).vertline. under the condition of f(F)&lt;D.sub.2, or 
increase the distance D.sub.2. 
When the focal lengths f.sub.2 (F) and .vertline.f.sub.2 (R).vertline. are 
excessively reduced, it is difficult to correct aberration of the lens 
system. When the absolute focal length .vertline.f.sub.2 (R).vertline. is 
excessively reduced or the distance D.sub.2 is excessively increased, it 
is difficult to secure the back focus of the lens system and correct a 
Petzval's sum. 
In consideration of the above-mentioned contents, the following inequality 
is obtained as a range of the focal length f.sub.1 suitable for security 
for the distance between the lens groups while the entire length of the 
lens system is reduced. 
EQU 0.5&lt;.vertline.f.sub.1 .vertline..sqroot.[f(W).multidot.f(T)]&lt;1.3 
This determined inequality is provided as the above-mentioned condition (V) 
with respect to the zoom lens of the present invention. In this 
inequality, notation .sqroot.[] means a square root of a value within this 
bracket []. 
The above-mentioned condition (III) will next be described. 
When the focal length of the second lens group is reduced and the distance 
between the first and second lens groups is secured, it is preferable to 
reduce the absolute focal length .vertline.f.sub.2 (R).vertline. under the 
condition of f.sub.2 (F)&lt;D.sub.2 and increase the distance D.sub.2 under 
the condition of f.sub.2 (R)+f.sub.2 (F)&lt;0 from the above-mentioned table. 
In consideration of these contents, the relation between the absolute focal 
length .vertline.f.sub.2 (R).vertline. and the focal length f.sub.2 (F) is 
determined and provided as the following condition (III). 
EQU 0.6&lt;.vertline.f.sub.2 (R).vertline./f.sub.2 (F)&lt;6.0 
When the ratio in this condition (III) exceeds a lower limit thereof, it is 
difficult to reduce the entire length of the lens system since such an 
exceeding condition is greatly shifted from the above condition for 
reducing the focal length of the second lens group and securing the 
distance between the first and second lens groups. 
Further, the absolute focal length .vertline.f.sub.2 (R).vertline. of the 
rear lens group in the second lens group II is excessively reduced so that 
it is difficult to correct the Petzval's sum and secure the back focus of 
the lens system. 
In contrast to this, when the ratio in the condition (III) exceeds an upper 
limit thereof, the entire length of the lens system can be reduced by 
increasing the distance between the principal points of the front and rear 
lens groups in the second lens group. However, in this case, it is 
difficult to secure the back focus of the lens system, or the focal length 
of the front lens group in the second lens group II is excessively 
reduced. Therefore, it is difficult to correct aberration of the lens 
system and secure the distance between the first and second lens groups. 
The above condition (IV) will next be described. 
When the focal length f.sub.2 is reduced and the principal point of the 
second lens group on the front side thereof is moved on a side of the 
first lens group, it is preferable to reduce the absolute focal length 
.vertline.f.sub.2 (R).vertline. under the condition of f.sub.2 
(F)&lt;D.sub.2, or increase the distance D.sub.2 under the condition of 
f.sub.2 (F)+f.sub.2 (R)&lt;0 in accordance with the above-mentioned table. At 
this time, the relation between the focal lengths f.sub.2 and f.sub.2 (F) 
is determined and provided as the following condition (IV). 
EQU 0.8&lt;f.sub.2 (F)/f.sub.2 &lt;1.4 
When the ratio in this condition (IV) is equal to or less than one, no 
condition of f.sub.2 (F) &lt;D.sub.2 is satisfied so that the focal length 
f.sub.2 cannot be reduced by the rear lens group of the second lens group 
II. 
Accordingly, when the ratio in the condition (IV) exceeds a lower limit 
thereof, it is difficult to secure the distance between the first and 
second lens groups, and the focal length f.sub.2 (F) of the front lens 
group in the second lens group is excessively reduced. Therefore, it is 
difficult to correct aberration of the lens system. In contrast to this, 
when the ratio in the condition (IV) exceeds an upper limit thereof, the 
focal length f.sub.2 of the second lens group is greatly reduced by the 
rear lens group in the second lens group II. However, in this case, the 
absolute focal length .vertline.f.sub.2 (R).vertline. is excessively 
reduced, or the distance D.sub.2 between the principal points of the front 
and rear lens groups in the second lens group is excessively increased. 
Therefore, it is difficult to correct the Petzval's sum and secure the 
back focus of the lens system. 
The respective lens groups are constructed as follows. 
It is preferable to construct the first lens group I by two lenses as a 
minimum number of lenses for correcting aberration of the first lens group 
so as to set the first lens group to be thin. 
In second to thirteenth lens structures of the present invention and 
fifteenth to eighteenth lens structures of the present invention, negative 
and positive lenses are sequentially arranged from an object side of the 
zoom lens to an image side thereof, thereby constituting the first lens 
group. Aberration caused within the first lens group is reduced by such a 
lens arrangement and a wide angle operation can be performed by such a 
lens arrangement. 
When the first lens group is constructed by these negative and positive 
lenses, it is preferable to satisfy the following condition, 
EQU .nu..sub.1 (N)&gt;.nu..sub.1 (P) 
to reduce chromatic aberration caused within the first lens group when Abbe 
numbers of the negative and positive lens are respectively set to 
.nu..sub.1 (N) and .nu..sub.1 (P). 
When this condition is not satisfied, it is difficult to sufficiently 
correct axial chromatic aberration and chromatic aberration of 
magnification within the first lens group. Accordingly, the chromatic 
aberration of the entire lens system caused by a zooming operation of the 
zoom lens is greatly changed. 
The second lens group II can be constructed by various kinds of lenses. 
The second lens structure of the present invention will next be described. 
In the second lens structure, the front lens group in the second lens group 
is constructed by sequentially arranging a positive lens composed of a 
combination of positive and negative lenses; a positive lens; a negative 
lens; and a positive lens composed of a combination of positive and 
negative lenses from the object side of the zoom lens to the image side 
thereof. The rear lens group in the second lens group is constructed by a 
negative lens composed of a combination of negative and positive lenses. 
The front lens group in the second lens group performs an image forming 
action of the entire zoom lens and has strong positive refracting power. 
An axial light beam is widest since a light beam diverged by the first 
lens group is converged. Accordingly, an amount of aberration caused in 
the front lens group tends to be increased. Therefore, in the front lens 
group, the positive lens in the above first combination and the subsequent 
positive lens are used to reduce this aberration amount. The above 
negative lens is arranged after these two positive lenses to correct 
aberration caused by these two positive lenses. The combined positive lens 
for assisting the image forming action of the zoom lens is arranged as a 
final lens of the front lens group. 
At this time, refracting powers of the two positive lenses arranged on the 
object side of the zoom lens are preferably increased, and a focal length 
of the front lens group until the negative lens as a third lens of the 
front lens group in the second lens group is preferably set to be positive 
to secure the distance between the first and second lens groups and reduce 
and hold the focal length of the second lens group. 
Since a first lens of the front lens group is composed of the above 
combined lens, it is possible to mainly correct axial chromatic aberration 
and chromatic aberration of magnification in the second lens group. In 
this case, it is preferable to satisfy the following condition, 
EQU .nu..sub.2 (FP)&gt;.nu..sub.2 (FN) 
when Abbe numbers of the positive and negative lenses constituting the 
first lens of the front lens group are respectively set to .nu..sub.2 (FP) 
and .nu..sub.2 (FN). 
When this condition is not satisfied, it is insufficient to correct the 
chromatic aberrations within the second lens group. 
In the second lens group, each of the lenses of the front lens group on 
most object and image sides thereof is composed of a combination of 
positive and negative lenses. Accordingly, it is possible to correct 
spherical aberration in the front lens group by setting a refractive index 
of the negative lens in each of these combined lenses to be larger than 
that of the positive lens in each of these combined lenses. 
Further, since the rear lens group in the second lens group is constructed 
by the above negative lens composed of a combination of negative and 
positive lenses, it is possible to mainly correct the chromatic aberration 
of magnification with respect to aberrations caused in the rear lens 
group. 
It is preferable to satisfy the following condition, 
EQU .nu..sub.2 (RN)&gt;.nu..sub.2 (RP) 
when Abbe numbers of the negative and positive lenses of the combined lens 
constituting the rear lens group are respectively set to .nu..sub.2 (RN) 
and .nu..sub.2 (RP). When this condition is not satisfied, it is 
impossible to correct the chromatic aberration of magnification in the 
rear lens group of the second lens group. Therefore, the chromatic 
aberration of magnification of the entire lens system caused by a zooming 
operation of the zoom lens is greatly changed. 
It is desirable to use an aspherical lens surface within the front lens 
group so as to preferably correct spherical aberration caused within the 
front lens group of the second lens group. Further, aberration outside an 
optical axis of the lens system can be suitably held by using an 
aspherical lens surface in the rear lens group of the second lens group on 
the object or image side thereof. 
In the third lens structure of the present invention, the front lens group 
in the second lens group is constructed by sequentially arranging a 
joining positive lens composed of a combination of positive and negative 
lenses; a positive lens; a negative lens; and a positive lens from the 
object side of the zoom lens to the image side thereof. Ther rear lens 
group in the second lens group is constructed by a joining negative lens 
composed of a combination of negative and positive lenses. 
As mentioned above, an amount of aberration tends to be increased in the 
front lens group of the second lens group. To reduce this aberration 
amount, the two positive lenses are arranged on the object side of the 
second lens group in the third lens structure of the present invention. 
One of these two positive lenses is constructed by the joining positive 
lens. The negative lens is arranged after these two positive lenses and 
the positive lens for assisting an image forming action is finally 
arranged on an image side of this negative lens to correct aberration 
caused by the above two positive lenses. 
In this case, refracting powers of the above two positive lenses on the 
object side of the second lens group are preferably increased and a focal 
length of the second lens group until the negative lens subsequent to 
these two positive lenses is preferably set to be positive so as to secure 
the distance between the first and second lens groups and reduce and hold 
the focal length of the second lens group. 
Axial chromatic aberration and chromatic aberration of magnification within 
the second lens group are mainly corrected by constructing a lens of the 
front lens group on the most object side thereof by the joining positive 
lens composed of a combination of positive and negative lenses. 
Accordingly, it is preferable to satisfy the following condition, 
EQU .nu..sub.2 (FP)&gt;.nu..sub.2 (FN) 
when Abbe numbers of the positive and negative lenses in this joining 
positive lens are respectively set to .nu..sub.2 (FP) and .nu..sub.2 (FN). 
When this condition is not satisfied, it is insufficient to correct the 
chromatic aberrations within the second lens group. 
Spherical aberration of the front lens group can be corrected by setting a 
refractive index of the negative lens in the joining positive lens on the 
most object side of the front lens group in the second lens group to be 
larger than that of the positive lens in this joining positive lens. 
The rear lens group in the second lens group is constructed by the joining 
negative lens composed of a combination of negative and positive lenses to 
mainly correct the chromatic aberration of magnification with respect to 
aberrations caused in the rear lens group. 
It is preferable to satisfy the following condition, 
EQU .nu..sub.2 (RN)&gt;.nu..sub.2 (RP) 
when Abbe numbers of the negative and positive lenses of the joining 
negative lens constituting the rear lens group are respectively set to 
.nu..sub.2 (RN) and .nu..sub.2 (RP). 
When this condition is not satisfied, it is impossible to correct the 
chromatic aberration of magnification in the rear lens group of the second 
lens group. Therefore, the chromatic aberration of magnification of the 
entire lens system caused by a zooming operation of the zoom lens is 
greatly changed. 
In the third lens structure of the present invention, it is desirable to 
use an aspherical lens surface within the front lens group so as to 
preferably correct spherical aberration caused within the front lens group 
of the second lens group. Further, aberration outside an optical axis of 
the lens system can be suitably held by using an aspherical lens surface 
on the object or image side of the joining negative lens in the rear lens 
group of the second lens group. 
In the fourth lens structure of the present invention, the front lens group 
in the second lens group is constructed by sequentially arranging a 
positive lens; a positive lens; and a negative lens from the object side 
of the zoom lens to the image side thereof. The rear lens group in the 
second lens group is constructed by sequentially arranging a joining lens 
composed of a combination of positive and negative lenses; and a negative 
lens from the object side of the zoom lens to the image side thereof. 
In the front lens group, the first two positive lenses are used to reduce 
aberration caused in the front lens group. The negative lens is arranged 
after these two positive lenses to locate a principal point of the front 
lens group on a front side thereof on the object side of the second lens 
group and correct aberration caused by these two positive lenses. 
A Petzval's sum can be corrected by setting a refractive index of this 
negative lens to be larger than an average of refractive indexes of the 
two positive lenses on the object side of this negative lens. 
It is preferable to satisfy the following condition, 
EQU .nu..sub.2 (FP)&gt;.nu..sub.2 (FN) 
when an average of Abbe numbers of the two positive lenses of the front 
lens group in the second lens group is set to .nu..sub.2 (FP) and an Abbe 
number of the negative lens of the front lens group is set to .nu..sub.2 
(FN). 
When this condition is not satisfied, it is insufficient to correct 
chromatic aberration within the second lens group. 
Refracting power of the front lens group in the second lens group can be 
reduced by increasing the distance between principal points of the front 
and rear lens groups in the second lens group. 
In the fourth lens structure of the present invention, the rear lens group 
in the second lens group is constructed by sequentially arranging a 
joining lens composed of a combination of positive and negative lenses; 
and a negative lens from the object side of the zoom lens to the image 
side thereof so as to reduce the above refracting power of the front lens 
group while a back focus of the lens system is secured. 
It is preferable to satisfy the following condition, 
EQU .nu..sub.2 (RN)&gt;.nu..sub.2 (RP) 
when Abbe numbers of the positive and negative lenses of the joining lens 
used in the rear lens group are respectively set to .nu..sub.2 (RP) and 
.nu..sub.2 (RN). 
When this condition is not satisfied, it is impossible to correct chromatic 
aberration of magnification in the rear lens group of the second lens 
group. Therefore, the chromatic aberration of magnification of the entire 
lens system caused by a zooming operation of the zoom lens is greatly 
changed. 
It is desirable to use an aspherical lens surface within the front lens 
group so as to preferably correct spherical aberration caused within the 
front lens group of the second lens group. Further, aberration outside an 
optical axis of the lens system can be suitably held by using an 
aspherical lens surface within the rear lens group of the second lens 
group. 
In the fifth lens structure of the present invention, the front lens group 
in the second lens group is constructed by sequentially arranging a 
positive lens; and a joining lens composed of a combination of positive 
and negative lenses from the object side of the zoom lens to the image 
side thereof. The rear lens group in the second lens group is constructed 
by sequentially arranging a joining lens composed of a combination of 
positive and negative lenses; and a negative lens from the object side of 
the zoom lens to the image side thereof. 
In the front lens group, the two positive lenses are used to reduce an 
amount of aberration caused in the front lens group. The negative lens is 
arranged after these two positive lenses to correct aberration caused by 
these two positive lenses. 
When a joining lens is constructed by combining the final negative lens of 
the front lens group with the positive lens on the object side of this 
negative lens and a refractive index of this negative lens is set to be 
larger than that of this positive lens, it is possible to locate a 
principal point of the front lens group on a front side thereof on the 
object side of the second lens group and correct aberration caused in this 
positive lens on a joining face of the joining lens. 
It is preferable to satisfy the following condition, 
EQU .nu..sub.2 (FP)&gt;.nu..sub.2 (FN) 
when Abbe numbers of the positive and negative lenses in the joining lens 
of the front lens group in the second lens group are respectively set to 
.nu..sub.2 (FP) and .nu..sub.2 (FN). 
When this condition is not satisfied, it is insufficient to correct 
chromatic aberration within the second lens group. 
Refracting power of the front lens group in the second lens group can be 
reduced by increasing the distance between principal points of the front 
and rear lens groups in the second lens group. 
In the fifth lens structure of the present invention, the rear lens group 
in the second lens group is constructed by sequentially arranging a 
joining lens composed of a combination of positive and negative lenses; 
and a negative lens from the object side of the zoom lens to the image 
side thereof so as to reduce the above refracting power of the front lens 
group while a back focus of the lens system is secured. 
It is preferable to satisfy the following condition, 
EQU .nu..sub.2 (RN)&gt;.nu..sub.2 (RP) 
when Abbe numbers of the positive and negative lenses of the joining lens 
used in the rear lens group are respectively set to .nu..sub.2 (RP) and 
.nu..sub.2 (RN). 
When this condition is not satisfied, it is impossible to correct chromatic 
aberration of magnification in the rear lens group of the second lens 
group. Therefore, the chromatic aberration of magnification of the entire 
lens system caused by a zooming operation of the zoom lens is greatly 
changed. 
It is desirable to use an aspherical lens surface within the front lens 
group so as to preferably correct spherical aberration caused within the 
front lens group of the second lens group. Further, aberration outside an 
optical axis of the lens system can be suitably held by using an 
aspherical lens surface within the rear lens group of the second lens 
group. 
In the sixth lens structure of the present invention, the front lens group 
in the second lens group is constructed by sequentially arranging a 
joining lens composed of a combination of positive and negative lenses; a 
positive lens; and a negative lens from the object side of the zoom lens 
to the image side thereof. This joining lens is constructed as a positive 
lens. The rear lens group in the second lens group is constructed by 
sequentially arranging a positive lens and a negative lens from the object 
side of the zoom lens to the image side thereof. 
In the front lens group, the two positive lenses are used to reduce an 
amount of aberration caused in the front lens group. One of these two 
positive lenses is constructed by the joining lens. The negative lens is 
arranged after these two positive lenses to locate a principal point of 
the front lens group on a front side thereof on the object side of the 
second lens group and correct aberration caused by these two positive 
lenses. 
A first positive lens in the front lens group is constructed by the above 
joining lens composed of a combination of positive and negative lenses to 
correct axial chromatic aberration and chromatic aberration of 
magnification within the second lens group. Accordingly, it is preferable 
to satisfy the following condition, 
EQU .nu..sub.2 (FP)&gt;.nu..sub.2 (FN) 
when Abbe numbers of the positive and negative lenses in the joining lens 
of the front lens group in the second lens group are respectively set to 
.nu..sub.2 (FP) and .nu..sub.2 (FN). 
When this condition is not satisfied, it is insufficient to correct the 
chromatic aberrations within the second lens group. 
It is also preferable to satisfy the following condition, 
EQU N.sub.2 (FP)&lt;N.sub.2 (FN) 
when refractive indexes of the positive and negative lenses of the above 
joining lens are respectively set to N.sub.2 (FP) and N.sub.2 (FN). 
When this condition is satisfied, it is possible to cause negative 
spherical aberration on a joining face of the above positive and negative 
lenses and correct spherical aberration of the front lens group in the 
second lens group. 
The rear lens group in the second lens group is constructed by positive and 
negative lenses to locate a principal point of the rear lens group on a 
front side thereof on the image side of the second lens group and mainly 
correct chromatic aberration of magnification. It is preferable to satisfy 
the following condition, 
EQU .nu..sub.2 (RN)&gt;.nu..sub.2 (RP) 
when Abbe numbers of the positive and negative lenses constituting the rear 
lens group are respectively set to .nu..sub.2 (RP) and .nu..sub.2 (RN). 
When this condition is not satisfied, it is impossible to correct chromatic 
aberration of magnification in the rear lens group of the second lens 
group. Therefore, the chromatic aberration of magnification of the entire 
lens system caused by a zooming operation of the zoom lens is greatly 
changed. 
In the seventh lens structure of the present invention, the front lens 
group in the second lens group is constructed by sequentially arranging 
two joining lenses composed of a combination of positive and negative 
lenses from the object side of the zoom lens to the image side thereof. 
One of the two joining lens of the front lens group on the object side 
thereof is constructed as a positive lens. The rear lens group in the 
second lens group is constructed by sequentially arranging a positive lens 
and a negative lens from the object side of the zoom lens to the image 
side thereof. 
In the front lens group, the two positive lenses are used to reduce 
aberration easily caused in the front lens group. A first positive lens in 
the front lens group is constructed by the above joining lens composed of 
a combination of positive and negative lenses to correct axial chromatic 
aberration and chromatic aberration of magnification within the second 
lens group. 
Accordingly, it is preferable to satisfy the following condition, 
EQU .nu..sub.2 (FP.sub.1)&gt;.nu..sub.2 (FN.sub.1) 
when Abbe numbers of the positive and negative lenses in the first joining 
lens of the front lens group in the second lens group are respectively set 
to .nu..sub.2 (FP.sub.1) and .nu..sub.2 (FN.sub.1). 
When this condition is not satisfied, it is insufficient to correct the 
chromatic aberrations within the second lens group. 
It is also preferable to satisfy the following condition, 
EQU N.sub.2 (FP.sub.1)&lt;N.sub.2 (FN.sub.1) 
when refractive indexes of the positive and negative lenses of the above 
first joining lens in the front lens group are respectively set to N.sub.2 
(FP.sub.1) and N.sub.2 (FN.sub.1). 
When this condition is satisfied, it is possible to cause negative 
spherical aberration on a joining face of the above positive and negative 
lenses and correct spherical aberration of the front lens group in the 
second lens group. 
It is also preferable to satisfy the following condition, 
EQU N.sub.2 (FP.sub.2)&lt;N.sub.2 (FN.sub.2) 
when refractive indexes of the positive and negative lenses constituting 
the joining lens of the front lens group on an image side thereof in the 
second lens group are respectively set to N.sub.2 (FP.sub.2) and N.sub.2 
(FN.sub.2). 
When this condition is satisfied, it is possible to locate a principal 
point of the front lens group on a front side thereof on the object side 
of the second lens group and correct aberration caused in the positive 
lenses of the front lens group on joining faces of the joining lenses. 
The rear lens group in the second lens group is constructed by positive and 
negative lenses to locate a principal point of the rear lens group on a 
front side thereof on the image side of the second lens group and mainly 
correct chromatic aberration of magnification. 
It is preferable to satisfy the following condition, 
EQU .nu..sub.2 (RN)&gt;.nu..sub.2 (RP) 
when Abbe numbers of the positive and negative lenses constituting the rear 
lens group are respectively set to .nu..sub.2 (RP) and .nu..sub.2 (RN). 
When this condition is not satisfied, it is impossible to correct chromatic 
aberration of magnification in the rear lens group of the second lens 
group. Therefore, the chromatic aberration of magnification of the entire 
lens system caused by a zooming operation of the zoom lens is greatly 
changed. 
In the sixth and seventh lens structures of the present invention, it is 
preferable to use an aspherical lens surface within the front lens group 
of the second lens group so as to correct spherical aberration caused 
within the front lens group of the second lens group. Further, aberration 
outside an optical axis of the lens system can be preferably corrected by 
using an aspherical lens surface within the rear lens group of the second 
lens group. 
In the eighth lens structure of the present invention, the front lens group 
in the second lens group is constructed by sequentially arranging a 
positive lens; a positive lens; and a joining lens composed of a 
combination of negative and positive lenses from the object side of the 
zoom lens to the image side thereof. The rear lens group in the second 
lens group is constructed by sequentially arranging a positive lens and a 
joining lens composed of a combination of negative and positive lenses 
from the object side of the zoom lens to the image side thereof. In the 
front lens group, the two positive lenses are used to reduce an amount of 
aberration caused in the front lens group. The negative lens is arranged 
after these two positive lenses to correct aberration caused by these two 
positive lenses. 
The joining lens in the front lens group is formed by joining a positive 
lens onto an image side of this negative lens to correct axial chromatic 
aberration and chromatic aberration of magnification within the second 
lens group. Accordingly, it is preferable to satisfy the following 
condition, 
EQU .nu..sub.2 (FP)&gt;.nu..sub.2 (FN) 
when Abbe numbers of the positive and negative lenses in the joining lens 
of the front lens group are respectively set to .nu..sub.2 (FP) and 
.nu..sub.2 (FN). When this condition is not satisfied, it is insufficient 
to correct the chromatic aberrations within the second lens group. 
It is also preferable to satisfy the following condition, 
EQU N.sub.2 (FP)&lt;N.sub.2 (FN) 
when refractive indexes of the positive and negative lenses in the above 
joining lens are respectively set to N.sub.2 (FP) and N.sub.2 (FN). 
When this condition is satisfied, a joining face of the above positive and 
negative lenses has negative refracting power so that it is effective to 
correct aberration caused in the positive lenses. A principal point of the 
front lens group on a front side thereof in the second lens group can be 
located on the object side of the second lens group by setting the above 
joining lens to a negative lens. 
In the rear lens group of the second lens group, a positive lens is 
arranged on the most object side of the second lens group and a negative 
lens is arranged on the image side of the second lens group to locate a 
principal point of the rear lens group on a front side thereof on the 
image side of the second lens group. This negative lens is constructed by 
a joining lens composed of a combination of negative and positive lenses 
to mainly correct chromatic aberration of magnification. 
Accordingly, it is preferable to satisfy the following condition, 
EQU .nu..sub.2 (RP)&lt;.nu..sub.2 (RN) 
when Abbe numbers of the positive and negative lenses in this joining lens 
are respectively set to .nu..sub.2 (RP) and .nu..sub.2 (RN). When this 
condition is not satisfied, it is insufficient to correct the chromatic 
aberrations within the second lens group. Therefore, the chromatic 
aberration of magnification of the entire lens system caused at a zooming 
time of the zoom lens is greatly changed. 
In the ninth lens structure of the present invention, the front lens group 
in the second lens group is constructed by sequentially arranging a 
positive lens; a positive lens; and a joining lens composed of a 
combination of negative and positive lenses from the object side of the 
zoom lens to the image side thereof. The rear lens group in the second 
lens group is constructed by sequentially arranging a joining lens 
composed of a combination of positive and negative lenses; and a negative 
lens from the object side of the zoom lens to the image side thereof. 
It is preferable to satisfy the following condition, 
EQU .nu..sub.2 (FP)&gt;.nu..sub.2 (FN) 
when Abbe numbers of the positive and negative lenses in the joining lens 
of the front lens group are respectively set to .nu..sub.2 (FP) and 
.nu..sub.2 (FN). When this condition is not satisfied, it is insufficient 
to correct chromatic aberration within the second lens group. 
It is also preferable to satisfy the following condition, 
EQU N.sub.2 (FP)&lt;N.sub.2 (FN) 
when refractive indexes of the positive and negative lenses in the joining 
lens of the front lens group are respectively set to N.sub.2 (FP) and 
N.sub.2 (FN). When this condition is satisfied, a joining face of the 
above positive and negative lenses has negative refracting power so that 
it is effective to correct aberration caused in the positive lenses. A 
principal point of the front lens group on a front side thereof in the 
second lens group can be located on the object side of the second lens 
group by setting the above joining lens to a negative lens. 
In the rear lens group of the second lens group, a joining lens composed of 
a combination of positive and negative lenses is arranged on the object 
side of the second lens group, i.e., on the front lens group side thereof, 
and a negative lens is arranged on the image side of the second lens group 
to locate a principal point of the rear lens group on a front side thereof 
on the image side of the second lens group and mainly correct chromatic 
aberration of magnification. 
It is preferable to satisfy the following condition, 
EQU .nu..sub.2 (RP)&lt;.nu..sub.2 (RN) 
when Abbe numbers of the positive and negative lenses in the joining lens 
of the rear lens group are respectively set to .nu..sub.2 (RP) and 
.nu..sub.2 (RN). When this condition is not satisfied, it is insufficient 
to correct chromatic aberration within the second lens group. Therefore, 
the chromatic aberration of magnification of the entire lens system caused 
at a zooming time of the zoom lens is greatly changed. 
In the tenth lens structure of the present invention, the front lens group 
in the second lens group is constructed by sequentially arranging a 
joining lens composed of a combination of positive and negative lenses; a 
positive lens; and a joining lens composed of a combination of negative 
and positive lenses from the object side of the zoom lens to the image 
side thereof. The joining lens of the front lens group on the most object 
side thereof is constructed as a positive lens. The rear lens group in the 
second lens group is constructed by sequentially arranging a joining lens 
composed of a combination of positive and negative lenses; and a negative 
lens from the object side of the zoom lens to the image side thereof. 
In the front lens group, the first joining lens and the subsequent positive 
lens are used to reduce an amount of aberration caused in the front lens 
group. The first positive lens is constructed by the joining lens composed 
of positive and negative lenses to correct aberration caused in the 
positive lenses within the second lens group. 
It is preferable to satisfy the following conditions, 
EQU N.sub.2 (FP1)&lt;N.sub.2 (FN1),.nu..sub.2 (FP1)&gt;.nu..sub.2 (FN1) 
when a refractive index and an Abbe number of the positive lens in the 
first joining lens are respectively set to N.sub.2 (FP1) and .nu..sub.2 
(FP1) and a refractive index and an Abbe number of the negative lens in 
this first joining lens are respectively set to N.sub.2 (FN1) and 
.nu..sub.2 (FN1). When these conditions are not satisfied, it is difficult 
to correct aberration within the second lens group. 
A negative lens is arranged after the above first joining lens and the 
positive lens to correct aberration caused by the positive lens. Further, 
a positive lens is joined to this negative lens so as to correct axial 
chromatic aberration and chromatic aberration of magnification within the 
second lens group. Accordingly, it is preferable to satisfy the following 
condition, 
EQU .nu..sub.2 (FP.sub.2)&gt;.nu..sub.2 (FN.sub.2) 
when Abbe numbers of the positive and negative lenses in the final joining 
lens of the front lens group are respectively set to .nu..sub.2 (FP.sub.2) 
and .nu..sub.2 (FN.sub.2). When this condition is not satisfied, it is 
insufficient to correct chromatic aberration within the second lens group. 
It is also preferable to satisfy the following condition, 
EQU N.sub.2 (FP.sub.2)&lt;N.sub.2 (FN.sub.2) 
when refractive indexes of the positive and negative lenses in the final 
joining lens of the front lens group are respectively set to N.sub.2 
(FP.sub.2) and N.sub.2 (FN.sub.2). When this condition is satisfied, a 
joining face of the above positive and negative lenses has negative 
refracting power so that it is effective to correct aberration caused in 
the positive lens. A principal point of the front lens group on a front 
side thereof in the second lens group can be located on the object side of 
the second lens group by setting the above final joining lens to a 
negative lens. 
The rear lens group of the second lens group has the same lens construction 
as the rear lens group of the second lens group in the ninth structure of 
the zoom lens having a high variable magnification. Accordingly, similar 
to the ninth lens structure of the present invention, it is preferable to 
satisfy the following condition, 
EQU .nu..sub.2 (RP)&lt;.nu..sub.2 (RN) 
when Abbe numbers of the positive and negative lenses in the joining lens 
of the rear lens group are respectively set to .nu..sub.2 (RP) and 
.nu..sub.2 (RN). When this condition is not satisfied, it is insufficient 
to correct chromatic aberration within the second lens group. Therefore, 
the chromatic aberration of magnification of the entire lens system caused 
at a zooming time of the zoom lens is greatly changed. 
In the eleventh lens structure of the present invention, the front lens 
group in the second lens group is constructed by sequentially arranging a 
positive lens; a joining lens composed of a combination of positive and 
negative lenses; and a joining lens composed of a combination of negative 
and positive lenses from the object side of the zoom lens to the image 
side thereof. The rear lens group in the second lens group is constructed 
by sequentially arranging a joining lens composed of a combination of 
positive and negative lenses; and a negative lens from the object side of 
the zoom lens to the image side thereof. 
The joining lens constituting a second lens of the front lens group is 
constructed as a positive lens. In the front lens group, this joining lens 
as a positive lens is arranged after the positive lens as a first lens of 
the front lens group to reduce an amount of aberration caused in the front 
lens group. Further, aberration caused in the positive lenses within the 
second lens group is corrected by constructing the second positive lens by 
the joining lens composed of positive and negative lenses to correct. 
It is preferable to satisfy the following conditions, 
EQU N.sub.2 (FP.sub.1)&lt;N.sub.2 (FN.sub.1), .nu..sub.2 (FP.sub.1)&gt;.nu..sub.2 
(FN.sub.1) 
when a refractive index and an Abbe number of the positive lens in the 
first joining lens of the front lens group are respectively set to N.sub.2 
(FP.sub.1) and .nu..sub.2 (FP.sub.1) and a refractive index and an Abbe 
number of the negative lens in this joining lens are respectively set to 
N.sub.2 (FN.sub.1) and .nu..sub.2 (FN.sub.1). When these conditions are 
not satisfied, it is difficult to correct aberration within the second 
lens group. 
A negative lens is arranged after the above positive lens and the above 
first joining lens to correct aberration caused by the positive lenses. 
Further, a positive lens is joined to this negative lens so as to correct 
axial chromatic aberration and chromatic aberration of magnification 
within the second lens group. 
Accordingly, it is preferable to satisfy the following condition, 
EQU .nu..sub.2 (FP.sub.2)&gt;.nu..sub.2 (FN.sub.2) 
when Abbe numbers of the positive and negative lenses in the final joining 
lens of the front lens group are respectively set to .nu..sub.2 (FP.sub.2) 
and .nu..sub.2 (FN.sub.2). When this condition is not satisfied, it is 
insufficient to correct the chromatic aberrations within the second lens 
group. 
It is also preferable to satisfy the following condition, 
EQU N.sub.2 (FP.sub.2)&lt;N.sub.2 (FN.sub.2) 
when refractive indexes of the positive and negative lenses in the final 
joining lens of the front lens group are respectively set to N.sub.2 
(FP.sub.2) and N.sub.2 (FN.sub.2). When this condition is satisfied, a 
joining face of the above positive and negative lenses has negative 
refracting power so that it is effective to correct aberration caused in 
the positive lens. A principal point of the front lens group on a front 
side thereof in the second lens group can be located on the object side of 
the second lens group by setting the above final joining lens to a 
negative lens. 
The rear lens group of the second lens group has the same lens construction 
as the rear lens group of the second lens group in the ninth structure of 
the zoom lens having a high variable magnification. Accordingly, similar 
to the ninth lens structure of the present invention, it is preferable to 
satisfy the following condition, 
EQU .nu..sub.2 (RP)&lt;.nu..sub.2 (RN) 
when Abbe numbers of the positive and negative lenses in the joining lens 
of the rear lens group are respectively set to .nu..sub.2 (RP) and 
.nu..sub.2 (RN). When this condition is not satisfied, it is insufficient 
to correct chromatic aberration within the second lens group. Therefore, 
the chromatic aberration of magnification of the entire lens system caused 
at a zooming time of the zoom lens is greatly changed. 
In the eighth to eleventh lens structures of the present invention, it is 
desirable to use an aspherical lens surface within the second lens group 
so as to correct spherical aberration caused within the front lens group 
of the second lens group. Further, aberration outside an optical axis of 
the lens system can be corrected by using an aspherical lens surface 
within the rear lens group of the second lens group. 
In the twelfth lens structure of the present invention, the front lens 
group in the second lens group is constructed by sequentially arranging a 
joining lens composed of a combination of positive and negative lenses; 
and a joining lens composed of a combination of positive and negative 
lenses from the object side of the zoom lens to the image side thereof. 
The rear lens group in the second lens group is constructed by 
sequentially arranging a joining lens composed of a combination of 
positive and negative lenses; and a negative lens from the object side of 
the zoom lens to the image side thereof. 
In the front lens group, the two positive lenses are used to reduce an 
amount of aberration tending to be greatly caused in the front lens group. 
It is preferable to satisfy the following condition, 
EQU N.sub.2 (FP.sub.2)&lt;N.sub.2 (FN.sub.2) 
when a refractive index of the positive lens in the second joining lens of 
the front lens group is set to N.sub.2 (FP.sub.2) and a refractive index 
of the negative lens in this joining lens is set to N.sub.2 (FN.sub.2). 
When this condition is satisfied, a principal point of the front lens 
group on a front side thereof in the second lens group can be located on 
the object side of the second lens group and aberration caused in the 
above positive lens can be corrected on a joining face of the second 
joining lens. 
A lens of the front lens group on an object side thereof in the second lens 
group is constructed by a positive joining lens composed of a combination 
of positive and negative lenses to correct axial chromatic aberration and 
chromatic aberration of magnification within the second lens group. 
Accordingly, it is preferable to satisfy the following condition, 
EQU .nu..sub.2 (FP.sub.1)&gt;.nu..sub.2 (FN.sub.1) 
when Abbe numbers of the positive and negative lenses in this positive 
joining lens of the front lens group are respectively set to .nu..sub.2 
(FP.sub.1) and .nu..sub.2 (FN.sub.1). When this condition is not 
satisfied, it is insufficient to correct the chromatic aberrations within 
the second lens group. 
It is also preferable to satisfy the following condition, 
EQU N.sub.2 (FP.sub.1)&lt;N.sub.2 (FN.sub.1) 
when refractive indexes of the positive and negative lenses in the above 
positive joining lens of the front lens group on the object side thereof 
in the second lens group are respectively set to N.sub.2 (FP.sub.1) and 
N.sub.2 (FN.sub.1). When this condition is satisfied, negative spherical 
aberration is caused on a joining face of the positive and negative lenses 
of this positive joining lens. Accordingly, it is possible to correct 
spherical aberration of the front lens group in the second lens group. 
In the rear lens group of the second lens group, a joining lens composed of 
a combination of positive and negative lenses, and a negative lens are 
sequentially arranged from the object side of the zoom lens to the image 
side thereof to locate a principal point of the rear lens group on a front 
side thereof on the image side of the second lens group and mainly correct 
chromatic aberration of magnification. 
It is preferable to satisfy the following condition, 
EQU .nu..sub.2 (RN)&gt;.nu..sub.2 (RP) 
when Abbe numbers of the positive and negative lenses constituting the 
above joining lens of the rear lens group are respectively set to 
.nu..sub.2 (RP) and .nu..sub.2 (RN). When this condition is not satisfied, 
it is impossible to correct chromatic aberration of magnification in the 
rear lens group of the second lens group. Therefore, the chromatic 
aberration of magnification of the entire lens system caused by a zooming 
operation of the zoom lens is greatly changed. 
In the thirteenth lens structure of the present invention, the front lens 
group in the second lens group is constructed by sequentially arranging a 
positive lens; a positive lens; and a joining lens composed of a 
combination of negative and positive lenses from the object side of the 
zoom lens to the image side thereof. The rear lens group in the second 
lens group is constructed by sequentially arranging a joining lens 
composed of a combination of positive and negative lenses; and a joining 
lens composed of a combination of negative and positive lenses from the 
object side of the zoom lens to the image side thereof. In the front lens 
group, the two positive lenses are used to reduce an amount of aberration 
tending to be greatly caused in the front lens group. Further, a negative 
lens is arranged after these two positive lenses to correct aberration 
caused in these two positive lenses. Further, a positive lens is joined to 
this negative lens so as to correct axial chromatic aberration and 
chromatic aberration of magnification within the second lens group. 
Accordingly, it is preferable to satisfy the following condition, 
EQU .nu..sub.2 (FP)&gt;.nu..sub.2 (FN) 
when Abbe numbers of the positive and negative lenses in the joining lens 
of the front lens group in the second lens group are respectively set to 
.nu..sub.2 (FP) and .nu..sub.2 (FN). When this condition is not satisfied, 
it is insufficient to correct the chromatic aberrations within the second 
lens group. 
It is also preferable to satisfy the following condition, 
EQU N.sub.2 (FP)&lt;N.sub.2 (FN) 
when refractive indexes of the positive and negative lenses in the above 
joining lens of the front lens group are respectively set to N.sub.2 (FP) 
and N.sub.2 (FN). When this condition is satisfied, a joining face of the 
above negative and positive lenses has negative refracting power so that 
it is effective to correct aberration caused in the positive lenses. 
Further, a principal point of the front lens group on a front side thereof 
in the second lens group can be located on the object side of the second 
lens group by constituting the above joining lens as a negative lens. 
In the rear lens group of the second lens group, a joining lens composed of 
a combination of positive and negative lenses, and a joining lens composed 
of a combination of negative and positive lenses are sequentially arranged 
from the object side of the zoom lens to the image side thereof to locate 
a principal point of the rear lens group on a front side thereof on the 
image side of the second lens group and mainly correct chromatic 
aberration of magnification. 
It is preferable to satisfy the following conditions, 
EQU .nu..sub.2 (RP.sub.1)&lt;.nu..sub.2 (RN.sub.1), .nu..sub.2 
(RN.sub.2)&gt;.nu..sub.2 (RP.sub.2) 
when Abbe numbers of the positive, negative, negative and positive lenses 
sequentially arranged on the object side of the zoom lens and constituting 
the rear lens group are respectively set to .nu..sub.2 (RP.sub.1), 
.nu..sub.2 (RN.sub.1), .nu..sub.2 (RN.sub.2) and .nu..sub.2 (RP.sub.2). 
When these conditions are not satisfied, it is impossible to correct 
chromatic aberration of magnification in the rear lens group of the second 
lens group. Therefore, the chromatic aberration of magnification of the 
entire lens system caused by a zooming operation of the zoom lens is 
greatly changed. 
It is also preferable to satisfy the following condition, 
EQU N.sub.2 (RP.sub.1)&lt;N.sub.2 (RN.sub.1) 
when refractive indexes of the positive and negative lenses in the joining 
lens of the rear lens group on the object side thereof are respectively 
set to N.sub.2 (RP.sub.1) and N.sub.2 (RN.sub.1). When this condition is 
not satisfied, spherical aberration cannot be corrected on a joining face 
of these positive and negative lenses. Accordingly, it is difficult to 
correct spherical aberration of the entire lens system and suitably hold a 
Petzval's sum. 
In the twelfth and thirteenth lens structures of the present invention, it 
is desirable to use an aspherical lens surface within the front lens group 
of the second lens group so as to correct spherical aberration caused 
within the front lens group of the second lens group. Further, aberration 
outside an optical axis of the lens system can be corrected by using an 
aspherical lens surface within the rear lens group of the second lens 
group. 
In the fourteenth lens structure of the present invention, as shown in FIG. 
2, a diaphragm II(S) is arranged between front and rear lens groups in a 
second lens group II. A moving amount of this diaphragm II(S) is set to be 
smaller than that of the second lens group when the zooming operation of a 
zoom lens is performed from a wide angle end of the zoom lens to a 
telescopic end thereof. 
In such a zoom lens having two groups of negative and positive lenses, an 
F-number of the zoom lens is gradually increased while the zooming 
operation is performed from the wide angle end of the zoom lens to the 
telescopic end thereof. Accordingly, it is necessary to extremely reduce 
the F-number of the zoom lens at the wide angle end thereof to reduce the 
F-number and increase brightness at the telescopic end of the zoom lens. 
Therefore, it is difficult to obtain a preferable performance of the zoom 
lens at the wide angle end thereof. 
To solve this problem, in the fourteenth lens structure of the present 
invention, the diaphragm II(S) is arranged between the front and rear lens 
groups of the second lens group II as mentioned above. Further, a moving 
amount of the diaphragm II(S) is set to be smaller than that of the second 
lens group II when the zooming operation is performed from the wide angle 
end of the zoom lens to the telescopic end thereof. 
In such a structure, it is possible to locate the diaphragm II(S) in the 
vicinity of the front lens group of the second lens group at the wide 
angle end of the zoom lens. Further, it is possible to locate the 
diaphragm II(S) in the vicinity of the rear lens group of the second lens 
group at the telescopic end of the zoom lens. In other words, the 
diaphragm II(S) is gradually moved from the front lens group II(F) of the 
second lens group to the rear lens group II(R) thereof while the zooming 
operation is performed from the wide angle end of the zoom lens to the 
telescopic end thereof. Thus, the difference in F-number between the wide 
angle and telescopic ends of the zoom lens can be reduced in comparison 
with that in a case in which a moving amount of the diaphragm is equal to 
that of the second lens group. Accordingly, it is possible to prevent the 
F-number at the telescopic end of the zoom lens from being extremely 
increased while the performance of the zoom lens at the wide angle end 
thereof is preferably held. 
The diameter of the first lens group can be held small by the above 
arrangement of the diaphragm. Further, the performance of the zoom lens 
can be improved since an upper light beam can be interrupted on the 
telescopic side of the zoom lens. Further, it is possible to reduce a 
diameter of the diaphragm by the above arrangement. 
When the arrangement of the diaphragm in the fourteenth lens structure of 
the present invention is used, it is preferable to construct the second 
lens group in accordance with the above fifteenth to eighteenth lens 
structures of the present invention. 
In the zoom lens constructed by two groups of negative and positive lenses, 
the relation in position between the first and second lens groups is 
greatly changed in the zooming operation of the zoom lens. Accordingly, it 
is ideal to preferably correct aberrations by each of the first and second 
lens groups until a maximum field angle of the zoom lens. Further, it is 
ideal to reduce a change in aberration of the entire lens system at a 
zooming time thereof so as to provide a preferable performance of the zoom 
lens in an entire zooming region thereof. 
However, it is very difficult to preferably correct the above aberrations 
and provide the preferable performance of the zoom lens. Normally, the 
performance of the zoom lens is preferably held by balancing changes in 
aberration of the entire lens system caused by residual aberrations of the 
respective lens groups in the entire zooming region of the zoom lens at 
the zooming time thereof. 
In this case, there is a case in which the position of a best peripheral 
image surface is not in conformity with the position of a best central 
image surface. When there is such nonconformity, the performance of the 
zoom lens is greatly reduced by errors in processing, assembly and 
focusing of the zoom lens, etc. 
In the nineteenth lens structure of the present invention, the distance 
between the front and rear lens groups in the second lens group is changed 
in accordance with the zooming operation of the zoom lens. The distance 
between the front and rear lens groups is reduced in an intermediate 
zooming region of the zoom lens. 
When the zooming operation is performed by integrally moving the front and 
rear lens groups in the second lens group, the position of a best 
peripheral image surface is separated from a lens at the distance of a 
best central image surface at an intermediate focal length of the zoom 
lens. In the nineteenth lens structure of the present invention, the 
distance between the front and rear lens groups in the second lens group 
is slightly reduced in the intermediate zooming region of the zoom lens so 
as to correct the above separation of the best peripheral image surface 
from the lens. 
In general, when a diaphragm is arranged within the front lens group of the 
second lens group or on an object side of the front lens group, a most 
peripheral light beam at the wide angle end of the zoom lens is not 
restricted by an opening diameter of the diaphragm, but is restricted by 
effective diameters of lenses before and after the diaphragm, or an 
opening diameter of a light-interrupting member. 
Accordingly, when the zooming operation is performed from the wide angle 
end of the zoom lens to the telescopic end thereof, the distance between 
the first and second lens groups is reduced and a field angle of the zoom 
lens is reduced. Therefore, the size of a peripheral light beam on a 
diaphragm face is increased and a vigetting factor of the zoom lens is 
increased so that a quantity of the peripheral light beam is considerably 
increased. 
In general, it is difficult to sufficiently correct aberration with respect 
to a marginal portion of the light beam so that flare light is often 
caused and prevents an image forming performance of the zoom lens. 
Accordingly, it is desirable to secure a necessary and sufficient 
peripheral light quantity and interrupt a marginal portion of the light 
beam except for this peripheral light as much as possible. 
As mentioned above, the peripheral light quantity is considerably increased 
when the zooming operation is performed from the wide angle end of the 
zoom lens to the telescopic end thereof. Accordingly, it is possible to 
secure the necessary and sufficient peripheral light quantity even when 
flare light is interrupted in the marginal portion of the light beam. 
In the twentieth lens structure of the present invention, a first diaphragm 
is disposed within the front lens group of the second lens group or on an 
object side of the front lens group. A second diaphragm having a constant 
opening diameter is disposed between the front and rear lens groups. When 
the zooming operation is performed from the wide angle end of the zoom 
lens to the telescopic end thereof, the second diaphragm is moved such 
that the second diaphragm is separated from the front lens group of the 
second lens group. Thus, a large amount of a most peripheral light beam is 
transmitted through the zoom lens at the wide angle end thereof at which 
the quantity of peripheral light is small. Further, flare light is 
interrupted at the telescopic end of the zoom lens at which the quantity 
of peripheral light is not small. 
A focusing system for moving the first lens group is generally used in the 
above zoom lens having two groups of negative and positive lenses. In such 
a focusing system, a moving amount of the first lens group in a focusing 
operation of the zoom lens is approximately constant at the same distance 
from the zoom lens to a photographed object in a front zooming region of 
the zoom lens. Accordingly, no special focusing mechanism is required in 
this focusing system. However, in this focusing system, a movable lens 
group is disposed on the most photographed object side of the zoom lens. 
Therefore, it is necessary to dispose a mechanism for moving this movable 
lens group in the case of an automatic focusing camera so that the zoom 
lens is large-sized. 
The twenty-first lens structure of the present invention uses a focusing 
system for moving the rear lens group in the second lens group. In the 
following description, reference numeral .DELTA.X designates a moving 
amount of the rear lens group of the second lens group in a focusing 
operation of the zoom lens. This moving amount .DELTA.X can be represented 
by the following formula when this moving amount is small. 
EQU .DELTA.X=x.multidot.f.sup.2 /{m.sub.2 (R).sup.2 -1} 
In this formula, reference numeral x designates a distance from a principal 
point of the entire lens system on a front side thereof to the 
photographed object. Reference numeral f designates a focal length of the 
entire lens system. Further, reference numeral m.sub.2 (R) designates a 
lateral magnification of the rear lens group in the second lens group. 
When m.sub.2 (R)&gt;1 is satisfied at any time and the focusing operation is 
performed in a state in which the distance from the zoom lens to the 
photographed object is short, the rear lens group in the second lens group 
is moved on the image side of the second lens group. The moving amount of 
the rear lens group is reduced as the lateral magnification m.sub.2 (R) is 
increased. The lateral magnification m.sub.2 (R) is represented by the 
following formula. 
EQU m.sub.2 (R)=1-{BF/f.sub.2 (R)} 
In this formula, reference numeral BF designates a distance from a 
principal point of the rear lens group on a rear side thereof in the 
second lens group to an image face. 
From this formula, it is understood that the lateral magnification m.sub.2 
(R) is increased as the distance BF is increased and the absolute focal 
length .vertline.f.sub.2 (R).vertline. is reduced. 
In the above twenty-first lens structure of the present invention, a back 
focus of the zoom lens is smallest at the wide angle end thereof. 
Accordingly, when the moving amount of the rear lens group in the focusing 
operation of the zoom lens is increased, the rear lens group in the second 
lens group excessively approaches the image face and the diameter of the 
rear lens group is increased. Further, a change in aberration of the rear 
lens group is increased and the performance of the zoom lens is 
deteriorated at a focusing time thereof. Accordingly, it is necessary to 
increase the lateral magnification m.sub.2 (R) and reduce the moving 
amount of the rear lens group in the focusing operation of the zoom lens. 
As mentioned above, it is necessary to reduce the absolute focal length 
.vertline.f.sub.2 (R).vertline. to increase the lateral magnification 
m.sub.2 (R). However, when this absolute focal length is excessively 
reduced, it is difficult to correct aberration in the rear lens group of 
the second lens group. 
Therefore, in the twenty-first lens structure of the present invention, the 
rear lens group in the second lens group has at least one positive lens. 
In the following description, reference numeral m.sub.2 (RW) designates a 
lateral magnification of the rear lens group in the second lens group at 
the wide angle end of the zoom lens and infinity with respect to the 
photographed object. In the twenty-first lens structure of the present 
invention, this lateral magnification m.sub.2 (RW) satisfies the following 
condition. 
EQU 1. 1&lt;m.sub.2 (RW)&lt;2 
When the lateral magnification m.sub.2 (RW) exceeds a lower limit thereof 
in the above condition, the moving amount of the rear lens group in the 
second lens group is excessively increased, thereby causing the 
above-mentioned problems. In contrast to this, when the lateral 
magnification m.sub.2 (RW) exceeds an upper limit thereof in the above 
condition, a focal length of the rear lens group in the second lens group 
is excessively shortened so that it is difficult to correct aberration in 
the rear lens group. 
The distance between the front and rear lens groups in the second lens 
group is changed by the focusing operation of the zoom lens. Accordingly, 
it is necessary to independently correct aberration with respect to each 
of the front and rear lens groups of the second lens group so as to 
preferably hold the performance of the zoom lens at the focusing time 
thereof, etc. Accordingly, at least one positive lens is arranged in the 
rear lens group of the second lens group to correct aberration caused in a 
negative lens. 
It is necessary to dispose at least one negative lens to correct aberration 
in the front lens group of the second lens group. Further, it is 
preferable to arrange a positive lens as a final lens in the front lens 
group of the second lens group to preferably correct the aberration of the 
front lens group. 
In the zoom lens having two groups of negative and positive lenses, when 
the zooming operation is performed from the wide angle end of the zoom 
lens to the telescopic end thereof, an F-number of the zoom lens at the 
telescopic end thereof is larger than that at the wide angle end of the 
zoom lens. When the F-number is reduced at the telescopic end of the zoom 
lens to increase brightness thereof, it is necessary to extremely reduce 
the F-number of the zoom lens at the wide angle end thereof. In this case, 
it is difficult to secure a preferable performance of the zoom lens at the 
wide angle end thereof. 
To solve this problem, in the twenty-second lens structure of the present 
invention, a diaphragm is arranged between the front and rear lens groups 
in the second lens group. When the zooming operation is performed from the 
wide angle end of the zoom lens to the telescopic end thereof, a moving 
amount of this diaphragm is set to be smaller than that of the second lens 
group. Thus, this diaphragm within the second lens group approaches the 
front lens group of the second lens group at the wide angle end of the 
zoom lens and approaches the rear lens group of the second lens group at 
the telescopic end of the zoom lens. Therefore, it is possible to reduce 
the difference in F-number between the wide angle and telescopic ends of 
the zoom lens. Further, it is possible to preferably hold the performance 
of the zoom lens at the wide angle end thereof. The diameter of the first 
lens group can be held small by the above arrangement of the diaphragm and 
a marginal portion of the light beam can be interrupted at the telescopic 
end of the zoom lens, thereby providing a preferable performance of the 
zoom lens. 
Concrete Embodiments of the present invention will next be described. 
In the respective concrete Embodiments, reference numeral Ri using suffix i 
designates a radius of curvature of an i-th face (including a diaphragm) 
counted from the object side of the zoom lens. Reference numeral Di using 
suffix i designates a distance between an i-th face and an (i+1)-th face 
on an optical axis of the lens system. Reference numerals Nj and .nu.j 
using suffix j respectively designate a refractive index and an Abbe 
number of a j-th lens counted from the object side of the zoom lens with 
respect to line d. 
Further, reference numeral f designates a combined focal length of the 
entire lens system. Reference numerals .omega. and FNo respectively 
designate a field angle (unit: degree) and brightness. 
In the following description, reference numeral Y designates a coordinate 
in a direction perpendicular to the optical axis of the lens system. 
Reference numeral Z designates a coordinate in the direction of the 
optical axis of the lens system. Reference numeral R designates a radius 
of curvature on the optical axis of the lens system. Further, reference 
numeral K designates a conical constant and reference numerals A, B, C and 
D respectively designate aspherical coefficients of fourth, sixth, eighth 
and tenth orders. In this case, as is well known, an aspherical surface is 
a curved surface formed by rotating a curve represented by the following 
formula using the above parameters, 
EQU Z={(1/R).multidot.Y.sup.2 
/[1+.sqroot.{1-(1+K).multidot.(1/R.sup.2).multidot.Y.sup.2 
}]}+A.multidot.Y.sup.4 +B.multidot.Y.sup.6 +C.multidot.Y.sup.8 
+D.multidot.Y.sup.10 
around the optical axis of the lens system. This aspherical surface is 
determined by specifying the above parameters R, K, A, B, C and D. The 
above radius Ri of curvature shows a radius of curvature on the optical 
axis of the lens system with respect to the aspherical surface. Alphabet E 
and a number subsequent to this alphabet E show power with respect to the 
aspherical coefficients of higher orders about the aspherical surface. For 
example, E-10 means 1/10.sup.10 and a number before this alphabet E is 
multiplied by this value 1/10.sup.10. 
______________________________________ 
Embodiment 1 
F36.5.about.102, FNo. = 3.12.about.6.33, .omega. = 63.0.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -132.697 0.811 1 1.88300 
40.80 
2 29.272 2.023 
3 32.595 3.738 2 1.82359 
24.52 
4 134.613 variable 
5 18.131 6.338 3 1.62203 
61.38 
6 -38.166 0.800 4 1.87092 
33.66 
7 -334.457 0.715 
8 .infin.(diaphragm) 
1.000 
9 18.398 3.952 5 1.49700 
81.60 
10 531.439 2.276 
11 -76.803 0.800 6 1.87296 
34.25 
12 13.536 0.351 
13 15.229 8.987 7 1.58735 
39.47 
14 -13.045 0.800 8 1.75325 
52.38 
15 -40.214 15.384 
16 -13.021 0.800 9 1.49700 
81.60 
17 227.475 3.068 10 1.64854 
32.88 
18 -59.992 
Aspherical surfaces 
Fifth face 
K = -0.060693, A = -1.747204E-6, 
B = -1.219325E-8, C = 1.161183E-10, 
D = -1.720309E-14 
Eleventh face 
K = 16.956051, A = -4.631422E-6, 
B = 9.861092E-9, C = 6.670963E-10, 
D = -1.069999E-11 
Fifteenth face 
K = -2.763672, A = 2.439264E-6, 
B = 4.534996E-8, C = 1.219346E-9, 
D = -2.231143E-11 
Sixteenth face 
K = -0.046230, A = 1.114557E-5, 
B = 2.040012E-7, C = -1.691015E-9, 
D = 9.442470E-12 
Variable amounts 
f 36.496 61.009 101.985 
D.sub.4 
30.170 12.415 1.795 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.509 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.509 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.313, f.sub.2 (F)/f.sub.2 
= 1.120, 
.vertline.f.sub.1 .vertline./.sqroot.[f(W) .multidot. f(T)] = 1.000 
Embodiment 2 
F36.5.about.102, FNO. = 2.94.about.5.93, .omega. = 63.7.about.23.7 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -104.634 0.901 1 1.88300 
40.80 
2 30.331 1.302 
3 32.705 4.127 2 1.84666 
23.83 
4 155.989 variable 
5 21.215 6.017 3 1.61765 
55.16 
6 -24.053 1.450 4 1.83400 
37.34 
7 -105.946 0.855 
8 .infin.(diaphragm) 
0.868 
9 22.286 3.794 5 1.49700 
81.60 
10 -73.311 2.077 
11 -45.160 2.481 6 1.90315 
29.84 
12 15.975 0.488 
13 17.177 6.581 7 1.62004 
36.30 
14 -12.539 0.859 8 1.77250 
49.62 
15 -31.745 20.308 
16 -10.904 0.824 9 1.49700 
81.61 
17 -73.312 2.064 10 1.84666 
23.83 
18 -38.005 
Aspherical surfaces 
Fifth face 
K = -0.035077, A = -5.228067E-7, 
B = -3.877944E-9, C = 1.169510E-10, 
D = 1.640908E-14 
Sixteenth face 
K = -0.300459, A = 5.721353E-6, 
B = 7.199471E-8, C = 6.221942E-10, 
D = -4.087988E-12 
Variable amounts 
f 36.505 60.012 102.032 
D.sub.4 
29.189 11.825 0.719 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)} 
]/f(T) = 0.5 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.495 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.243, f.sub.2 (F)/f.sub.2 
= 1.160, 
.vertline.f.sub.1 .vertline./.sqroot.[f(W) .multidot. f(T)] = 1.008 
Embodiment 3 
F36.5.about.102, FNO. = 2.87.about.5.82, .omega. = 63.8.about.23.4 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -69.698 0.800 1 1.88300 
40.80 
2 37.077 0.928 
3 39.268 3.589 2 1.84666 
23.83 
4 467.492 variable 
5 21.197 6.600 3 1.63854 
55.45 
6 -31.186 0.800 4 1.83400 
37.34 
7 -177.850 1.478 
8 .infin.(diaphragm) 
1.685 
9 18.309 3.731 5 1.49700 
81.60 
10 -75.042 1.184 
11 -40.565 0.888 6 1.85030 
32.18 
12 14.872 0.100 
13 14.646 10.000 7 1.59551 
39.22 
14 -12.062 1.435 8 1.81600 
46.57 
15 -23.162 11.152 
16 -12.511 6.131 9 1.75500 
52.32 
17 -76.754 3.756 10 1.84666 
23.83 
18 -85.092 
Aspherical surfaces 
Ninth face 
K = -0.179177, A = -3.612813E-6, 
= 3.874821E-9, C = 2.971765E-10, 
= 1.767060E-12 
Eighteenth face 
K = -0.718998, A = -1.850240E-6, 
B = -3.234995E-8, C = 3.320808E-10, 
D = -6.586454E-13 
Variable amounts 
f 36.496 59.992 101.979 
D.sub.4 
28.852 11.826 0.938 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.468 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.46 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 0.828, f.sub.2 (F)/f.sub.2 
= 1.033, 
.vertline.f.sub.1 .vertline./.sqroot.[f(W) .multidot. f(T)] = 1.016 
______________________________________ 
The above Embodiments 1 to 3 relate to the second lens structure of the 
present invention. 
FIG. 3 shows a lens arrangement in the Embodiment 1 at the wide angle end 
of the zoom lens. FIGS. 6, 7 and 8 respectively show aberration diagrams 
with respect to the Embodiment 1 at the wide angle end of the zoom lens, 
an intermediate focal length of the zoom lens and the telescopic end of 
the zoom lens. 
FIG. 4 shows a lens arrangement in the Embodiment 2 at the wide angle end 
of the zoom lens. FIGS. 9, 10 and 11 respectively show aberration diagrams 
with respect to the Embodiment 2 at the wide angle end of the zoom lens, 
an intermediate focal length of the zoom lens and the telescopic end of 
the zoom lens. 
FIG. 5 shows a lens arrangement in the Embodiment 3 at the wide angle end 
of the zoom lens. FIGS. 12, 13 and 14 respectively show aberration 
diagrams with respect to the Embodiment 3 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
In the respective aberration diagrams, reference numerals dSA and gSA 
respectively designate spherical aberrations with respect to lines d and 
g. Reference numeral SC designates a sine condition. Further, reference 
numerals S and M respectively designate sagittal and meridional image 
surfaces with respect to line d. 
______________________________________ 
Embodiment 4 
f = 36.5.about.102, FNO. = 2.9.about.5.9, .omega. = 63.6.about.23.3 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -67.412 0.815 1 1.86300 
41.53 
2 35.934 0.925 
3 38.182 3.441 2 1.84666 
23.89 
4 366.434 variable 
5 20.555 5.581 3 1.60300 
65.48 
6 -41.043 0.803 4 1.77250 
49.60 
7 -102.177 1.621 
8 .infin.(diaphragm) 
0.800 
9 24.460 3.143 5 1.48749 
70.21 
10 -157.363 0.671 
11 -44.969 0.897 6 1.87400 
35.26 
12 18.177 0.461 
13 18.583 9.994 7 1.52630 
51.17 
14 -24.705 18.060 
15 -15.238 3.090 8 1.75500 
52.33 
16 48.195 4.294 9 1.84666 
23.89 
17 -118.121 
Aspherical surfaces 
Ninth face 
K = -1.008267, A = -1.348746E-5, 
B = -6.190930E-8, C = -1.977751E-10, 
D = -2.773300E-13 
Seventeenth face 
K = 1.285372, A = 5.394611E-7, 
B = -4.647639E-8, C = 4.028286E-10, 
D = -7.529230E-13 
Variable amounts 
f 36.499 59.997 101.993 
D.sub.4 
28.220 11.568 0.919 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.464 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.463 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 0.900, f.sub.2 (F)/f.sub.2 
= 1.125, 
.vertline.f.sub.1 .vertline..sqroot.[f(W) .multidot. f(T)] = 1.002 
Embodiment 5 
f = 36.5.about.102, FNO. = 2.92.about.5.89, .omega. = 63.6.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -77.786 0.945 1 1.83400 
37.34 
2 29.381 1.237 
3 33.157 3.954 2 1.84666 
23.83 
4 229.379 variable 
5 19.893 5.372 3 1.59181 
58.31 
6 -46.078 0.800 4 1.83500 
42.98 
7 -211.030 0.800 
8 .infin.(diaphragm) 
0.800 
9 23.248 3.218 5 1.48749 
70.44 
10 -128.429 1.178 
11 -60.671 1.095 6 1.83400 
37.34 
12 14.567 0.101 
13 14.697 8.586 7 1.52130 
52.78 
14 -34.238 22.249 
15 -13.852 0.791 8 1.60300 
65.48 
16 135.446 3.440 9 1.84666 
23.83 
17 -77.710 
Aspherical surfaces 
First face 
K = -1.071674, A = 3.221728E-7, 
B = 4.065251E-9, C = -1.096925E-11, 
D = 1.113897E-14 
Ninth face 
K = -0.640719, A = -1.052945E-5, 
B = -4.057532E-8, C = 9.494987E-11, 
D = -9.978813E-13 
Fifteenth face 
K = -0.241523, A = -2.499751E-6, 
B = 1.215630E-7, C = -1.683378E-9, 
D = 3.317575E-12 
Variable amounts 
f 36.500 60.000 101.999 
D.sub.4 
28.514 11.517 0.646 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.484 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.482 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.113, f.sub.2 (F)/f.sub.2 
= 1.168, 
.vertline.f.sub.1 .vertline./.sqroot.[f(W) .multidot. f(T)] = 1.003 
Embodiment 6 
f = 36.5.about.102, FNO. = 2.88.about.5.88, .omega. = 63.6.about.23.4 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -87.110 0.800 1 1.88300 
40.80 
2 33.970 1.781 
3 38.217 3.334 2 1.84700 
23.90 
4 242.958 variable 
5 20.025 5.539 3 1.56743 
67.80 
6 -42.408 0.800 4 1.88300 
40.80 
7 -133.825 1.260 
8 .infin.(diaphragm) 
0.800 
9 22.793 3.373 5 1.49700 
81.60 
10 -106.185 1.692 
11 -57.483 1.800 6 1.88300 
40.80 
12 15.236 0.100 
13 15.335 7.904 7 1.53408 
50.08 
14 -33.771 21.829 
15 -13.078 0.800 8 1.49700 
81.60 
16 106.335 2.938 9 1.84700 
23.90 
17 -187.702 
Aspherical surfaces 
First face 
K = -0.588739, A = 1.293210E-7, 
B = -6.215850E-10, C = 8.351060E-12, 
D = -2.353410E-14 
Ninth face 
K = -0.635545, A = -1.046480E-5, 
B = -5.148540E-8, C = 1.942750E-10, 
D = -1.655200E-12 
Fifteenth face 
K = -0.312535, A = 1.820590E-6, 
B = -9.882400E-8, C = 6.637100E-10, 
D = -4.115400E-12 
Variable amounts 
f 36.502 61.007 102.013 
D.sub.4 
28.251 11.081 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.45 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.469 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.096, f.sub.2 (F)/f.sub.2 
= 1.200, 
.vertline.f.sub.1 .vertline./.sqroot.[f(W) .multidot. f(T)] = 1.002 
______________________________________ 
The above Embodiments 4 to 6 relate to the third lens structure of the 
present invention. 
FIG. 15 shows a lens arrangement in the Embodiment 4 at the wide angle end 
of the zoom lens. FIGS. 18, 19 and 20 respectively show aberration 
diagrams with respect to the Embodiment 4 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 16 shows a lens arrangement in the Embodiment 5 at the wide angle end 
of the zoom lens. FIGS. 21, 22 and 23 respectively show aberration 
diagrams with respect to the Embodiment 5 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 17 shows a lens arrangement in the Embodiment 6 at the wide angle end 
of the zoom lens. FIGS. 24, 25 and 26 respectively show aberration 
diagrams with respect to the Embodiment 6 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
______________________________________ 
Embodiment 7 
f = 36.5.about.102, FNO. = 2.9.about.5.9, .omega. = 63.5.about.23.6 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -85.138 0.887 1 1.83400 
37.34 
2 28.026 0.853 
3 29.944 4.583 2 1.84666 
23.83 
4 169.05 variable 
5 18.918 6.622 3 1.48749 
70.44 
6 -87.255 2.089 
7 .infin.(diaphragm) 
0.800 
8 25.961 3.318 4 1.54814 
45.82 
9 -49.591 0.138 
10 -41.883 0.800 5 1.84666 
23.83 
11 59.536 5.669 
12 .infin. 10.795 
13 137.981 7.042 6 1.68893 
31.16 
14 -13.085 2.279 7 1.88300 
40.80 
15 -84.900 7.786 
16 -12.568 0.800 8 1.49700 
81.61 
17 -36.562 
Aspherical surfaces 
Eighth face 
K = -1.182221, A = -7.870754E-6, 
B = -7.371219E-8, C = 8.003773E-11, 
D = -4.319129E-12 
Sixteenth face 
K = -0.73049, A = -1.862161E-5, 
B = 8.064080E-8, C = -1.216524E-9, 
D = 3.255338E-12 
Variable amounts 
f 36.499 60.998 101.996 
d.sub.4 
29.385 11.372 0.585 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.46 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.435 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.298, f.sub.2 (F)/f.sub.2 
= 1.227, 
.vertline.f.sub.1 .vertline./.sqroot.[f(W) .multidot. f(T)] = 1.047 
Embodiment 8 
f = 36.5.about.102, FNO. = 2.86.about.5.89, .omega. = 63.4.about.23.6 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -83.270 0.800 1 1.88300 
40.80 
2 35.360 1.583 
3 38.701 3.520 2 1.84666 
23.82 
4 238.279 variable 
5 19.134 8.212 3 1.50378 
66.89 
6 -144.780 1.709 
7 .infin.(diaphragm) 
0.800 
8 27.612 5.993 4 1.54072 
47.20 
9 -30.027 0.100 
10 -29.479 0.800 5 1.84666 
23.83 
11 70.640 3.433 
12 .infin. 12.701 
13 61.406 7.707 6 1.69895 
30.05 
14 -14.007 0.800 7 1.88300 
40.80 
15 -206.074 6.418 
16 -12.759 0.800 8 1.49700 
81.61 
17 -41.783 
Aspherical surfaces 
Eighth face 
K = -1.403890, A = -9.278020E-6, 
B = -8.577710E-8, C = 9.345540E-11, 
D = -2.707970E-12 
Sixteenth face 
K = -0.736120, A = -1.815330E-5, 
B = 1.581560E-8, C = -5.265050E-10, 
D = 2.489460E-12 
Variable amounts 
f 36.45 60.999 101.996 
D.sub.4 
27.625 10.847 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.443 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.441 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.423, f.sub.2 (F)/f.sub.2 
= 1.286, 
.vertline.f.sub.1 .vertline. /.sqroot.[f(W) .multidot. f(T)] = 1.004 
Embodiment 9 
f = 36.5.about.102, FNO. = 2.9.about.5.9, .omega. = 63.4.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -83.380 0.800 1 1.88300 
40.80 
2 33.027 1.073 
3 34.906 4.360 2 1.78472 
25.70 
4 647.228 variable 
5 19.178 6.721 3 1.51680 
64.20 
6 -187.184 1.664 
7 .infin.(diaphragm) 
0.800 
8 30.373 3.563 4 1.51742 
52.15 
9 -31.353 0.100 
10 -32.321 0.800 5 1.84666 
23.83 
11 152.357 6.000 
12 .infin. 11.287 
13 276.854 7.042 6 1.69895 
30.05 
14 -11.945 0.800 7 1.88300 
40.80 
15 -86.726 6.101 
16 -11.369 0.800 8 1.49700 
81.61 
17 -31.513 
Aspherical surfaces 
Eighth face 
K = -1.601750, A = -9.927140E-6, 
B = -8.102590E-8, C = 1.170720E-10, 
D = -2.498730E-12 
Sixteenth face 
K = -0.709399, A = -2.297340E-5, 
B = -5.850550E-8, C = -1.521790E-9, 
D = 6.285460E-12 
Variable amounts 
f 36.504 61.03 102.032 
D.sub.4 
30.402 11.879 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.454 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.416 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.072, f.sub.2 (F)/f.sub.2 
= 1.193, 
.vertline.f.sub.1 .vertline./.sqroot.[f(W) .multidot. f(T)] = 1.073 
______________________________________ 
The above Embodiments 7 to 9 relate to the fourth lens structure of the 
present invention. 
FIG. 27 shows a lens arrangement in the Embodiment 7 at the wide angle end 
of the zoom lens. FIGS. 30, 31 and 32 respectively show aberration 
diagrams with respect to the Embodiment 7 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 28 shows a lens arrangement in the Embodiment 8 at the wide angle end 
of the zoom lens. FIGS. 33, 34 and 35 respectively show aberration 
diagrams with respect to the Embodiment 8 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 29 shows a lens arrangement in the Embodiment 9 at the wide angle end 
of the zoom lens. FIGS. 36, 37 and 38 respectively show aberration 
diagrams with respect to the Embodiment 9 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
______________________________________ 
Embodiment 10 
f = 36.5.about.102, FNO. = 2.89.about.5.9, .omega. = 63.3.about.23.6 
i R i D i j N j .nu. j 
______________________________________ 
1 -82.478 1.221 1 1.83400 
37.34 
2 28.647 0.871 
3 30.543 4.510 2 1.84666 
23.83 
4 181.540 variable 
5 19.466 7.648 3 1.51823 
58.96 
6 -93.610 1.537 
7 .infin. (diaphragm) 
0.800 
8 26.409 4.253 4 1.54814 
45.82 
9 -29.127 0.990 5 1.84666 
23.83 
10 56.893 3.949 
11 .infin. 12.653 
12 75.006 7.593 6 1.69895 
30.05 
13 -13.437 1.326 7 1.88300 
40.80 
14 -163.240 6.368 
15 -11.992 0.944 8 1.49700 
81.61 
16 -35.711 
Aspherical surfaces 
Eighth face 
K = -1.068895, A = -7.529721E-6, 
B = -7.581887E-8, C = 1.848291E-10, 
D = -4.184132E-12 
Fifteenth face 
K = -0.720314, A = -2.032129E-5, 
B = 3.981674E-8, C = -1.029337E-9, 
D = 3.613058E-12 
Variable amounts 
f 36.502 61.005 102.010 
D.sub.4 29.183 11.321 0.624 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.44 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.411 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.290, f.sub.2 (F)/f.sub.2 
= 1.255, .vertline.f.sub.1 .vertline./ 
.sqroot.[f(W) .multidot. f(T)] = 1.055 
______________________________________ 
Embodiment 11 
f = 36.5.about.102, FNO. = 2.86.about.5.9, .omega. = 63.3.about.23.6 
i R i D i j N j .nu. j 
______________________________________ 
1 -85.106 0.800 1 1.88300 
40.80 
2 35.156 1.538 
3 38.289 3.528 2 1.84666 
23.83 
4 218.963 variable 
5 19.131 8.962 3 1.51742 
52.15 
6 -110.215 1.351 
7 .infin. (diaphragm) 
0.800 
8 25.705 5.581 4 1.56965 
49.39 
9 -25.120 0.800 5 1.84666 
23.83 
10 47.428 3.919 
11 .infin. 11.932 
12 56.689 7.728 6 1.72825 
28.32 
13 -14.124 0.800 7 1.88300 
40.80 
14 -545.329 6.809 
15 -12.528 0.800 8 1.51728 
69.68 
16 -35.185 
Aspherical surfaces 
Eighth face 
K = -1.086781, A = -7.694750E-6, 
B = -7.990350E-8, C = 1.269480E-10, 
D = -3.567750E-12 
Fifteenth face 
K = -0.718346, A = -2.065820E-5, 
B = 2.539640E-8, C = -7.606460E-10, 
D = 2.968370E-12 
Variable amounts 
f 36.5 61.0 102.0 
D.sub.4 27.651 10.857 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.447 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.446 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.553, f.sub.2 (F)/f.sub.2 
= 1.289, .vertline.f.sub.1 .vertline./ 
.sqroot.[ f(W) .multidot. f(T)] = 1.001 
______________________________________ 
Embodiment 12 
f = 36.5.about.102, FNO. = 2.91.about.5.9, .omega. = 63.3.about.22.5 
i R i D i j N j .nu. j 
______________________________________ 
1 -79.300 0.800 1 1.88300 
40.80 
2 30.882 0.804 
3 32.072 4.692 2 1.76182 
26.55 
4 8312.033 variable 
5 19.371 5.138 3 1.51823 
58.96 
6 -110.256 1.657 
7 .infin. (diaphragm) 
0.800 
8 27.310 3.557 4 1.51602 
56.77 
9 -38.223 0.800 5 1.84666 
23.83 
10 81.350 4.431 
11 .infin. 12.226 
12 175.268 6.711 6 1.69895 
30.05 
13 -11.845 0.800 7 1.88300 
40.80 
14 -93.359 6.106 
15 -10.865 0.800 8 1.49700 
81.61 
16 -29.498 
Aspherical surfaces 
Eighth face 
K = -1.100163, A = -7.715040E-6, 
B = -7.482230E-8, C = 2.277150E-10, 
D = -3.216280E-12 
Fifteenth face 
K = -0.683131, A = -2.921990E-5, 
B = 9.162650E-8, C = -2.548350E-9, 
D = 8.628930E-12 
Variable amounts 
f 36.501 61.004 102.009 
D.sub.4 30.306 11.851 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.457 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.421 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.090, f.sub.2 (F)/f.sub.2 
= 1.172, .vertline.f.sub.1 .vertline./ 
.sqroot.[f(W) .multidot. f(T)] = 1.069 
______________________________________ 
The above Embodiments 10 to 12 relate to the fifth lens structure of the 
present invention. 
FIG. 39 shows a lens arrangement in the Embodiment 10 at the wide angle end 
of the zoom lens. FIGS. 42, 43 and 44 respectively show aberration 
diagrams with respect to the Embodiment 10 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 40 shows a lens arrangement in the Embodiment 11 at the wide angle end 
of the zoom lens. FIGS. 45, 46 and 47 respectively show aberration 
diagrams with respect to the Embodiment 11 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 41 shows a lens arrangement in the Embodiment 12 at the wide angle end 
of the zoom lens. FIGS. 48, 49 and 50 respectively show aberration 
diagrams with respect to the Embodiment 12 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
In the respective Embodiments with respect to the above first to fifth lens 
structures of the present invention, a preferable performance of the zoom 
lens is provided by setting an upper limit of the ratio in the 
above-mentioned condition (III) to be equal to or less than 1.6. 
______________________________________ 
Embodiment 13 
f = 36.5.about.102, FNO. = 2.88.about.5.9, .omega. = 63.7.about.23.6 
i R i D i j N j .nu. j 
______________________________________ 
1 -85.106 0.800 1 1.88300 
40.80 
2 31.315 1.255 
3 33.719 4.060 2 1.80518 
25.46 
4 330.722 variable 
5 16.825 6.246 3 1.51728 
69.68 
6 -57.088 0.800 4 1.84666 
23.83 
7 -157.964 2.681 
8 .infin. (diaphragm) 
0.800 
9 27.315 11.821 5 1.48749 
70.44 
10 -15.057 0.100 
11 -14.726 0.800 6 1.88300 
40.80 
12 108.732 11.787 
13 88.523 2.853 7 1.80518 
25.46 
14 -82.355 9.407 
15 -12.998 0.800 8 1.49700 
81.61 
16 -66.676 
Aspherical surfaces 
Ninth face 
K = -1.911422, A = -1.145100E-5, 
B = -1.243300E-7, C = 3.365760E-10, 
D = -8.579860E-12 
Fifteenth face 
K = -0.667695, A = -1.408860E-5, 
B = -1.982460E-8, C = -1.122060E-10, 
D = 3.423050E-13 
Variable amounts 
f 36.502 61.005 102.011 
D.sub.4 28.790 11.283 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.476 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.469 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 4.849, f.sub.2 (F)/f.sub.2 
= 1.305, .vertline.f.sub.1 .vertline./ 
.sqroot.[f(W) .multidot. f(T)] = 1.012 
______________________________________ 
Embodiment 14 
f = 36.5.about.102, FNO. = 2.86.about.5.89, .omega. = 63.6.about.23.8 
i R i D i j N j .nu. j 
______________________________________ 
1 -94.788 0.800 1 1.88300 
40.80 
2 32.720 1.478 
3 35.423 3.526 2 1.84666 
23.83 
4 161.893 variable 
5 17.416 6.092 3 1.51728 
69.68 
6 -43.366 0.800 4 1.75520 
27.53 
7 -103.785 3.408 
8 .infin. (diaphragm) 
1.616 
9 29.419 4.939 5 1.48749 
70.44 
10 - 22.746 0.100 
11 -23.002 0.800 6 1.88300 
40.80 
12 138.588 5.545 
13 .infin. (diaphragm) 
14.545 
14 54.944 2.549 7 1.80518 
25.46 
15 530.380 7.382 
16 -12.995 0.800 8 1.49700 
81.61 
17 -82.993 
Aspherical surfaces 
Ninth face 
K = -2.826032, A = -1.592680E-5, 
B = -2.022210E-7, C = 1.715790E-10, 
D = -8.917560E-12 
Sixteenth face 
K = -0.682310, A = -1.026700E-5, 
B = 3.801390E-8, C = -3.142820E-10, 
D = 9.291290E-13 
Variable amounts 
f 36.502 61.005 102.011 
D.sub.4 27.494 10.798 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.475 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.487 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.974, f.sub.2 (F)/f.sub.2 
= 1.308, .vertline.f.sub. 1 .vertline./ 
.sqroot.[f(W) .multidot. f(T)] = 1.977 
______________________________________ 
Embodiment 15 
f = 36.5.about.102, FNO. = 2.86.about.5.9, .omega. = 63.6.about.23.7 
i R i D i j N j .nu. j 
______________________________________ 
1 -93.737 0.800 1 1.91044 
40.80 
2 29.485 1.143 
3 31.487 4.299 2 1.84701 
25.46 
4 232.191 variable 
5 17.500 6.452 3 1.50451 
81.61 
6 -40.845 0.800 4 1.88470 
32.18 
7 -83.846 3.962 
8 .infin. (diaphragm) 
0.889 
9 33.759 4.794 5 1.50764 
65.13 
10 -23.442 0.100 
11 -25.203 0.800 6 1.91044 
40.80 
12 267.878 6.040 
13 .infin. (diaphragm) 
15.358 
14 170.032 2.257 7 1.89390 
23.83 
15 -128.398 6.334 
16 -12.593 0.800 8 1.50451 
81.61 
17 -88.621 
Aspherical surfaces 
Ninth face 
K = -4.002919, A = -1.860060E-5, 
B = -2.027060E-7, C = 1.822600E-10, 
D = -7.148930E-12 
Sixteenth face 
K = -0.705350, A = -7.596980E-6, 
B = 3.040990E-8, C = -3.140890E-10, 
D = 3.980540E-13 
Variable amounts 
f 36.499 60.998 101.997 
D.sub.4 28.172 11.052 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.470 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.471 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.553, f.sub.2 (F)/f.sub.2 
= 1.289, .vertline.f.sub.1 .vertline./ 
.sqroot.[f(W) .multidot. f(T)] = 1.999 
______________________________________ 
The above Embodiments 13 to 15 relate to the sixth lens structure of the 
present invention. 
FIG. 51 shows a lens arrangement in the Embodiment 13 at the wide angle end 
of the zoom lens. FIGS. 54, 55 and 56 respectively show aberration 
diagrams with respect to the Embodiment 13 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 52 shows a lens arrangement in the Embodiment 14 at the wide angle end 
of the zoom lens. FIGS. 57, 58 and 59 respectively show aberration 
diagrams with respect to the Embodiment 14 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 53 shows a lens arrangement in the Embodiment 15 at the wide angle end 
of the zoom lens. FIGS. 60, 61 and 62 respectively show aberration 
diagrams with respect to the Embodiment 15 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
______________________________________ 
Embodiment 16 
f = 36.5.about.102, FNO. = 2.88.about.5.89, .omega. = 63.7.about.23.5 
i R i D i j N j .nu. j 
______________________________________ 
1 -83.405 0.800 1 1.88300 
40.80 
2 32.250 1.214 
3 34.368 3.894 2 1.80518 
25.46 
4 364.341 variable 
5 15.709 6.746 3 1.48749 
70.44 
6 -87.196 0.800 4 1.84666 
23.83 
7 -567.432 0.800 
8 .infin. (diaphragm) 
0.800 
9 25.807 13.495 5 1.48749 
70.44 
10 -11.141 0.800 6 1.88300 
40.80 
11 1005.622 11.431 
12 96.113 3.513 7 1.74077 
27.76 
13 -47.797 9.183 
14 -12.686 0.800 8 1.49700 
27.76 
15 -124.117 
Aspherical surfaces 
Ninth face 
K = -1.126719, A = -5.804560E-6, 
B = -6.279070E-8, C = 4.121960E-10, 
D = -2.314510E-12 
Fourteenth face 
K = -0.751233, A = -1.433140E-5, 
B = -3.240980E-8, C = 5.046530E-11, 
D = -7.384360E-14 
Variable amounts 
f 36.500 61.000 102.002 
D.sub. 4 
28.725 11.259 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.445 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.427 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 5.280, f.sub.2 (F)/f.sub.2 
= 1.359, .vertline.f.sub.1 .vertline./ 
.sqroot.[f(W) .multidot. f(T)] = 1.033 
______________________________________ 
Embodiment 17 
f = 36.5.about.102, FNO. = 2.86.about.5.9, .omega. = 63.6.about.23.7 
i R i D i j N j .nu. j 
______________________________________ 
1 -96.368 0.800 1 1.88300 
40.80 
2 29.333 1.143 
3 31.271 4.290 2 1.80518 
25.46 
4 215.479 variable 
5 17.287 7.163 3 1.49700 
81.61 
6 -49.128 0.800 4 1.75520 
27.53 
7 -89.972 3.383 
8 .infin. (diaphragm) 
0.800 
9 26.130 5.426 5 1.49831 
65.13 
10 -22.379 0.800 6 1.88300 
40.80 
11 85.054 5.583 
12 .infin. (diaphragm) 
14.000 
13 55.578 2.742 7 1.76182 
26.55 
14 -1035.661 7.107 
15 -12.689 0.800 8 1.49700 
81.61 
16 -94.418 
Aspherical surfaces 
Ninth face 
K = -1.848904, A = -1.183250E-5, 
B = -2.243620E-7, C = 1.018300E-9, 
D = -1.612580E-11 
Fifteenth face 
K = -0.740928, A = -1.155710E-5, 
B = 1.328490E-8, C = -1.084310E-10, 
D = 3.918050E-13 
Variable amounts 
f 36.499 60.998 101.998 
D.sub.4 28.163 11.049 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.470 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.471 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.964, f.sub.2 (F)/f.sub.2 
= 1.311, .vertline.f.sub.1 .vertline./ 
.sqroot.[f(W) .multidot. f(T)] = 1.999 
______________________________________ 
Embodiment 18 
f = 36.5.about.102, FNO. = 2.87.about.5.9, .omega. = 63.5.about.23.8 
i R i D i j N j .nu. j 
______________________________________ 
1 -89.691 0.800 1 1.88300 
40.80 
2 30.634 1.138 
3 32.793 4.196 2 1.80518 
25.46 
4 274.523 variable 
5 16.964 10.565 3 1.49700 
81.61 
6 -26.742 0.800 4 1.88300 
40.80 
7 -42.109 0.800 
8 .infin. (diaphragm) 
0.800 
9 25.025 3.458 5 1.50378 
66.89 
10 -28.988 0.800 6 1.88300 
40.80 
11 51.825 7.049 
12 .infin. (diaphragm) 
14.911 
13 -289.068 2.440 7 1.84666 
23.83 
14 -51.411 5.860 
15 -11.477 0.800 8 1.49700 
81.61 
16 -68.109 
Aspherical surfaces 
Ninth face 
K = -1.876639, A = -1.354990E-5, 
B = 2.795920E-7, C = 9.625400E-10, 
D = 1.736270E-11 
Fifteenth face 
K = -0.831810, A = -1.301140E-5, 
B = -1.115230E-8, C = -2.800040E-10, 
D = -7.018640E-14 
Variable amounts 
f 36.499 60.997 101.996 
D.sub.4 28.523 11.184 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.468 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.462 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.570, f.sub.2 (F)/f.sub.2 
= 1.274, .vertline.f.sub.1 .vertline./ 
.sqroot.[f(W) .multidot. f(T)] = 1.011 
______________________________________ 
The above Embodiments 16 to 18 relate to the seventh lens structure of the 
present invention. 
FIG. 63 shows a lens arrangement in the Embodiment 16 at the wide angle end 
of the zoom lens. FIGS. 66, 67 and 68 respectively show aberration 
diagrams with respect to the Embodiment 16 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 64 shows a lens arrangement in the Embodiment 17 at the wide angle end 
of the zoom lens. FIGS. 69, 70 and 71 respectively show aberration 
diagrams with respect to the Embodiment 17 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 65 shows a lens arrangement in the Embodiment 18 at the wide angle end 
of the zoom lens. FIGS. 72, 73 and 74 respectively show aberration 
diagrams with respect to the Embodiment 18 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
______________________________________ 
Embodiment 19 
f=36.5.about.102,FNO.=2.91.about.5.9 , .omega.=63.4.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -91.278 0.800 1 1.88300 
40.80 
2 37.452 2.245 
3 42.209 3.274 2 1.84666 
23.83 
4 244.847 variable 
5 18.173 5.024 3 1.48749 
70.44 
6 -128.963 1.079 
7 .infin. (diaphragm) 
0.800 
8 20.967 3.407 4 1.53113 
62.07 
9 -159.080 0.263 
10 -78.430 3.364 5 1.88300 
40.80 
11 14.656 3.660 6 1.49700 
81.61 
12 -93.568 16.343 
13 91.451 2.314 7 1.62536 
35.58 
14 -144.274 5.281 
15 -13.015 0.800 8 1.75500 
52.32 
16 146.204 4.091 9 1.84666 
23.83 
17 -57.719 
Aspherical surfaces 
Eighth face 
K=-0.645038, A=-8.079200E-6, 
B=-7.314510E-8, C=9.162360E-11, 
D=-3.055630E-12 
Fifteenth face 
K=-0.578376, A=-1.276679E-5, 
B=-4.989200E-8, C= 1.349340E-10, 
D=-8.578690E-13 
Variable amounts 
f 36.505 61.000 102.021 
D.sub.4 
30.256 11.837 0.800 
Values of conditional formulas 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(W))-(f(W)/f.sub.1)}]/f(T)=0.471 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(T))-(f(T)/f.sub.1)}]/f(T)=0.441 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F)=1.198,f.sub.2 (F)/f.sub.2 
=1.191,.vertline.f.sub.1 .vertline./.sqroot.[f(W).multidot.f(T)]=1.057 
Embodiment 20 
f=36.5.about.102,FNO.=2.89.about.5.9 , .omega.=63.4.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 93.133 0.800 1 1.86300 
41.53 
2 34.789 2.409 
3 39.783 3.158 2 1.84666 
23.83 
4 180.181 variable 
5 19.481 4.699 3 1.50378 
66.89 
6 -141.457 1.778 
7 .infin. (diaphragm) 
0.800 
8 21.745 3.282 4 1.51728 
69.68 
9 -254.982 0.475 
10 -64.863 1.947 5 1.88300 
40.80 
11 17.437 5.949 6 1.49700 
81.61 
12 -42.406 16.689 
13 130.274 2.069 7 1.68893 
31.16 
14 -264.196 5.273 
15 -13.402 0.800 8 1.77250 
49.62 
16 121.430 4.311 9 1.84666 
23.83 
17 -55.099 
Aspherical surfaces 
Eighth face 
K=-0.613073, A=-8.173230E-6, 
B=-4.294320E-8, C=-5.828660E-11, 
D=-1.386860E-12 
Fifteenth face 
K=-0.458536, A=-8.571300E-6, 
B=-3.912120E-8, C= 4.287360E-11, 
D=-6.478640E-13 
Variable amounts 
f 36.500 61.000 102.001 
D.sub.4 
28.561 11.198 0.800 
Values of conditional formulas 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(W))-(f(W)/f.sub.1)}]/f(T)=0.472 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(T))-(f(T)/f.sub.1 (}]/f(T)=0.46 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F)=1.101,f.sub.2 (F)/f.sub.2 
=1.190,.vertline.f.sub.1 .vertline./.sqroot.[f(W).multidot.f(T)]=1.009 
Embodiment 21 
f=36.5.about.102,FNO.=2.85.about.5.8 , .omega.=63.3.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -103.619 0.800 1 1.88300 
40.80 
2 33.579 2.357 
3 38.362 3.228 2 1.84666 
23.83 
4 174.058 variable 
5 19.672 4.696 3 1.51728 
69.68 
6 -125.873 1.601 
7 .infin. (diaphragm) 
0.800 
8 21.454 3.536 4 1.52642 
60.11 
9 -575.287 0.628 
10 -70.835 1.618 5 1.87800 
38.20 
11 15.667 3.686 6 1.48749 
70.44 
12 -77.586 13.073 
13 153.113 2.212 7 1.60342 
38.01 
14 -83.410 11.591 
15 -13.505 0.800 8 1.67790 
55.52 
16 208.947 3.663 9 1.84666 
23.83 
17 -66.420 
Asherical surfaces 
Eighth face 
K=-0.487009, A=-6.415980E-6, 
B=-3.717720E-8, C=-1.489470E-11, 
D=-1.773150E-12 
Fifteenth face 
K=-0.473297, A=-9.275250E-6, 
B=-2.924420E-8, C=-1.307130E-10, 
D= 8.893610E-14 
Variable amounts 
f 36.501 61.000 102.002 
D.sub.4 
28.710 11.254 0.800 
Values of conditional formulas 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(W))-(f(W)/f.sub.1)}]/f(T)=0.484 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(T))-(f(T)/f.sub.1)}]/f(T)=0.482 
O 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F)=1.542,f.sub.2 (F)/f.sub.2 
=1.280,.vertline.f.sub.1 .vertline./.sqroot.[f(W).multidot.f(T)]=1.004 
______________________________________ 
The above Embodiments 19 to 21 relate to the eighth lens structure of the 
present invention. 
FIG. 75 shows a lens arrangement in the Embodiment 19 at the wide angle end 
of the zoom lens. FIGS. 78, 79 and 80 respectively show aberration 
diagrams with respect to the Embodiment 19 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 76 shows a lens arrangement in the Embodiment 20 at the wide angle end 
of the zoom lens. FIGS. 81, 82 and 83 respectively show aberration 
diagrams with respect to the Embodiment 20 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 77 shows a lens arrangement in the Embodiment 21 at the wide angle end 
of the zoom lens. FIGS. 84, 85 and 86 respectively show aberration 
diagrams with respect to the Embodiment 21 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
______________________________________ 
Embodiment 22 
f=36.0.about.102,FNO.=2.63.about.5.82, .omega.=64.1.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -80.625 1.000 1 1.83500 
42.98 
2 36.529 2.131 
3 40.705 4.001 2 1.84666 
23.83 
4 167.080 variable 
5 19.892 7.009 3 1.56732 
42.84 
6 1438.270 0.800 
7 21.525 4.373 4 1.51680 
64.20 
8 -91.736 0.296 
9 -67.620 1.000 5 1.85030 
32.18 
10 14.686 4.968 6 1.48749 
70.44 
11 -51.789 3.128 
12 .infin.(diaphragm) 
13.525 
13 11325.127 5.607 7 1.76182 
26.55 
14 -15.908 1.000 8 1.88300 
40.80 
15 -89.201 5.803 
16 -12.652 1.000 9 1.4879 70.44 
17 -71.740 
Aspherical surfaces 
Seventh face 
K=-0.605240, A=-8.412010E-6, 
B=-4.542690E-8, C=-6.760200E-11, 
D=-4.710010E-14 
Sixteenth face 
K=-0.430238, A= 4.459480E-6, 
B= 4.992070E-8, C=-2.998690E-10, 
D= 6.455410E-13 
Variable amounts 
f 36.000 60.600 102.003 
D.sub.4 
27.358 10.697 0.800 
Values of conditional formulas 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(W))-(f(W)/f.sub.1)}]/f(T)=0.430 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(T))-(f(T)/f.sub.1)}]/f(T)=0.431 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F)=1.134,f.sub.2 (F)/f.sub.2 
=1.251,.vertline.f.sub.1 .vertline./.sqroot.[f(W).multidot.f(T)]=0.999 
Embodiment 23 
f=36.0.about.102,FNO.=2.63.about.5.83, .omega.=64.1.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -75.610 1.000 1 1.83500 
42.98 
2 36.909 1.755 
3 40.442 4.041 2 1.84666 
23.83 
4 183.707 variable 
5 20.506 7.045 3 1.56138 
45.23 
6 -250.205 0.800 
7 24.543 3.773 4 1.51680 
64.20 
8 -116.994 0.551 
9 -58.118 1.000 5 1.85030 
32.18 
10 18.648 8.695 6 1.49700 
81.61 
11 -33.248 1.000 
12 .infin. (diaphragm) 
12.713 
13 -56.396 6.860 7 1.78470 
26.06 
14 -11.814 1.000 8 1.88300 
40.80 
15 -51.477 4.970 
16 -12.778 1.000 9 1.62041 
60.34 
17 -39.766 
Aspherical surfaces 
Seventh face 
K=-0.806579, A=-1.114560E- 5, 
B=-5.087680E-8, C=-1.061220E-10, 
D= 1.804690E-13 
Sixteenth face 
K=-0.551248, A=-7.168390E-6, 
B= 7.924650E-9, C=-3.134230E-10, 
D= 4.440330E-13 
Variable amounts 
f 35.998 60.600 101.987 
D.sub.4 
26.796 10.485 0.800 
Values of conditional formulas 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(W))-(f(W)/f.sub.1)}]/f(T)=0.409 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(T))-(f(T)/f.sub.1)}]/f(T)=0.409 
O 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F)=0.884,f.sub.2 (F)/f.sub.2 
=1.192,.vertline.f.sub.1 .vertline./.sqroot.[f(W).multidot.f(T)]=0.999 
Embodiment 24 
f=36.0.about.102,FNO.=2.63.about.5.72, .omega.=64.2.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -91.646 1.000 1 1.83500 
42.98 
2 34.451 1.962 
3 38.127 3.486 2 1.84666 
23.83 
4 135.124 variable 
5 19.380 6.651 3 1.56013 
47.09 
6 -527.865 0.800 
7 20.824 4.502 4 1.52310 
50.95 
8 -74.899 0.230 
9 -61.063 1.000 5 1.85030 
32.18 
10 13.238 4.433 6 1.48749 
70.44 
11 -102.437 1.646 
12 .infin. (diaphragm) 
15.742 
13 83.028 4.838 7 1.74000 
28.24 
14 -27.938 1.000 8 1.80420 
46.50 
15 -408.800 6.688 
16 -13.369 1.000 9 1.49700 
81.61 
17 -114.746 
Aspherical surfaces 
Seventh face 
K=-0.494716, A=-6.627180E-6, 
B=-3.724730E-8, C=-1.363710E-10, 
D=-2.083340E-13 
Sixteenth face 
K=-0.191188, A= 1.127990E-5, 
B= 2.229420E-7, C=-1.764820E-9 
D= 8.544660E-12 
Variable amounts 
f 35.999 60.600 101.994 
D.sub.4 
27.671 10.812 0.800 
Values of conditional formulas 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(W))-(f(W)/f.sub.1)}]/f(T)=0.443 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(T))-(f(T)/f.sub.1)}]/f(T)=0.443 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F)=1.458,f.sub.2 (F)/f.sub.2 
=1.299,.vertline.f.sub.1 .vertline./.sqroot.[f(W).multidot.f(T)]=0.998 
______________________________________ 
The above Embodiments 22 to 24 relate to the ninth lens structure of the 
present invention. 
FIG. 87 shows a lens arrangement in the Embodiment 22 at the wide angle end 
of the zoom lens. FIGS. 90, 91 and 92 respectively show aberration 
diagrams with respect to the Embodiment 22 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 88 shows a lens arrangement in the Embodiment 23 at the wide angle end 
of the zoom lens. FIGS. 93, 94 and 95 respectively show aberration 
diagrams with respect to the Embodiment 23 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 89 shows a lens arrangement in the Embodiment 24 at the wide angle end 
of the zoom lens. FIGS. 96, 97 and 98 respectively show aberration 
diagrams with respect to the Embodiment 24 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
______________________________________ 
Embodiment 25 
f=36.0.about.102,FNO.=2.57.about.5.83, .omega.=64.1.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -61.418 1.000 1 1.83500 
42.98 
2 33.751 1.016 
3 35.790 3.918 2 1.84666 
23.83 
4 183.457 variable 
5 22.336 7.558 3 1.58144 
40.89 
6 -46.965 0.800 4 1.81600 
46.57 
7 -103.565 0.100 
8 25.009 6.610 5 1.58215 
42.03 
9 -573.108 0.590 
10 -74.148 1.000 6 1.84666 
23.83 
11 17.355 3.984 7 1.49700 
81.61 
12 -50.013 1.083 
13 .infin. (diaphragm) 
12.848 
14 150.426 7.784 8 1.80518 
25.46 
15 -12.741 1.000 9 1.88300 
40.80 
16 -120.777 5.285 
17 -14.088 1.000 10 1.74100 
52.60 
18 -49.932 
Aspherical surfaces 
Eighth face 
K=-0.522658, A=-7.735500E-6, 
B=-2.706230E-8, C=-5.887230E-11, 
D= 2.172690E-14 
Seventeenth face 
K=-0.285776, A= 7.434240E-6, 
B= 9.051810E-8, C=-5.574160E-10, 
D= 3.129480E-12 
Variable amounts 
f 36.000 60.600 101.999 
D.sub.4 
21.469 8.502 0.800 
Values of conditional formulas 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(W))-(f(W)/f.sub.1)}]/f(T)=0.354 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(T))-(f(T)/f.sub.1)}]/f(T)=0.412 
O 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F)=1.221,f.sub.2 (F)/f.sub.2 
=1.325,.vertline.f.sub.1 .vertline./.sqroot.[f(W).multidot.f(T)]=0.881 
Embodiment 26 
f=36.0.about.102,FNO.=2.55.about.5.83, .omega.=64.1.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -60.769 1.000 1 1.83500 
42.98 
2 34.347 0.903 
3 36.154 4.212 2 1.84666 
23.83 
4 196.627 variable 
5 21.286 8.775 3 1.59551 
39.22 
6 -43.099 0.800 4 1.78800 
47.49 
7 -121.542 0.100 
8 24.645 3.429 5 1.56732 
42.84 
9 -457.413 0.680 
10 -84.079 1.000 6 1.84666 
23.83 
11 18.556 8.919 7 1.49700 
81.61 
12 -36.681 1.000 
13 .infin. (diaphragm) 
11.791 
14 -90.418 5.902 8 1.84666 
23.83 
15 -12.365 1.000 9 1.88300 
40.80 
16 -94.100 5.297 
17 -12.796 1.000 10 1.75500 
52.32 
18 -32.878 
Aspherical surfaces 
Eighth face 
K=-0.852202, A=-1.070340E-5, 
B=-5.050010E-8, C=-9.703920E-11, 
D= 6.861860E-14 
Seventeenth face 
K=-0.312935, A= 6.673730E-7, 
B= 6.567600E-8, C=-6.453610E-10, 
D= 1.99940E-12 
Variable amounts 
f 36.000 60.600 102.000 
D.sub.4 
21.94 8.677 0.800 
Values of conditional formulas 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(W))-(f(W)/f.sub.1)}]/f(T)=0.356 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(T))-(f(T)/f.sub.1)}]/f(T)=0.408 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F)=0.926,f.sub.2 (F)/f.sub.2 
=1.254,.vertline.f.sub.1 .vertline./.sqroot.[f(W).multidot.f(T)]=0.894 
Embodiment 27 
f=36.0.about.102,FNO.=2.58.about.5.83, .omega.=64.1.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -66.190 1.000 1 1.83500 
42.98 
2 36.171 1.068 
3 38.387 4.308 2 1.84666 
23.83 
4 200.503 variable 
5 23.013 8.716 3 1.60000 
42.46 
6 -41.373 0.800 4 1.85030 
32.18 
7 -92.635 0.100 
8 22.418 8.246 5 1.57309 
42.59 
9 -757.015 0.614 
11 -67.261 1.000 6 1.84666 
23.83 
11 15.437 3.273 7 1.49700 
81.61 
12 -161.713 1.000 
13 .infin. (diaphragm) 
9.884 
14 70.147 7.673 8 1.80518 
25.46 
15 -12.469 1.000 9 1.88300 
40.80 
16 -260.008 6.300 
17 -13.884 1.000 10 1.75500 
52.32 
18 -37.510 
Aspherical surfaces 
Eighth face 
K=-0.304235, A=-4.712040E-6, 
B=-1.801520E-8, C=-5.923790E-11, 
D= 4.836310E-14 
Seventeenth face 
K=-0.154324, A= 8.720100E-6, 
B 1.506690E-7, C=-1.206140E-9 , 
D= 7.416100E-12 
Variable amounts 
f 36.000 60.600 102.003 
D.sub.4 
24.537 9.646 0.800 
Values of conditional formulas 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(W))-(f(W)/f.sub.1)}]/f(T)=0.384 
[f.sub.1 +f.sub.2 .multidot.{2-(f.sub.1 /f(T))-(f(T)/f.sub.1)}]/f(T)=0.408 
O 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F)=1.557,f.sub.2 (F)/f.sub.2 
=1.312,.vertline.f.sub.1 .vertline./.sqroot. [f(W).multidot.f(T)]=0.951 
______________________________________ 
The above Embodiments 25 to 27 relate to the tenth lens structure of the 
present invention. 
FIG. 99 shows a lens arrangement in the Embodiment 25 at the wide angle end 
of the zoom lens. FIGS. 102, 103 and 104 respectively show aberration 
diagrams with respect to the Embodiment 25 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 100 shows a lens arrangement in the Embodiment 26 at the wide angle 
end of the zoom lens. FIGS. 105, 106 and 107 respectively show aberration 
diagrams with respect to the Embodiment 26 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 101 shows a lens arrangement in the Embodiment 27 at the wide angle 
end of the zoom lens. FIGS. 108, 109 and 110 respectively show aberration 
diagrams with respect to the Embodiment 27 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
______________________________________ 
Embodiment 28 
f = 36.0.about.102, FNO. = 2.56.about.5.83, .omega. = 64.1.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -60.334 1.000 1 1.83500 
42.98 
2 33.780 0.925 
3 35.581 3.947 2 1.84666 
23.83 
4 185.325 variable 
5 23.093 8.677 3 1.60342 
38.01 
6 -174.678 0.100 
7 24.442 6.488 4 1.60562 
43.88 
8 -32.306 0.800 5 1.80740 
35.54 
9 -235.039 0.321 
10 -101.312 1.000 6 1.84666 
23.83 
11 16.974 3.759 7 1.49700 
81.61 
12 -63.284 1.000 
13 .infin.(diaphragm) 
12.520 
14 124.161 7.988 8 1.80518 
25.46 
15 -12.663 1.000 9 1.88300 
40.80 
16 -105.217 5.187 
17 -14.086 1.000 10 1.75500 
52.32 
18 -52.578 
Aspherical surfaces 
Seventh face 
K = -0.352659, A = -5.953150E-6, 
B = -2.050360E-8, C = -2.901880E-11, 
D = -2.548950E-14 
Seventeenth face 
K = -0.288490, A = 8.654120E-6, 
B = 8.796030E-8, C = -5.115910E-10, 
D = 3.171100E-12 
Variable amounts 
f 36.999 60.600 101.995 
D.sub.4 21.172 8.391 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.348 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.408 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.283, f.sub.2 (F)/f.sub.2 
= 1.337, 
.vertline.f.sub.1 .vertline./ .sqroot. [f(W) .multidot. f(T)] = 0.877 
Embodiment 29 
f = 36.0.about.102, FNO. = 2.57.about.5.83, .omega. = 64.1.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -64.938 1.000 1 1.83500 
42.98 
2 34.765 1.129 
3 37.002 4.157 2 1.84666 
23.83 
4 185.059 variable 
5 21.633 7.653 3 1.57845 
41.71 
6 -344.323 0.100 
7 26.543 5.563 4 1.60801 
46.21 
8 -26.746 0.800 5 1.77250 
49.62 
9 610.086 0.374 
10 -772.511 1.000 6 1.84666 
23.83 
11 16.700 7.858 7 1.51728 
69.68 
12 -34.806 1.000 
13 .infin.(diaphragm) 
11.826 
14 -56.799 6.510 8 1.84666 
23.83 
15 -12.097 1.000 9 1.88300 
40.80 
16 -58.249 4.840 
17 -13.117 1.000 10 1.75500 
52.32 
18 -34.901 
Aspherical surfaces 
Seventh face 
K = -0.675311, A = -8.876040E-6, 
B = -3.265620E-8, C = -3.699420E-12, 
D = 1.365260E-13 
Seventeenth face 
K = -0.354570, A = -6.799940E-7, 
B = 6.194770E-8, C = -6.534670E-10, 
D = 2.169570E-12 
Variable amounts 
f 36.001 60.600 102.007 
D.sub.4 23.036 9.087 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.369 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1 
)}]/f(T) = 0.410 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 0.927, 
f.sub.2 (F)/f.sub.2 = 1.223, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 0.918 
Embodiment 30 
f = 36.0.about.102, FNO. = 2.63.about.5.8, .omega. = 64.1.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -77.426 1.000 1 1.83500 
42.98 
2 37.063 1.958 
3 40.831 3.925 2 1.84666 
23.83 
4 174.899 variable 
5 21.716 6.452 3 1.62004 
36.30 
6 -328.224 0.270 
7 25.296 6.955 4 1.62000 
62.19 
8 -36.867 0.800 5 1.76180 
26.91 
9 150.371 0.512 
10 533.144 1.000 6 1.85030 
32.18 
11 12.879 3.818 7 1.49700 
81.61 
12 -212.922 1.127 
13 .infin.(diaphragm) 
13.649 
14 107.999 7.756 8 1.80518 
25.46 
15 -14.599 1.000 9 1.88300 
40.80 
16 -91.917 4.744 
17 -16.046 1.000 10 1.80420 
46.50 
18 -58.721 
Aspherical surfaces 
Seventh face 
K = -0.412064, A = -6.363340E-6, 
B = -3.188570E-8, C = 3.932880E-11, 
D = -4.376580E-13 
Seventeenth face 
K = -0.006337, A = 1.444680E-5, 
B = 1.090300E-7, C = -4.686770E-10, 
D = 2.955380E-12 
Variable amounts 
f 36.000 60.600 102.001 
D.sub.4 27.034 10.575 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.418 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f( 
T) = 0.419 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.504, 
f.sub.2 (F)/f.sub.2 = 1.290, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 0.998 
______________________________________ 
The above Embodiments 28 to 30 relate to the eleventh lens structure of the 
present invention. 
FIG. 111 shows a lens arrangement in the Embodiment 28 at the wide angle 
end of the zoom lens. FIGS. 114, 115 and 116 respectively show aberration 
diagrams with respect to the Embodiment 28 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 112 shows a lens arrangement in the Embodiment 29 at the wide angle 
end of the zoom lens. FIGS. 117, 118 and 119 respectively show aberration 
diagrams with respect to the Embodiment 29 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 113 shows a lens arrangement in the Embodiment 30 at the wide angle 
end of the zoom lens. FIGS. 120, 121 and 122 respectively show aberration 
diagrams with respect to the Embodiment 30 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
______________________________________ 
Embodiment 31 
f = 36.0.about.102, FNO. = 2.76.about.5.83, .omega. = 64.1.about.23.6 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -78.592 0.800 1 1.88300 
40.80 
2 34.145 1.303 
3 36.812 3.613 2 1.84666 
23.83 
4 266.720 variable 
5 20.099 7.890 3 1.56138 
45.23 
6 -37.519 0.800 4 1.72342 
37.99 
7 -86.115 2.210 
8 .infin.(diaphragm) 
1.000 
9 23.986 5.751 5 1.58904 
52.93 
10 -22.289 1.000 6 1.84666 
23.83 
11 40.092 14.407 
12 58.823 8.368 7 1.75520 
27.53 
13 -13.233 1.000 8 1.84750 
43.03 
14 -175.759 5.956 
15 -13.661 1.200 9 1.75500 
52.32 
16 -36.621 
Aspherical surfaces 
Ninth face 
K = -0.846599, A = -5.758720E-6, 
B = -2.974170E-8, C = -2.931230E-10, 
D = -6.230980E-13 
Fifteenth face 
K = -0.709678, A = -1.724500E-5, 
B = 2.211860E-8, C = -5.202740E-10, 
D = 2.248820E-12 
Variable amounts 
f 36.000 60.600 102.000 
D.sub.4 25.9817 10.186 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.417 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.433 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.679, 
f.sub.2 (F)/f.sub.2 = 1.325, .vertline.f.sub.1 .vertline./ .sqroot. [f(W) 
.multidot. f(T)] = 0.969 
Embodiment 32 
f = 36.0.about.102, FNO. = 2.79.about.5.83, .omega. = 64.1.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -75.718 0.800 1 1.88300 
40.80 
2 31.613 0.854 
3 33.068 4.443 2 1.78472 
25.70 
4 814.262 variable 
5 20.278 6.324 3 1.53256 
45.94 
6 -39.688 3.415 4 1.78800 
47.49 
7 -61.881 1.000 
8 .infin.(diaphragm) 
1.000 
9 24.360 4.096 5 1.55671 
58.56 
10 -27.498 1.000 6 1.84666 
23.83 
11 53.547 16.539 
12 124.097 7.596 7 1.75520 
27.53 
13 -12.399 1.000 8 1.88300 
40.80 
14 -96.981 5.853 
15 -12.455 1.200 9 1.65160 
58.40 
16 -37.922 
Aspherical surfaces 
Ninth face 
K = -0.726870, A = -4.710440E-6, 
B = -1.879390E-8, C = -3.439890E-10, 
D = -3.300030E-13 
Fifteenth face 
K = -0.735749, A = -1.899560E-5, 
B = 1.999390E-8, C = -7.556820E-10, 
D = 3.136680E-12 
Variable amounts 
f 36.000 60.600 101.998 
D.sub.4 27.867 10.886 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.416 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f( 
T) = 0.403 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.167, 
f.sub.2 (F)/f.sub.2 = 1.272, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 1.024 
Embodiment 33 
f = 36.0.about.102, FNO. = 2.76.about.5.83, .omega. = 64.1.about.23.6 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -78.808 0.800 1 1.88300 
40.80 
2 35.376 1.250 
3 37.789 3.752 2 1.84666 
23.83 
4 242.292 variable 
5 19.171 9.588 3 1.56138 
45.23 
6 -29.928 0.800 4 1.76200 
40.26 
7 -67.594 1.769 
8 .infin.(diaphragm) 
1.000 
9 20.660 5.356 5 1.56965 
49.39 
10 -20.354 2.142 6 1.84666 
23.83 
11 28.493 12.776 
12 55.303 9.134 7 1.75520 
27.53 
13 -12.964 1.000 8 1.80420 
46.50 
14 -106.695 5.462 
15 -14.359 1.200 9 1.81550 
44.54 
16 -44.968 
Aspherical surfaces 
Ninth face 
K = -0.678334, A = -3.650590E-6, 
B = -9.237590E-8, C = 6.933350E-10, 
D = -7.909810E-12 
Fifteenth face 
K = -0.722949, A = -1.311790E-5, 
B = 9.793000E-9, C = -2.770860E-10, 
D = 1.465170E-12 
Variable amounts 
f 36.000 60.600 101.997 
D.sub.4 26.971 10.552 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.415 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f( 
T) = 0.415 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 2.117, 
f.sub.2 (F)/f.sub.2 = 1.343, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 0.999 
______________________________________ 
The above Embodiments 31 to 33 relate to the twelfth lens structure of the 
present invention. 
FIG. 123 shows a lens arrangement in the Embodiment 31 at the wide angle 
end of the zoom lens. FIGS. 126, 127 and 128 respectively show aberration 
diagrams with respect to the Embodiment 31 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 124 shows a lens arrangement in the Embodiment 32 at the wide angle 
end of the zoom lens. FIGS. 129, 130 and 131 respectively show aberration 
diagrams with respect to the Embodiment 32 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 125 shows a lens arrangement in the Embodiment 33 at the wide angle 
end of the zoom lens. FIGS. 132, 133 and 134 respectively show aberration 
diagrams with respect to the Embodiment 33 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
______________________________________ 
Embodiment 34 
f = 36.0.about.102, FNO. = 2.60.about.5.83, .omega. = 64.1.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -61.621 1.200 1 1.83500 
42.98 
2 31.535 0.917 
3 33.436 3.678 2 1.84666 
23.83 
4 157.237 variable 
5 20.207 6.041 3 1.60342 
38.01 
6 -237.200 0.100 
7 23.182 5.082 4 1.56732 
42.84 
8 -264.322 0.502 
9 -77.694 0.800 5 1.84666 
23.83 
10 16.218 4.193 6 1.48749 
70.44 
11 -56.061 1.000 
12 .infin.(diaphragm) 
11.415 
13 145.779 7.047 7 1.69895 
30.05 
14 -11.730 1.000 8 1.83500 
42.98 
15 -58.891 4.191 
16 -13.297 1.200 9 1.75500 
52.32 
17 -10497.704 3.051 10 1.84666 
23.83 
18 -61.397 
Aspherical surfaces 
Seventh face 
K = -0.674250, A = -9.292730E-6, 
B = -3.797490E-8, C = -1.787200E-10, 
D = 2.988110E-13 
Sixteenth face 
K = -0.157338, A = -1.466430E-5, 
B = 1.849020E-7, C = -1.543130E-9, 
D = 1.043310E-11 
Variable amounts 
f 36.000 50.811 102.003 
D.sub.4 26.328 11.531 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.358 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.436 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.189, 
f.sub.2 (F)/f.sub.2 = 1.234, .vertline.f.sub.1 .vertline./ .sqroot. [f(W) 
.multidot. f(T)] = 0.844 
Embodiment 35 
f = 36.0.about.102, FNO. = 2.61.about.5.88, .omega. = 64.1.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -77.523 1.200 1 1.88300 
40.80 
2 31.489 1.047 
3 33.625 4.798 2 1.84666 
23.83 
4 190.541 variable 
5 19.146 7.762 3 1.61700 
62.83 
6 -68285.929 0.100 
7 24.454 3.766 4 1.59181 
58.31 
8 -185.395 1.029 
9 -57.432 1.018 5 1.85030 
32.18 
10 23.155 8.052 6 1.51728 
69.68 
11 -27.941 1.021 
12 .infin.(diaphragm) 
1.218 
13 -51.024 9.554 7 1.63636 
35.34 
14 -10.613 1.000 8 1.88300 
40.80 
15 -47.608 7.405 
16 -13.103 1.200 9 1.75500 
52.32 
17 248.312 4.152 10 1.84666 
23.83 
18 -39.790 
Aspherical surfaces 
Seventh face 
K = -0.846484, A = -1.123220E-5, 
B = -4.844920E-8, C = -2.694080E-10, 
D = 2.512570E-13 
Sixteenth face 
K = 0.265859, A = 1.883870E-5, 
B = 5.649070E-7, C = -7.339580E-9, 
D = 5.526810E-11 
Variable amounts 
f 36.001 60.600 102.003 
D.sub.4 24.042 9.461 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.415 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}] 
/f(T) = 0.459 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.204, 
f.sub.2 (F)/f.sub.2 = 1.099, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 0.915 
Embodiment 36 
f = 36.0.about.102, FNO. = 2.63.about.5.76, .omega. = 64.1.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -92.491 1.200 1 1.83500 
42.98 
2 32.780 2.229 
3 36.945 3.873 2 1.84666 
23.83 
4 125.708 variable 
5 20.837 6.449 3 1.60342 
38.01 
6 -675.014 0.100 
7 20.323 5.929 4 1.56732 
42.84 
8 -316.249 0.614 
9 -77.437 0.800 5 1.84666 
23.83 
10 13.506 4.006 6 1.48749 
70.44 
11 -257.928 1.640 
12 .infin.(diaphragm) 
7.487 
13 66.743 5.615 7 1.69895 
30.05 
14 -12.854 1.000 8 1.83500 
42.98 
15 -96.787 8.929 
16 -14.214 1.200 9 1.75500 
52.32 
17 -232.465 3.172 10 1.84666 
23.83 
18 -47.177 
Aspherical surfaces 
Seventh face 
K = -0.275641, A = -4.139550E-6, 
B = -9.532950E-9, C = -1.518280E-10, 
D = 5.091090E-13 
Sixteenth face 
K = 0.099137, A = 1.172160E-5, 
B = 2.328820E-7, C = -2.178070E-9, 
D = 1.493420E-11 
Variable amounts 
f 36.003 60.600 101.943 
D.sub.4 26.289 10.295 0.800 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.448 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f( 
T) = 0.472 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.055, 
f.sub.2 (F)/f.sub.2 = 1.163, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 0.956 
______________________________________ 
The above Embodiments 34 to 36 relate to the thirteenth lens structure of 
the present invention. 
FIG. 135 shows a lens arrangement in the Embodiment 34 at the wide angle 
end of the zoom lens. FIGS. 138, 139 and 140 respectively show aberration 
diagrams with respect to the Embodiment 34 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 136 shows a lens arrangement in the Embodiment 35 at the wide angle 
end of the zoom lens. FIGS. 141, 142 and 143 respectively show aberration 
diagrams with respect to the Embodiment 35 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 137 shows a lens arrangement in the Embodiment 36 at the wide angle 
end of the zoom lens. FIGS. 144, 145 and 146 respectively show aberration 
diagrams with respect to the Embodiment 36 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
______________________________________ 
Embodiment 37 
f = 36.0.about.102, FNO. = 3.92.about.5.83, .omega. = 64.1.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -75.610 1.000 1 1.83500 
42.98 
2 36.909 1.755 
3 40.442 4.041 2 1.84666 
23.83 
4 183.707 variable 
5 20.506 7.045 3 1.56138 
45.23 
6 -250.205 0.800 
7 24.543 3.773 4 1.51680 
64.20 
8 -116.994 0.551 
9 -58.118 1.000 5 1.85030 
32.18 
10 18.648 8.695 6 1.49700 
81.61 
11 -33.248 variable 
12 .infin.(diaphragm) 
variable 
13 -56.396 6.860 7 1.78470 
26.06 
14 -11.814 1.000 8 1.88300 
40.80 
15 -51.477 4.970 
16 -12.778 1.000 9 1.62041 
60.34 
17 -39.766 
Aspherical surfaces 
Seventh face 
K = -0.806579, A = -1.114560E-5, 
B = -5.087680E-8, C = -1.061220E-10, 
D = 1.804690E-13 
Sixteenth face 
K = -0.551248, A = -7.168390E-6, 
B = 7.924650E-9, C = -3.134230E-10, 
D = 4.440330E-13 
Variable amounts 
f 35.998 60.600 101.988 
D.sub.4 26.796 10.485 0.800 
D.sub.11 
1.000 5.181 12.213 
D.sub.12 
12.713 8.533 1.500 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.409 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.409 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 0.884, 
f.sub.2 (F)/f.sub.2 = 1.192, .vertline.f.sub.1 .vertline./ .sqroot. [f(W) 
.multidot. f(T)] = 0.999 
Embodiment 38 
f = 36.0.about.102, FNO. = 3.16.about.5.83, .omega. = 64.1.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -66.190 1.000 1 1.83500 
42.98 
2 36.171 1.068 
3 38.387 4.308 2 1.84666 
23.83 
4 200.503 variable 
5 23.013 8.716 3 1.60000 
42.46 
6 -41.373 0.800 4 1.85030 
32.18 
7 -92.635 0.100 
8 22.418 8.246 5 1.57309 
42.59 
9 -757.015 0.614 
10 -67.261 1.000 6 1.84666 
23.83 
11 15.437 3.273 7 1.49700 
81.61 
12 -161.713 variable 
13 .infin.(diaphragm) 
variable 
14 70.147 7.673 8 1.80518 
25.46 
15 -12.469 1.000 9 1.88300 
40.80 
16 -260.008 6.300 
17 -13.884 1.000 10 1.75500 
52.32 
18 -37.510 
Aspherical surfaces 
Eighth face 
K = -0.304235, A = -4.712040E-6, 
B = -1.801520E-8, C = -5.923790E-11, 
D = 4.836310E-14 
Seventeenth face 
K = -0.154324, A = 8.720100E-6, 
B = 1.506690E-7, C = -1.206140E-9, 
D = 7.416100E-12 
Variable amounts 
f 36.000 60.600 102.003 
D.sub.4 24.537 9.646 0.800 
D.sub.12 
1.000 4.125 9.384 
D.sub.13 
9.884 6.759 1.500 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1 
)}]/f(T) = 0.384 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f( 
T) = 0.408 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.557, 
f.sub.2 (F)/f.sub.2 = 1.312, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 0.951 
Embodiment 39 
f = 36.0.about.102, FNO. = 3.32.about.5.65, .omega. = 64.1.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -60.334 1.000 1 1.83500 
42.98 
2 33.780 0.925 
3 35.581 3.947 2 1.84666 
23.83 
4 185.325 variable 
5 23.093 8.677 3 1.60342 
38.01 
6 -174.678 0.100 
7 24.442 6.488 4 1.60562 
43.88 
8 -32.306 0.800 5 1.80740 
35.54 
9 -235.039 0.321 
10 -101.312 1.000 6 1.84666 
23.83 
11 16.974 3.759 7 1.49700 
81.61 
12 -63.284 variable 
13 .infin.(diaphragm) 
variable 
14 124.161 7.988 8 1.80518 
25.46 
15 -12.663 1.000 9 1.88300 
40.80 
16 -105.217 5.187 
17 -14.086 1.000 10 1.75500 
52.32 
18 -52.578 
Aspherical surfaces 
Seventh face 
K = -0.352659, A = -5.953150E-6, 
B = -2.050360E-8, C = -2.901880E-11, 
D = -2.548950E-14 
Seventeenth face 
K = -0.288490, A = 8.654120E-6, 
B = 8.796030E-8, C = -5.115910E-10, 
D = 3.171100E-12 
Variable amounts 
f 35.999 60.600 101.995 
D.sub.4 21.172 8.391 0.800 
D.sub.12 
1.000 4.108 12.020 
D.sub.13 
12.520 9.412 1.500 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.348 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f( 
T) = 0.408 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.283, 
f.sub.2 (F)/f.sub.2 = 1.337, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 0.877 
Embodiment 40 
f = 36.0.about.102, FNO. = 3.50.about.5.82, .omega. = 64.1.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -61.621 1.200 1 1.83500 
42.98 
2 31.535 0.917 
3 33.436 3.678 2 1.84666 
23.83 
4 157.237 variable 
5 20.207 6.041 3 1.60342 
38.01 
6 -237.200 0.100 
7 23.182 5.082 4 1.56732 
42.84 
8 -264.322 0.502 
9 -77.694 0.800 5 1.84666 
23.83 
10 16.218 4.193 6 1.48749 
70.44 
11 -56.061 variable 
12 .infin.(diaphragm) 
variable 
13 145.779 7.047 7 1.69895 
30.05 
14 -11.730 1.000 8 1.83500 
42.98 
15 -58.891 4.191 
16 -13.297 1.200 9 1.75500 
52.32 
17 -10497.704 3.051 10 1.84666 
23.83 
18 -61.397 
Aspherical surfaces 
Seventh face 
K = -0.674250, A = -9.292730E-6, 
B = -3.797490E-8, C = -1.787200E-10, 
D = 2.988110E-13 
Sixteenth face 
K = -0.157338, A = 1.466430E-5, 
B = 1.849020E-7, C = -1.543130E-9, 
D = 1.043310E-11 
Variable amounts 
f 36.000 50.811 102.003 
D.sub.4 20.328 11.531 0.800 
D.sub.11 
1.000 2.225 10.915 
D.sub.12 
11.415 10.190 1.500 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.358 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f( 
T) = 0.436 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.189, 
f.sub.2 (F)/f.sub.2 = 1.234, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 0.844 
______________________________________ 
The above Embodiments 37 to 40 relate to the fourteenth lens structure of 
the present invention. 
FIG. 147 shows a lens arrangement in the Embodiment 37 at the wide angle 
end of the zoom lens. FIGS. 151, 152 and 153 respectively show aberration 
diagrams with respect to the Embodiment 37 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. The above Embodiment 37 also relates to 
the fifteenth lens structure of the present invention. 
FIG. 148 shows a lens arrangement in the Embodiment 38 at the wide angle 
end of the zoom lens. FIGS. 154, 155 and 156 respectively show aberration 
diagrams with respect to the Embodiment 38 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. The above Embodiment 38 also relates to 
the sixteenth lens structure of the present invention. 
FIG. 149 shows a lens arrangement in the Embodiment 39 at the wide angle 
end of the zoom lens. FIGS. 157, 158 and 159 respectively show aberration 
diagrams with respect to the Embodiment 39 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. The above Embodiment 39 also relates to 
the seventeenth lens structure of the present invention. 
FIG. 150 shows a lens arrangement in the Embodiment 40 at the wide angle 
end of the zoom lens. FIGS. 160, 161 and 162 respectively show aberration 
diagrams with respect to the Embodiment 40 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. The above Embodiment 40 also relates to 
the eighteenth lens structure of the present invention. 
______________________________________ 
Embodiment 41 
f = 36.5.about.102, FNO. = 2.89.about.5.9, .omega. = 63.3.about.23.6 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -82.478 1.221 1 1.83400 
37.34 
2 28.647 0.871 
3 30.543 4.510 2 1.84666 
23.83 
4 181.540 variable 
5 19.466 7.648 3 1.51823 
58.96 
6 -93.610 1.537 
7 .infin.(diaphragm) 
0.800 
8 26.409 4.253 4 1.54814 
45.82 
9 -29.127 0.990 5 1.84666 
23.83 
10 56.893 3.949 
11 .infin.(diaphragm) 
variable 
12 75.006 7.593 6 1.69895 
30.05 
13 -13.437 1.326 7 1.83300 
40.80 
14 -163.240 6.368 
15 -11.992 0.944 9 1.49700 
81.61 
16 -35.711 
Aspherical surfaces 
Eighth face 
K = -1.068895, A = -7.529721E-6, 
B = -7.581887E-8, C = 1.848291E-10, 
D = -4.184132E-12 
Fifteenth face 
K = -0.720314, A = -2.032129E-5, 
B = 3.981674E-8, C = -1.029337E-9, 
D = 3.613058E-12 
Variable amounts 
f 36.502 61.005 102.010 
D.sub.4 29.183 11.321 0.624 
D.sub.11 
12.653 12.453 12.653 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.440 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.411 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.290, 
f.sub.2 (F)/f.sub.2 = 1.255, .vertline.f.sub.1 .vertline./ .sqroot. [f(W) 
.multidot. f(T)] = 1.055 
Embodiment 42 
f = 36.5.about.102, FNO. = 2.86.about.5.9, .omega. = 63.3.about.23.6 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -85.106 0.800 1 1.88300 
40.80 
2 35.156 1.538 
3 38.289 3.528 2 1.84666 
23.83 
4 218.963 variable 
5 19.131 8.962 3 1.51742 
52.15 
6 -110.215 1.351 
7 .infin.(diaphragm) 
0.800 
8 25.705 5.581 4 1.56965 
49.39 
9 -25.120 0.800 5 1.84666 
23.83 
10 47.428 3.919 
11 .infin.(diaphragm) 
variable 
12 56.689 7.728 6 1.72825 
28.32 
13 -14.124 0.800 7 1.88300 
40.80 
14 -545.329 6.809 
15 -12.528 0.800 9 1.51728 
69.68 
16 -35.185 
Aspherical surfaces 
Eighth face 
K = -1.086781, A = -7.694750E-6, 
B = -7.990350E-8, C = -1.269480E-10, 
D = -3.567750E-12 
Fifteenth face 
K = -0.718346, A = -2.065820E-5, 
B = 2.539640E-8, C = -7.606460E-10, 
D = 2.968370E-12 
Variable amounts 
f 36.5 61.156 102.0 
D.sub.4 27.651 10.857 0.800 
D.sub.11 
11.932 11.832 11.932 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.447 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f( 
T) = 0.446 
.vertline.f.sub. 2 (R).vertline./f.sub.2 (F) = 1.553, 
f.sub.2 (F)/f.sub.2 = 1.289, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 1.001 
Embodiment 43 
f = 36.5.about.102, FNO. = 2.91.about.5.9, .omega. = 63.3.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -79.300 0.800 1 1.88300 
40.80 
2 30.882 0.804 
3 32.072 4.692 2 1.76182 
26.55 
4 8312.033 variable 
5 19.371 5.138 3 1.51823 
58.96 
6 -110.256 1.657 
7 .infin.(diaphragm) 
0.800 
8 27.310 3.557 4 1.51602 
56.77 
9 -38.223 0.800 5 1.84666 
23.83 
10 81.350 4.431 
11 .infin.(diaphragm) 
variable 
12 175.268 6.711 6 1.69895 
30.05 
13 -11.845 0.800 7 1.88300 
40.80 
14 -93.359 6.106 
15 -10.865 0.800 9 1.49700 
81.61 
16 -29.498 
Aspherical surfaces 
Eighth face 
K = -1.100163, A = -7.715040E-6, 
B = -7.482230E-8, C = 2.277150E-10, 
D = -3.216280E-12 
Fifteenth face 
K = -0.683131, A = -2.921990E-5, 
B = 9.162650E-8, C = -2.548350E-9, 
D = 8.628930E-12 
Variable amounts 
f 36.501 61.30 102.009 
D.sub.4 30.306 11.851 0.800 
D.sub.11 
12.226 12.126 12.226 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.457 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f( 
T) = 0.421 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.090, 
f.sub.2 (F)/f.sub.2 = 1.172, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 1.069 
Embodiment 44 
f = 36.5.about.102, FNO. = 2.9.about.5.9, .omega. = 63.5.about.23.6 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -85.138 0.887 1 1.83400 
37.34 
2 28.026 0.853 
3 29.944 4.583 2 1.84666 
23.83 
4 169.050 variable 
5 18.918 6.622 3 1.48749 
70.44 
6 -87.225 2.089 
7 .infin.(diaphragm) 
0.800 
8 25.961 3.318 4 1.54814 
45.82 
9 -49.591 0.138 
10 -41.883 0.800 5 1.84666 
23.83 
11 59.536 5.669 
12 .infin.(diaphragm) 
variable 
13 137.981 7.042 6 1.68893 
31.16 
14 -13.085 2.279 7 1.88300 
40.80 
15 -84.900 7.786 
16 -12.568 0.800 9 1.49700 
81.61 
17 -36.562 
Aspherical surfaces 
Eighth face 
K = -1.182221, A = -7.870754E-6, 
B = -7.371219E-8, C = 8.003773E-11, 
D = -4.319129E-12 
Sixteenth face 
K = -0.730490, A = -1.862161E-5, 
B = 8.064080E-8, C = -1.216524E-9, 
D = 3.255338E-12 
Variable amounts 
f 36.499 61.424 101.996 
D.sub.4 29.385 11.372 0.585 
D.sub.12 
10.795 10.595 10.795 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.460 
[f.sub. 1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f 
(T) = 0.435 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.298, 
f.sub.2 (F)/f.sub.2 = 1.227, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 1.047 
Embodiment 45 
f = 36.5.about.102, FNO. = 2.85.about.5.89, .omega. = 63.4.about.23.6 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -83.270 0.800 1 1.88300 
40.80 
2 35.360 1.583 
3 38.701 3.520 2 1.84666 
23.83 
4 238.279 variable 
5 19.134 8.212 3 1.50378 
66.89 
6 -144.780 1.709 
7 .infin.(diaphragm) 
0.800 
8 27.612 5.993 4 1.54072 
47.20 
9 -30.027 0.100 
10 -29.479 0.800 5 1.84666 
23.83 
11 70.640 3.433 
12 .infin.(diaphragm) 
variable 
13 61.406 7.707 6 1.69895 
30.05 
14 -14.007 0.800 7 1.88300 
40.80 
15 -206.074 6.418 
16 -12.759 0.800 9 1.49700 
81.61 
17 - 41.783 
Aspherical surfaces 
Eighth face 
K = -1.403890, A = -9.278020E-6, 
B = -8.577710E-8, C = 9.345540E-11, 
D = -2.707970E-12 
Sixteenth face 
K = -0.736120, A = -1.815330E-5, 
B = 1.581560E-8, C = -5.265050E-10, 
D = 2.489460E-12 
Variable amounts 
f 36.5 61.356 101.996 
D.sub.4 27.625 10.847 0.800 
D.sub.12 
12.701 12.501 12.701 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.443 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f( 
T) = 0.441 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.423, 
f.sub.2 (F)/f.sub.2 = 1.286, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 1.004 
Embodiment 46 
f = 36.5.about.102, FNO. = 2.9.about.5.9, .omega. = 63.4.about.23.5 
i Ri Di j Nj .nu.j 
______________________________________ 
1 -83.380 0.800 1 1.88300 
40.80 
2 33.027 1.073 
3 34.906 4.360 2 1.78472 
25.70 
4 647.228 variable 
5 19.178 6.721 3 1.51680 
64.20 
6 -187.184 1.664 
7 .infin.(diaphragm) 
0.800 
8 30.373 3.563 4 1.51742 
52.15 
9 -31.353 0.100 
10 -32.321 0.800 5 1.84666 
23.83 
11 152.357 6.000 
12 .infin.(diaphragm) 
variable 
13 276.854 7.042 6 1.69895 
30.05 
14 -11.945 0.800 7 1.88300 
40.80 
15 -86.726 6.101 
16 -11.369 0.800 9 1.49700 
81.61 
17 -31.513 
Aspherical surfaces 
Eighth face 
K = -1.601750, A = -9.927140E-6, 
B = -8.102590E-8, C = 1.170720E-10, 
D = -2.498730E-12 
Sixteenth face 
K = -0.709399, A = -2.297340E-5, 
B = 5.850550E-8, C = -1.521790E-9, 
D = 6.285460E-12 
Variable amounts 
f 36.504 61.617 107.032 
D.sub.4 30.402 11.879 0.800 
D.sub.12 
11.287 11.087 11.287 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f( 
T) = 0.454 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f( 
T) = 0.416 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.072, 
f.sub.2 (F)/f.sub.2 = 1.193, .vertline.f.sub.1 .vertline./ .sqroot. 
[f(W) .multidot. f(T)] = 1.073 
______________________________________ 
The above Embodiments 41 to 46 relate to the nineteenth lens structure of 
the present invention. 
FIG. 163 shows a lens arrangement in the Embodiment 41 at the wide angle 
end of the zoom lens. FIGS. 169, 170 and 171 respectively show aberration 
diagrams with respect to the Embodiment 41 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 164 shows a lens arrangement in the Embodiment 42 at the wide angle 
end of the zoom lens. FIGS. 172, 173 and 174 respectively show aberration 
diagrams with respect to the Embodiment 42 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 165 shows a lens arrangement in the Embodiment 43 at the wide angle 
end of the zoom lens. FIGS. 175, 176 and 177 respectively show aberration 
diagrams with respect to the Embodiment 43 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 166 shows a lens arrangement in the Embodiment 44 at the wide angle 
end of the zoom lens. FIGS. 178, 179 and 180 respectively show aberration 
diagrams with respect to the Embodiment 44 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 167 shows a lens arrangement in the Embodiment 45 at the wide angle 
end of the zoom lens. FIGS. 181, 182 and 183 respectively show aberration 
diagrams with respect to the Embodiment 45 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
FIG. 168 shows a lens arrangement in the Embodiment 46 at the wide angle 
end of the zoom lens. FIGS. 184, 185 and 186 respectively show aberration 
diagrams with respect to the Embodiment 46 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens. 
______________________________________ 
Embodiment 47 
f = 36.5.about.102, FNO. = 2.90.about.5.9, .omega. = 63.4.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -83.380 0.800 1 1.88300 
40.80 
2 33.027 1.073 
3 34.906 4.360 2 1.78472 
25.70 
4 647.228 variable 
5 19.178 6.721 3 1.51680 
64.20 
6 -187.184 1.664 
7 .infin.(diaphragm) 
0.800 
8 30.373 3.563 4 1.51742 
52.15 
9 -31.353 0.100 
10 -32.321 0.800 5 1.84666 
23.83 
11 152.357 variable 
12 .infin.(diaphragm) 
variable 
13 276.854 7.042 6 1.69895 
30.05 
14 -11.945 0.800 7 1.88300 
40.80 
15 -86.726 6.101 
16 -11.369 0.800 9 1.49700 
81.61 
17 -31.513 
Aspherical surfaces 
Eighth face 
K = -1.601750, A = -9.927140E-6, 
B = -8.102590E-8, C = 1.170720E-10, 
D = -2.498730E-12 
Sixteenth face 
K = -0.709399, A = -2.297340E-5, 
B = 5.850550E-8, C = -1.521790E-9, 
D = 6.285460E-12 
Variable amounts 
f 36.504 61.030 102.032 
D.sub.4 
30.402 11.879 0.800 
D.sub.11 
6.000 16.287 16.287 
D.sub.12 
11.287 1.000 1.000 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.454 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.416 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.072, f.sub.2 (F)/f.sub.2 
= 1.193, 
.vertline.f.sub.1 .vertline..sqroot.[f(W) .multidot. f(T)] = 1.073 
Embodiment 48 
f = 61.6, FNO. = 4.06, .omega. = 37.8 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -83.380 0.800 1 1.88300 
40.80 
2 33.027 1.073 
3 34.906 4.360 2 1.78472 
25.70 
4 647.228 variable 
5 19.178 6.721 3 1.51680 
64.20 
6 -187.184 1.664 
7 .infin.(diaphragm) 
0.800 
8 30.373 3.563 4 1.51742 
52.15 
9 -31.353 0.100 
10 -32.321 0.800 5 1.84666 
23.83 
11 152.357 variable 
12 .infin.(diaphragm) 
variable 
13 276.854 7.042 6 1.69895 
30.05 
14 -11.945 0.800 7 1.88300 
40.80 
15 -86.726 6.101 
16 -11.369 0.800 9 1.49700 
81.61 
17 -31.513 
Aspherical surfaces 
Eighth face 
K = -1.601750, A = -9.927140E-6, 
B = -8.102590E-8, C = 1.170720E-10, 
D = -2.498730E-12 
Sixteenth face 
K = -0.709399, A = -2.297340E-5, 
B = 5.850550E-8, C = -1.521790E-9, 
D = 6.285460E-12 
Variable amounts 
f 61.617 
D.sub.4 
11.879 
D.sub.11 
16.087 
D.sub.12 
1.000 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.454 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.416 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.072, f.sub.2 (F)/f.sub.2 
= 1.193, 
.vertline.f.sub.1 .vertline./.sqroot.[f(W) .multidot. f(T)] = 1.073 
______________________________________ 
The above Embodiments 47 and 48 relate to the twentieth lens structure of 
the present invention. Concretely, in the Embodiment 47, the front and 
rear lens groups in the second lens group are fixedly disposed and a 
second diaphragm is moved in the lens structure of the above Embodiment 
46. In the Embodiment 48, the second diaphragm is moved in the lens 
structure of the Embodiment 46. 
FIG. 187 shows an aberration diagram at an intermediate focal length of the 
zoom lens in the Embodiment 47. FIG. 188 shows an aberration diagram at 
the telescopic end of the zoom lens in the Embodiment 47. 
FIG. 189 shows an aberration diagram at an intermediate focal length of the 
zoom lens in the Embodiment 48. 
FIGS. 190 to 195 respectively show comparative aberration diagrams with 
respect to the Embodiments 41 to 46. Namely, FIGS. 190 to 195 respectively 
correspond to the Embodiments 41 to 46. FIGS. 190 to 195 respectively show 
aberrations in the lens structures of the Embodiments 41 to 46 at an 
intermediate focal length of the zoom lens when the zooming operation is 
integrally performed by the front and rear lens groups in the second lens 
group. When FIGS. 190 to 195 are respectively compared with the 
corresponding aberration diagrams of FIGS. 41 to 46, it is clearly 
understood that the aberrations in the lens structures of the Embodiments 
41 to 46 are improved in comparison with a case in which the front and 
rear lens groups are integrally displaced by changing the distance between 
the front and rear lens groups of the second lens group in the zooming 
operation of the zoom lens. 
______________________________________ 
Embodiment 49 
f = 36.0.about.102, FNO. = 2.61.about.5.83, .omega. = 64.1.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -79.579 1.000 1 1.83500 
42.98 
2 36.942 2.235 
3 41.644 4.062 2 1.84666 
23.83 
4 178.771 variable 
5 18.505 8.169 3 1.56873 
63.10 
6 -3634.191 0.801 
7 21.171 3.948 4 1.51728 
69.68 
8 -298.584 0.613 
9 -72.611 1.764 5 1.87800 
38.20 
10 13.173 7.160 6 1.48749 
70.44 
11 -13.964 1.000 
12 .infin.(diaphragm) 
variable 
13 -36.430 3.510 7 1.84666 
23.83 
14 -17.118 1.400 
15 -16.109 1.000 8 1.75500 
52.32 
16 -43.667 4.701 
17 -14.418 1.000 9 1.75500 
52.32 
18 -35.916 
Aspherical surfaces 
Seventh face 
K = -0.841420, A = -1.144740E-5, 
B = -7.672070E-8, C = -2.375020E-10, 
D = 2.531780E-13 
Seventeenth face 
K = -0.553246, A = -6.534560E-6, 
B = 8.005760E-9, C = -2.753670E-10, 
D = 4.413500E-13 
Variable amounts 
f 36.001 62.001 
102.002 
D.sub.4 
27.281 10.119 
0.800 
.infin. 
D.sub.12 
13.355 13.355 
13.355 
1.0m D.sub.12 
15.834 16.092 
16.738 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.425 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.425 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.030, f.sub.2 (F)/f.sub.2 
= 1.231, 
.vertline.f.sub.1 .vertline./.sqroot.[f(W) .multidot. f(T)] = 1.000 
m.sub.2 (RW) = 1.281 
Embodiment 50 
f = 36.0.about.102, FNO. = 3.82.about.5.83, .omega. = 64.1.about.23.5 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -76.723 1.000 1 1.83500 
42.98 
2 37.775 1.804 
3 41.790 3.982 2 1.84666 
23.83 
4 185.630 variable 
5 18.345 7.673 3 1.56883 
56.04 
6 699.823 0.800 
7 21.379 3.962 4 1.51728 
69.68 
8 -126.917 0.446 
9 -67.099 1.000 5 1.87800 
38.20 
10 13.329 7.307 6 1.48749 
70.44 
11 -32.298 variable 
12 .infin.(diaphragm) 
variable 
13 -35.181 5.687 7 1.78470 
26.06 
14 -14.618 1.000 8 1.52300 
60.40 
15 -29.093 4.796 
16 -12.870 1.000 9 1.84750 
43.03 
17 -51.522 
Aspherical surfaces 
Seventh face 
K = -0.861691, A = -1.181800E-5, 
B = -5.935980E-8, C = -3.334560E-10, 
D = 1.052620E-12 
Sixteenth face 
K = -0.614002, A = -7.001330E-6, 
B = -8.172220E-9, C = -2.511720E-10, 
D = 3.695480E-13 
Variable amounts 
f 36.001 62.001 
102.003 
D.sub.4 
26.728 9.924 
0.800 
.infin. 
D.sub.12 
14.360 7.916 
2.000 
1.0m D.sub.12 
17.277 10.872 
5.573 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.404 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.404 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 1.021, f.sub.2 (F)/f.sub.2 
= 1.263, 
.vertline.f.sub.1 .vertline./.sqroot.[f(W) .multidot. f(T)] = 1.000 
m.sub.2 (RW) = 1.253 
Embodiment 51 
f = 36.0.about.102, FNO. = 2.59.about.5.83, .omega. = 64.6.about.23.4 
i Ri Di j Nj .upsilon.j 
______________________________________ 
1 -62.449 1.000 1 1.88300 
40.80 
2 39.714 0.844 
3 41.598 4.890 2 1.84666 
23.83 
4 1048.754 variable 
5 20.355 8.725 3 1.51728 
69.68 
6 -131.935 0.800 
7 22.740 3.957 4 1.49700 
81.61 
8 -74.614 0.632 
9 -42.562 1.000 5 1.87800 
38.20 
10 18.870 10.282 6 1.48749 
70.44 
11 -21.821 variable 
12 .infin.(diaphragm) 
variable 
13 -129.987 3.496 7 1.84666 
23.83 
14 -18.338 0.100 
15 -21.509 1.000 8 1.88300 
40.80 
16 -1737.540 6.969 
17 -10.739 1.000 9 1.75500 
52.30 
18 -31.080 
Aspherical surfaces 
Fifth face 
K = 0.029427, A = 3.401320E-6, 
B = 4.986230E-9, C = -1.303190E-11, 
D = -1.927200E-15 
Seventh face 
K = -1.311644, A = -1.798800E-5, 
B = -8.672390E-8, C = -6.906760E-10, 
D = 2.391230E-12 
Seventeenth face 
K = -0.237038, A = 3.817170E-6, 
B = 1.463820E-7, C = -1.666070E-9, 
D = 8.337830E-12 
Variable amounts 
F 36.000 61.999 
101.997 
D.sub.4 
26.716 9.920 0.800 
D.sub.11 
1.000 7.000 8.816 
.infin. 
D.sub.12 
8.816 2.816 1.000 
1.0m D.sub.12 
10.115 4.417 2.999 
Values of conditional formulas 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(W)) - (f(W)/f.sub.1)}]/f(T) 
= 0.385 
[f.sub.1 + f.sub.2 .multidot. {2 - (f.sub.1 /f(T)) - (f(T)/f.sub.1)}]/f(T) 
= 0.378 
.vertline.f.sub.2 (R).vertline./f.sub.2 (F) = 0.757, f.sub.2 (F)/f.sub.2 
= 1.215, 
.vertline.f.sub.1 .vertline./.sqroot.[f(W) .multidot. f(T)] = 1.014 
m.sub.2 (RW) = 1.460 
______________________________________ 
The above Embodiments 49 to 51 relate to the twenty-first and twenty-second 
lens structures of the present invention. 
FIG. 196 shows a lens arrangement in the Embodiment 49 at the wide angle 
end of the zoom lens. FIGS. 199, 200 and 201 respectively show aberration 
diagrams with respect to the Embodiment 49 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens when the distance from the zoom lens to a 
photographed object is infinite. FIGS. 202, 203 and 204 respectively show 
aberration diagrams with respect to the Embodiment 49 at the wide angle 
end of the zoom lens, an intermediate focal length of the zoom lens and 
the telescopic end of the zoom lens when the distance from the zoom lens 
to the photographed object is set to 1 m. 
FIG. 197 shows a lens arrangement in the Embodiment 50 at the wide angle 
end of the zoom lens. FIGS. 205, 206 and 207 respectively show aberration 
diagrams with respect to the Embodiment 50 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens when the distance from the zoom lens to a 
photographed object is infinite. FIGS. 208, 209 and 210 respectively show 
aberration diagrams with respect to the Embodiment 50 at the wide angle 
end of the zoom lens, an intermediate focal length of the zoom lens and 
the telescopic end of the zoom lens when the distance from the zoom lens 
to the photographed object is set to 1 m. 
FIG. 198 shows a lens arrangement in the Embodiment 51 at the wide angle 
end of the zoom lens. FIGS. 211, 212 and 213 respectively show aberration 
diagrams with respect to the Embodiment 51 at the wide angle end of the 
zoom lens, an intermediate focal length of the zoom lens and the 
telescopic end of the zoom lens when the distance from the zoom lens to a 
photographed object is infinite. FIGS. 214, 215 and 216 respectively show 
aberration diagrams with respect to the Embodiment 51 at the wide angle 
end of the zoom lens, an intermediate focal length of the zoom lens and 
the telescopic end of the zoom lens when the distance from the zoom lens 
to the photographed object is set to 1 m. 
As mentioned above, in accordance with the present invention, it is 
possible to provide a novel zoom lens having a high variable 
magnification. 
As mentioned above, with respect to this zoom lens, refracting power of the 
second lens group can be increased while the distance between the first 
and second lens groups is secured. Accordingly, the entire length of the 
zoom lens can be reduced and refracting power of the front lens group in 
the second lens group can be reduced so that an F-number of the zoom lens 
can be reduced. 
Many widely different embodiments of the present invention may be 
constructed without departing from the spirit and scope of the present 
invention. It should be understood that the present invention is not 
limited to the specific embodiments described in the specification, except 
as defined in the appended claims.