Wide range focusing camera

In a wide range focusing camera, a cooperating engagement members are provided in moveable parts of a focusing mechanism and an aperture opening selecting mechanism so as to force the latter into selecting a smaller one of the aperture opening areas when the focusing mechanism is actuated into moving the lens to the position suitable for a close range shot. At the same time, a strobe light is enabled. Thus, the focal depth can be increased, and a clear picture of a close range object can be taken without regard to the condition under which the object is placed in relation with the surrounding objects. Also, a three-dimensional object having a depth can be photographed at close range with a satisfactory result. Because a number of settings required for such close-up shots are instantaneously set either manually by hand or automatically by an auto-focusing mechanism, it is possible even for an inexperienced photographer to take clear pictures of objects at close range.

TECHNICAL FIELD 
The present invention relates to a wide range focusing camera which can 
take clear pictures of objects over a wide distance range, and in 
particular to a wide range focusing camera which can take clear pictures 
of objects at extremely close range. 
BACKGROUND OF THE INVENTION 
Conventionally, a camera, in particular a compact camera, is capable of 
taking clear pictures only when the object is at least approximately one 
meter away. Some of the cameras are equipped with a macro mode which 
allows a clear picture to be taken even when the object is as close as 60 
cm away. However, the pictures which can be obtained by these cameras are 
often unsatisfactory because the surrounding objects which are located in 
front and behind the central objects cannot be properly focused. In 
particular, when the object has a three-dimensional shape, and has a 
depth, it was not possible to achieve a favorable focusing over the entire 
object. Furthermore, it has not been possible with the exception of 
certain specialized cameras to take a clear picture of an object which is 
at an extremely close range, for instance in the distance range of 10 to 
30 cm. 
The difficulty in overcoming these limitations may be attributed to the 
fact that the lens of the camera must travel over a large distance in 
order to cover such a close range as well as an infinitely far range. 
Incorporating the camera with a lens actuating mechanism capable of moving 
the lens over such a large distance in a normal camera has been considered 
impractical from both technical and commercial view points. Furthermore, 
the lenses of such cameras have not been able to provide a sufficient 
focal depth to allow a three-dimensional object to be photographed at an 
extremely close range. In the case of a compact camera, it is also 
essential that the user is not required to make any complicated 
adjustments. 
BRIEF SUMMARY OF THE INVENTION 
In view of such problems of the prior art, a primary object of the present 
invention is to provide a simple camera which can take clear pictures even 
when the object is as close as only 10 to 30 cm away from the camera 
without sacrificing the capability of the camera to cover the infinitely 
far range. 
A second object of the present invention is to provide a simple camera 
which is capable of taking pictures at a close range while ensuring a 
large focal depth which has hitherto not been available. 
A third object of the present invention is to provide a simple camera which 
is equipped with a macro operative mode and suitable for use by general 
consumers. 
According to the present invention, these and other objects of the present 
invention can be accomplished by providing a wide range focusing camera, 
comprising; a lens moving means for moving a lens of the camera for 
selecting a distance range for a clear photographic shot; an aperture 
opening changing means for changing an aperture opening of the camera; a 
lighting device for illuminating an object of the camera; and a selector 
switch for selecting from a normal operative mode and a super macro 
operative mode; the normal operative mode being defined in a such a way 
that the lens is positioned for a shot at a normal distance range, and the 
aperture opening is selected for a normal shot; the super macro operative 
mode being defined in a such a way that the lens is positioned for a shot 
at a closer distance range which adjoins the normal distance range, the 
lighting device is activated, and the aperture opening is reduced so as to 
be compatible with the activation of the lighting device at the closer 
distance range. Preferably, the selector switch includes a single member 
or two push-buttons which consolidate all the necessary adjustments. 
According to this inventive concept, the aperture opening for the super 
macro operative mode is typically pre-determined. 
Thus, according to the present invention, because a number of settings 
which make the camera suitable for close range photographing can be 
achieved with a single operation, even an inexperienced person can take a 
satisfactory picture of an object at a close range. In particular, by 
reducing the aperture opening when the super macro mode is selected, the 
focal depth can be increased, and a clear picture of the close range 
object can be taken without regard to the condition under which the object 
is placed in relation with the surrounding objects. Hence, a 
three-dimensional object having a depth can be photographed with a 
satisfactory result. By enabling a lighting device such as a strobe light 
or a flash bulb when the super macro mode is selected, the small aperture 
opening area that is required for increasing the focal depth can be 
selected without causing any insufficient photographic exposure of the 
photographic film. Although the present invention was contemplated for 
application as photographic cameras, it can be equally applicable to 
digital cameras having a CCD image sensor at the focal plane. To allow the 
camera to truly cover the far and near ranges without any break, the 
normal distance range and the closer distance range preferably overlap 
each other. 
The control member may be actuated not only manually but also by a powered 
motor. In the latter case, the powered motor may be actuated according to 
an output signal from a range sensor so that the focusing is automatically 
adjusted, and the macro mode may be automatically selected when the object 
to be photographed is detected to be at a sufficiently close range. 
The aperture opening area may be determined by any known mechanism, for 
instance by a plurality of aperture control blades. Because the aperture 
opening is required to be fairly small when the super macro mode is 
selected, the aperture opening may be determined by a moveable plate 
member having a plurality of aperture openings formed therein and adapted 
to be selectively moved so as to place a selected one of the aperture 
openings in an optical axial line of the lens, or by a combination of a 
plurality of aperture control blades, and a moveable plate member having 
an aperture opening formed therein and adapted to be selectively moved so 
as to place the aperture opening in an optical axial line of the lens. 
To cover an even closer range, the selector switch may additionally allow 
selection of an ultra super macro operative mode which is defined in a 
such a way that the lens is positioned for an even closer distance range 
which adjoins the super macro distance range, the lighting device is 
activated, and the aperture opening is reduced so as to be compatible with 
the activation of the lighting device at the even closer distance range. 
In this case also, the aperture opening may be pre-determined, and the 
closer distance range and the even closer distance range may overlap each 
other. 
In more concrete terms, the present invention provides a wide range 
focusing camera, comprising: a focusing mechanism for selectively moving a 
lens of the camera to at least two different positions which are suitable 
for a relatively long distance shot and a relatively short distance shot, 
respectively; an aperture opening selecting mechanism for defining at 
least two different aperture opening areas; a control member for actuating 
the focusing mechanism so as to move the lens to a selected one of the two 
positions; and cooperating engagement members provided in moveable parts 
of the focusing mechanism and the aperture opening selecting mechanism so 
as to move the aperture opening selecting mechanism into selecting a 
smaller one of the aperture opening areas when the focusing mechanism is 
actuated into moving the lens to the position suitable for a close range 
shot. 
So as not to interfere with the existing mechanism for selecting the 
settings which are suitable for the normal operative mode, a lost motion 
mechanism may be incorporated in the mechanism for coordinating the 
movement of the focusing mechanism and the aperture opening selecting 
mechanism so that the aperture opening selecting mechanism may select a 
smaller one of the aperture opening areas without interfering with a 
member for selecting an aperture opening area when the lens is at the 
position suitable for a long range shot. 
When a fully automated mode selection is desired or a motor powered mode 
selection is desired, the present invention may provide a wide range 
focusing camera, comprising: a focusing mechanism for selectively moving a 
lens of the camera to at least two different positions which are suitable 
for a relatively long range shot and a relatively short range shot, 
respectively; an aperture opening selecting mechanism for defining at 
least two different aperture opening areas; a first motor for actuating 
the focusing mechanism; a second motor for actuating the aperture opening 
selecting mechanism; and an electric circuit for coordinating the second 
motor with the first motor so that the aperture opening selecting 
mechanism may select a smaller one of the aperture opening areas when the 
lens is moved to the position suitable for a relatively short range shot. 
In this case, two electric motors are required, but the mechanism for 
coordinating the focusing mechanism and the aperture opening selecting 
mechanism may be simplified. Also, the camera may be equipped with an 
automatic focusing mechanism which actuates the first motor according to a 
signal from a range sensor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 is a front view of a compact camera to which the present invention 
is applied. A lens 2 is placed centrally in the front portion of a camera 
body 1, and is surrounded by an ornamental ring 3. An operation mode 
selection lever 4 serving as means for moving the lens projects integrally 
and radially from the ornamental ring 3. 
The operation modes include a non-operative mode (O) for closing the lens 
with a barrier (not shown in the drawings), a normal operative mode (N) 
for taking pictures of objects at a distance of 1.0 m or further, a super 
macro operative mode (SM) for taking pictures of objects in a distance 
range of 30 cm to 1.0 m, and an ultra super macro operative mode (USM) for 
taking pictures of objects in a distance range of 10 cm to 30 cm. Each one 
of these operation modes can be selected by turning the ornamental ring 3 
to a corresponding one of four angular positions thereof with the mode 
selection lever 4. 
The internal structure of this camera is described in the following with 
reference to FIGS. 2 and 3. A cam tube 5 is fixedly secured inside the 
camera body 1 coaxially with respect to the ornamental ring 3. A retaining 
tube 6 retaining the lens 2 therein is coaxially received in the cam tube 
5 in an axially slidable manner, and is integrally attached to the 
ornamental ring 3 having the mode selection lever 4 integrally projecting 
therefrom so that the retaining tube 6 turns integrally with the mode 
selection lever 4. 
A cam pin 6a projecting integrally from the outer circumferential surface 
of the retaining tube 6 is engaged by a spiral cam slot 5a formed in the 
outer wall of the cam tube 5. As a result, the retaining tube 6 travels 
axially as the retaining tube 6 is turned with the cam pin 6a engaged by 
the cam slot 5a. The spiral lead of the cam slot 5a is determined such 
that the forward movement of the retaining tube 6 accelerates as the lever 
4 is turned from the normal operative mode position to the ultra super 
macro mode position. This is due to the fact that the displacement of the 
focal point progressively increases as the distance to the object 
diminishes when a lens of a fixed focal length is used. Thus, by turning 
the lever 4, the lens 2 is axially moved so as to define a focal point on 
a film surface according to the distance to the object. 
An aperture control mechanism or a variable aperture mechanism is 
incorporated in the retaining tube 6. The aperture control mechanism may 
be of a conventional type which includes a plurality of aperture control 
blades 7a. The aperture control blades 7a are jointly engaged by a ring 
member 7b which is coaxially received in the retaining tube 6 in such a 
manner that the overlapping state of the aperture control blades 7a is 
changed in synchronism with the rotation of the ring member 7b, and a 
central opening 7c defined by the aperture control blades 7a is varied in 
diameter. The ring member 7b can move axially jointly with the retaining 
tube 6. 
A shutter 10 is placed between the aperture control mechanism and the film 
surface as indicated by the imaginary lines in FIG. 3. The camera body 1 
further includes a shutter button 11, and a strobe light 12. 
FIGS. 4 to 7 are conceptual views for illustrating the mode of operation of 
the embodiment illustrated in FIGS. 1 to 3. The shapes of the various 
parts and the geometric relationships between the various components are 
modified for the ease of illustration, and are not intended to be 
accurate. 
In this embodiment, the ring member 7b is integrally provided with an 
engagement piece 7d extending radially outwardly therefrom, and the inner 
circumferential surface of the retaining tube 6 is provided with an 
engagement arm 6b which extends radially inwardly therefrom, and engages 
the engagement piece 7d. The ring member 7b is further integrally provided 
with an actuating arm 7e which engages an aperture control lever 8 for 
changing the aperture opening in the normal operative mode, and a tension 
coil spring 9 is connected between the actuating arm 7e and a fixed part 
of the camera body 1 so that the ring member 7b is urged in the direction 
to increase the opening of the aperture control mechanism. 
The aperture control lever 8 engages the actuating arm 7e against the 
biasing force of the spring 9. The position of the aperture control lever 
8 is adjusted by a motor or a solenoid according to a signal from a light 
sensor not shown in the drawing, or is simply set manually by the user of 
the camera. 
The mode of operation is described with the following with reference to 
FIGS. 4 to 7. When an object at 1.0 m or further is to be photographed by 
this camera, the aperture control mechanism is set at a value which is 
suitable for taking a picture in a relatively bright surrounding without 
the aid of the strobe light. When the mode selection lever 4 is at the 
normal operative position (N), the engagement arm 6b is out of engagement 
from the engagement piece 7d as illustrated in FIG. 4. 
In this normal operative mode, when a picture is to be taken under an 
insufficiently lighted condition, for instance after dark or indoors, the 
strobe light 12 is enabled either manually or by the light sensor which 
has detected the insufficiency of lighting. The aperture control lever 8 
is then actuated either automatically or manually in the direction 
indicated by arrow B in FIG. 4 until the lever reaches a prescribed 
position. As a result, the actuating arm 7e follows the movement of the 
aperture control lever. 8 under the spring force of the tension coil 
spring 9, and the ring member 7b turns in counter-clockwise direction in 
the drawing so as to place the aperture opening 7c in a wide open state as 
illustrated in FIG. 5. Thus, in the normal operative mode, either one of 
the states illustrated in FIGS. 4 and 5 are appropriately selected 
depending on the amount of the surrounding light, and a picture is taken 
by pressing the shutter button 10. It is also possible that the aperture 
control lever 8 can take a selected number of positions or any continually 
selectable position between the two states illustrated in FIGS. 4 and 5 
depending on the amount of light detected by the light sensor, or 
according to a manual selection. 
When the super macro mode (SM) is desired to be selected for taking a 
picture of an object in a distance range of 30 cm to 1.0 m, the operation 
mode selection lever 4 is turned in the direction indicated by arrow C in 
FIG. 4 to the super macro mode position (SM). This causes the lens 2 to be 
pushed forward owing to the cam pin 6a moving along the cam slot 5a while 
the engagement arm 6b which is integral with the retaining tube 6 moves in 
the direction indicated by arrow D in FIG. 6 to the position illustrated 
in FIG. 6. The aperture control blades 7a thus move in the direction to 
reduce the aperture opening 7c, for instance to 1.2 mm in diameter. For 
instance by producing a suitable frictional resistance by the mutual 
fitting of the retaining tube 6 and the cam tube 5, it is possible to keep 
the retaining tube 6 stationary in the illustrated state in spite of the 
spring force of the tension coil spring 9. If necessary, a suitable detent 
mechanism may be used to keep the mode selection lever 4 stationary at 
each selected position. 
When this super macro mode was actually defined for a 35 mm camera having a 
focal length of 35 mm, the focal setting was set for an object which is 
located 70 cm away from the camera, the aperture control was selected at 
F22, and the strobe light 12 was enabled. In this super macro mode, it was 
possible to take a satisfactory picture of an object in the distance range 
of 30 cm to 1.2 m. Thus, this mode enables the taking of a clear picture 
of stationary objects, fruits, paintings, insects, flowers, china ware and 
so forth at a suitable scale. 
When the mode selection lever 4 is turned further in the direction 
indicated by arrow D in FIG. 6 to the ultra super macro position (USM), 
the retaining tube 6 is turned by a prescribed angle until the engagement 
arm 6b moves to the position illustrated in FIG. 7. The aperture opening 
7c is further reduced in diameter, for instance to 0.7 mm. The aperture 
control position is set at F44. In this ultra super macro mode (USM), the 
lens 2 is pushed to a front most position to thereby place the lens 2 
suitable for forming an image of an object 17 cm away from the camera on 
the film surface. 
This ultra super macro mode (USM) was actually applied to the camera 
mentioned in association with the super macro mode (SM). This setting 
allowed a clear picture to be taken of an object which is in a distance 
range of 10 cm to 40 cm. In particular, when the object is placed 10 cm 
away from the camera, the image of the object on a regular size photograph 
print was approximately 1.7 times the actual size. Thus, this mode allowed 
the object to be recorded in an enlarged scale without any enlargement or 
trimming. 
These macro modes are each defined by selecting a set of conditions such as 
the lens position, the aperture control position and the enabling of the 
strobe light. These settings can be mechanically achieved by turning of a 
mode selection lever as described above, but can be also electronically 
achieved by incorporating the camera with a CPU and a motor actuator. 
The aperture control blades used in some of the compact cameras may not be 
suitable for achieving small aperture openings at high precision. This 
problem can be avoided by providing a plate member 13 having small 
openings 13a and 13b for the super macro mode and the ultra super macro 
mode therein, and placing the plate member 13 before or after the aperture 
control blades 7a. The plate member 13 in the embodiment illustrated in 
FIG. 8 is pivotally supported at a point 13c so that each of the small 
openings 13a and 13b may be aligned with the aperture opening 7c of the 
aperture control mechanism, and its pivotal movement is synchronized with 
the rotation of the retaining tube 6 by meshing of a sector gear 13d 
integrally formed in the plate member 13 with an internal gear 6c formed 
in the retaining tube 6 via an idle gear 14. 
According to the embodiment illustrated in FIG. 8, the plate member 13 is 
in a retracted position to be placed out of the way from the aperture 
control blades 7a in the normal operative mode as indicated by the 
imaginary lines. When the super macro mode (SM) is selected, the plate 
member 13 pivots in the direction indicated by arrow E to the position 
indicated by solid lines in FIG. 8, and the aperture opening is determined 
by the relatively larger one of the small openings 13a of the plate member 
13 which is aligned with the optical axial line. Similarly, when the ultra 
super macro mode (USM) is selected, the extremely small opening 13b is 
aligned with the optical axial line instead of the small opening 13a. 
When the aperture control blades 7a are employed for determining the 
aperture opening 7c, it is possible to continually vary the aperture 
opening not only for the normal operative mode but also for the macro 
modes, instead of defining a limited number of settings for step-wise 
selection. Likewise, it is also possible to allow the focusing to be 
continually set not only in the normal operative mode but also over the 
entire range including both the normal operative mode and the macro modes. 
If desired, the plate member may be provided with three or more openings 
so that the aperture control blades 7a may be eliminated, and a desired 
number of aperture sizes can be achieved. It is also possible to have only 
the super macro mode in addition to the normal operative mode, instead of 
having two macro modes. 
According to the present invention, it is possible to achieve a large focal 
depth, and a clear picture can be therefore taken at all times without 
regard to the nature of the object which is to be photographed simply by 
selecting the operating mode of the camera. This also in no way interferes 
with the photographing of objects which are located from an intermediate 
range to an infinitely far range as long as an appropriate lighting 
condition is available. 
The following is a description of how the super macro operative mode may be 
designed. 
As mentioned earlier, as the mode selection lever 4 is moved from the 
normal operative mode (N) to the super and ultra macro operative modes (SM 
and USM), it is necessary to increase the possible range of the forward 
travel of the lens because, for a lens of a given focal length, as the 
distance to the photographic object decreases, the increase ratio of the 
movement of the focal point of the lens progressively increases. 
Referring to FIG. 9, an incident light beam from an infinitely far point 
which passes through a lens converges on an intrinsic focal point (film 
surface). However, when the incident light beam from a finite distance 
passes through the lens, it converges on a point which is behind the 
intrinsic focal point by a distance a. Thus, the focal point recedes as 
the distance between the camera and the photographic object decreases. In 
a camera, the lens is pushed forward as the distance to the object 
decreases so as to place the focal point always on the film surface. 
This is further described with reference to FIGS. 10 to 13 where a lens 
having a focal length of 25 mm (f=25 mm) and ISO 100 photographic film are 
used. However, as will be readily appreciated by a person skilled in the 
art, the same principle is applicable also when different lenses and 
different photographic films are used. 
In the graph of FIG. 10, the horizontal coordinate represents the distance 
between the camera and the photographic object (range) and the vertical 
coordinate represents the travel a of the focal point away from the 
intrinsic focal point. As the graph clearly indicates, as the distance 
between the camera and the photographic object decreases, the 
corresponding travel a of the focal point progressively increases. In 
particular, in the region between the normal operative mode and the super 
macro mode (normally at the distance of approximately 1 m), the travel a 
of the focal point sharply increases. Thus, it becomes necessary to move 
the lens by a significant distance in order to allow the camera to take 
pictures at close range. Such a lens moving mechanism requires a highly 
complex and expensive mechanism. This is one of the reasons why the normal 
cameras are not equipped with the capability to take pictures at close 
range. 
Each lens has a distance range over which an image can be formed on the 
film surface with a tolerable sharpness. The sharpness of the image is 
defined by the size of the circle of least confusion which, in this case, 
is defined at the value of 0.05 mm. Based on this criterion, the graph of 
FIG. 10 shows the depth of focus for four different distances to the 
photographic object. These distances are selected such that the lens 
position is at a mid point of each of the four different travel ranges S1 
to S4. As the distance to the photographic object diminishes, the change 
rate of the travel a of the lens (S1 to S4) progressively increases while 
the depth of focus (H1 to H4) progressively diminishes. 
For instance, when the lens is moved to a mid point of the lens travel 
range S1 or to a position for an object 3.2 m away, the depth of focus 
reaches infinity on the far side, and approximately 1.6 m on the near 
side. When the lens is pushed slightly further out to a position suitable 
for a photographic object 1.3 m away (mid point of range S2), the focal 
depth diminishes as indicated by the distance range H2 or from about 1.0 m 
to 2.0 m. When the lens is further pushed out to a position (mid point of 
range S3) suitable for a photographic object 0.45 m away, the focal depth 
diminishes further, approximately from 0.42 to 0.53 m (H3). When the lens 
is even further pushed out to a position (mid point of range S4) suitable 
for a photographic object which is 0.37 m away, the focal depth diminishes 
even further, approximately from 0.24 to 0.30 m (H4). 
Thus, when the camera is focused to an object at an extremely close range, 
it becomes progressively more difficult to achieve a proper focusing. Even 
if a proper focusing is achieved, the focal depth would be so small that 
any three dimensional object would not be focused as a whole. Also, any 
known auto focusing device is inadequate for a photographic object which 
is no more than 30 cm away from the camera. 
According to the present invention, to resolve this problem, the aperture 
opening is dramatically reduced when the super macro or the ultra super 
macro operative mode is selected for taking a picture of an object at an 
extremely close range. FIG. 11 shows how the focal depth is increased by 
reducing the aperture opening. The three bars at the bottom of the graph 
of FIG. 11 indicate the focal depths when the lens is positioned for an 
object at the distances of 0.2 m, 0.5 m and 1.5 m, respectively, with the 
aperture opening of F5.6. The bar in the middle of the graph indicates the 
focal depth when the lens is positioned for an object at the distance of 
0.5 m with the aperture opening of F22, and the bar at the top of the 
graph indicates the focal depth when the lens is positioned for an object 
at the distance of 0.2 m with the aperture opening of F44. 
From this graph, it can be seen that the range of approximately from 0.1 m 
to infinity can be covered by three different lens positions by 
appropriately reducing the aperture opening. Furthermore, the focal depth 
for each of the lens positions overlaps the adjacent one, and is also so 
large that a satisfactory picture of three dimensional objects can be 
taken at any distance from an extremely close range to infinity. The two 
short bars indicated by dotted lines at the bottom of the graph show that, 
when the aperture opening is not reduced, the focal depths would be so 
small that not only would the three lens positions be inadequate for 
covering a close range without any breaks but also a properly focused 
picture of a three dimensional object cannot be taken at close range. 
According to a conventional camera, the lens position is moved to a 
position suitable for the photographic object, and the shutter speed and 
the aperture opening are selected according to the brightness of the 
object. A lighting device is activated only when the lighting for the 
object is not adequate. Therefore, when the principle of such a 
conventional camera is extended to a camera for a macro picture taking 
mode, there is no linking between the activation of the lighting device 
and the macro picture taking mode, and the dramatic reduction in the focal 
depth renders the camera virtually useless for the intended purpose. 
According to the super macro or the ultra super macro mode embodying the 
present invention, without detecting the distance to the object or the 
brightness of the object, and without changing the shutter speed, the 
lighting device is activated without regard to the surrounding condition. 
Also, the lens position and the dramatically reduced aperture opening are 
predetermined for each selected macro mode. The dramatically reduced 
aperture opening is balanced by the increased brightness of the object 
owing to the activation of the lighting device. The proximity of the 
object from the camera or the lighting device causes an extremely high 
level of brightness of the object, and this allows the dramatic reduction 
in the aperture opening. When the ISO sensitivity of the photographic film 
is 100, for instance, the optimum intensity of the strobe light can be 
computed from the following formula. 
EQU (guide number of the strobe light)/(F value of the lens) 
When the film sensitivity is increased to ISO 200, it is equivalent to 
increasing the aperture opening by one notch. When the film sensitivity is 
increased from ISO 100 to ISO 400, it is equivalent to increasing the 
aperture opening by two notches. It is also known that photographic film 
has a certain latitude which, combined with some adjustment during the 
photographic developing process, provides a tolerance of about three 
notches from the standard value on the brighter side and about two notches 
on the darker side. 
FIG. 12 shows the acceptable reach of the strobe light and the focal depth 
when the lens is positioned for each of ten different distances to the 
photographic object and a corresponding aperture opening is selected. In 
this case, the distances are covered from 0.1 m to 1.0 m by an increment 
of 0.1 m. The white bars each indicate the range of acceptable strobe 
lighting by considering the normal latitude of the photographic film. The 
shaded bars each indicate the range covered by the corresponding focal 
depth. The range covered by both the white bar and the shaded bar for each 
lens position or each aperture opening is the actual range over which a 
satisfactory picture of the object can be taken. 
In practice, the aperture opening and the lens position can be moved 
continually by moving the mode selection lever 4 if such a mechanism is 
incorporated in the camera. Alternatively or additionally, a stepwise 
adjustment of the aperture opening and the lens position may be employed. 
In the illustrated embodiments, the aperture opening and the lens position 
are selected in a stepwise fashion for the convenience of description. 
FIG. 13 shows an example in which the macro operative mode consists of two 
steps. The super macro operative mode which adjoins the normal operative 
mode with some overlap incorporates the lens position for an object at the 
distance of 0.5 m and the aperture opening of F20. The ultra super macro 
operative mode which adjoins the super macro operative mode with some 
overlap incorporates the lens position for an object at the distance of 
0.2 m and the aperture opening of F50. As can be seen from this graph, the 
camera is now capable of covering from the distance of only 0.1 m to 
infinity without any break. 
The design criteria adopted in the illustrated embodiments is a circle of 
least confusion of 0.05 mm which is suitable for achieving high quality 
photographing by normal standard. The strobe light used in the illustrated 
embodiments consisted of an inexpensive strobe light unit incorporated in 
a compact camera, but proved to be adequate for achieving high quality 
photographing results over the entire range of distance. The distance 
between the camera and the photographic object should be measured between 
the object and the film surface, but can be approximated by the distance 
between the front end of the lens and the object. If a higher accuracy is 
desired, the distance between the film surface and the lens may be added 
to the distance between the lens and the object. 
The present invention allows a simple, inexpensive camera to photograph 
objects at close range which, hitherto, has been possible only by an 
experienced photographer using a specialized camera. The modification from 
a conventional camera for manufacturing a camera according to the present 
invention is so minor that almost no increase in cost will be necessary. 
For instance, for a camera having a focal length of 25 mm, the travel of 
the lens required to cover a distance range of 1.0 m to infinity would be 
0.6 to 0.7 mm. The lens travel must be increased to 4.5 to 4.8 mm for the 
camera to be adapted to the close range photographing according to the 
present invention. In the case of a camera having a focal length of 35 mm, 
the required lens travel would be 7 to 8 mm. The inventor has discovered 
that a lens travel of this order can be achieved without requiring any 
major modifications to the conventional inexpensive cameras. The required 
lens travel increases in proportion to the increase in the focal length of 
the lens of the camera. 
The shutter speed may be changed, for instance may be reduced, when a macro 
mode is selected. But, it was confirmed by the inventor that the latitude 
of the commercially available photographic film is so large that a 
satisfactory super macro or ultra super macro photographing is possible 
without changing the shutter speed from that for the normal operative 
mode. In particular, the strobe light has such a short duration of light 
emission that the effective shutter speed is determined by the strobe 
light. The elimination of the need for changing the shutter speed is 
particularly beneficial in reducing the cost of the camera. 
The illustrated embodiments are generally based on the manual selection of 
the operation modes, but it is also possible to automate the operation 
mode selection to a desired extent. For instance, as illustrated in FIG. 
14, the camera body 1 may be incorporated with a super macro button 15 for 
selecting the super macro mode (SM) and an ultra super macro mode button 
16 for selecting the ultra super macro mode (USM) at an upper part 
thereof. An additional button may also be provided on the camera body for 
selecting between the non-operative mode (O) and the normal operative mode 
(N). 
When a close range photographing is desired, either one of the macro push 
buttons 15 or 16 is pressed. This causes the cam tube 5 to be turned by a 
prescribed angle. In this case, the cam tube 5 is rotatably supported by 
the camera body 1, and the retaining tube 6 as well as the ornamental ring 
2 are mounted to the camera body 1 in an axially slidably but rotatably 
fast manner. The internal structure for the adjustment of the focusing and 
aperture opening may be identical to that described in the previous 
embodiment or other conventional arrangements. 
FIG. 15 illustrates the functional structure of the third embodiment. The 
switches 15 and 16 are connected to a CPU 21 which in turn controls a 
first motor 22 for actuating a focusing mechanism 23 and a second motor 24 
for actuating an aperture opening selecting mechanism 25. The CPU 21 is 
programmed in such a manner as to adjust the focusing mechanism 23 
appropriately when either one of the switches 15 and 16 is closed. At the 
same time, the CPU 21 forces the aperture opening selecting mechanism 25 
into closing the aperture opening as required. Preferably, the CPU 21 also 
enables the strobe light 12 when either one of the macro modes is 
selected. To fully automate the operation of the camera, a range sensor 20 
may be provided in the camera so that the adjustment of the focusing 
mechanism 23 may be accomplished simply by aiming the camera to the object 
to be photographed. 
Thus, according to the present invention, because a number of settings 
which make the camera suitable for close range photographing can be 
achieved with a single operation, even an inexperienced person can take a 
satisfactory picture of an object at a close range. In particular, by 
reducing the aperture opening when a macro mode is selected, the focal 
depth can be increased, and a clear picture of the close range object can 
be taken without regard to the condition under which the object is placed 
in relation with the surrounding objects. By enabling the strobe light or 
a flash bulb when a macro mode is selected, it is possible to avoid the 
possibility of any insufficient photographic exposure of the photographic 
film. 
This new possibility opens up new applications of a camera such as 
preparation of data for various purposes as opposed to conventional 
inexpensive cameras which are considered to be useful for taking snapshot 
pictures. For instance, cameras according to the present invention would 
be useful in medical applications (by taking pictures of affected organs 
before and after treatment), educational applications (by taking pictures 
of small creatures, insects, plants and minerals), civil engineering and 
construction works (taking pictures of various parts of structures and 
furnishings of interest), forensic applications, and house keeping 
applications (by taking pictures of cooked dishes, flower arrangements, 
hand-crafted objects, knitting, lace and sewing works), among other 
possibilities. Cameras according to the present invention are so easy and 
simple to use that such pictures can be taken without any professional 
help. 
Although the present invention has been described in terms of preferred 
embodiments thereof, it is obvious to a person skilled in the art that 
various alterations and modifications are possible without departing from 
the scope of the present invention which is set forth in the appended 
claims.