Improvements in View Finders.
Year: 1898

page_text: Date of Application, 9th July, 1898
Improvements in View Finders.
1, JULES RICHARD, of 8, Impasse Fessart, Paris, in the Republic of France,
Manufacturer of Instruments of Precision, do hereby declare the nature of this
invention to be as follows;-
-
The present invention has for its object an improved construction of view finder
intended to be employed more particularly as a photographic view-finder.
My improved construction of view finder which is particularly characterised
by the special arrangement of its optical combination and by the regulation of its
eye-glass, gives a clear image, without haziness, and is capable of being focussed
for all sights.
The arrangement of my view finder permits of obtaining to a reduced scale, the
image of all the space embraced by the object glass of the photographic apparatus,
in such manner that the operator can thus clearly see all the points which will
be thrown on the photographic plate.
Further my view finder comprises cross hairs or lines arranged in such manner
that they appear quite clearly in the centre of the image and thus enable the latter
to be accurately centred.
My construction of view finder further possesses the advantage of giving a
very clear and sharp image, even of badly lighted parts.
In order that my invention may be clearly understood and readily carried into
effect I will describe the same by the aid of the accompanying drawings which
represent one mode in which I carry my invention into effect and in which Fig. 1
is a front view of the view finder. Fig. 2 is a plan, Fig. 3 is a side view and
Fig. 4 is a longitudinal section. Fig. 5 represents separately a frame which
arrange behind the second lens to limit the field.
In all the figures, like parts are indicated by similar letters of reference.
My construction of view finder, the external form of which may be, that of other
view finders, comprises at its front part two double-convex or plano-convex lenses a b
of short focus.
The lens has on its face opposite to the lens a two cross lines or hairs.
This lens is placed so that the cross lines or hairs are in the plane on which the
image given by the object glass a is formed; it has further for its object the cor-
rection of the aberrations of sphericity, the achromatic faults, and to send the rays
in the same direction parallel to the axis, so that the image may appear fixed by
the lens b, as it would be by a ground glass screen, but with this advantage that
there is no absorption of light. It is only necessary to view it with a magnifying
glass giving a convenient enlargement.
The luminous rays after having traversed the two lenses ab are reflected in a
perpendicular direction, and the image thus reflected, as also the cross hairs or
lines, are seen very clearly, with the desired enlargement, by means of a simple
or compound eyeglass.

page_text: This eye glass which is in effect a magnifying glass, may consist simply of
a double convex or plano-convex lens c.
In order that the apparatus may be adaptable to all sights, near or far sights,
the eye glass is regulable and for this purpose, it is mounted either by screw thread
or by slide upon the body of the view finder.
The luminous rays will be reflected in a perpendicular direction, preferably
by means of my arrangement of correcting prism.
In these conditions, the luminous rays, after having traversed the lenses a b
encounter the faces of the prism d arranged in such manner that there is pro-
duced a double reflection of the luminous rays, which entirely corrects the image.
This prism has one face parallel to the lens b, another face perpendicular to it
and consequently parallel to the eye-glass c, and two other faces inclined at 45°
to the preceding and cutting each other along their long side.
My improved construction of view finder therefore enables an operator to see
a very clear and absolutely exact image of the subject which he desires to take,
whatever may be the light and, in the case of moving objects, the image, which
he sees, moves in the same direction as the object itself, the placing on plates of
objects in motion is thus rendered much easier.
I would have it understood that I may employ any convenient arrangement to
reflect the luminous rays in a perpendicular direction and when it is sufficient for
the view finder to give a straight non corrected image I may replace the correcting
prism simply by a reflector at 45°.
My construction of view finder differs essentially from existing clear view
finders particularly by the position of the image of the object seen.
In certain types, the image given by the object lens is formed on a third lens upon
which the eye sees it; as this lens receives directly, in certain cases, the sun's rays,
it produces reverberations, haziness and a lighting of the image which considerably
reduce its brilliancy. It is further necessary by reason of the position itself of
this image, to place the view finder at the minimum distance of distinct vision.
If, in order to avoid the effect of reverberations, the eye is brought nearer, the
image is no longer in focus and only confused contours are seen; to remedy
this, there is no other resource than to protect oneself as far as possible against
the arrival of solar rays by forming a screen with the hand or with a small
shutter.
In my construction of view finder, on the contrary, the image given by the
object lens is formed at the interior of the view finder, as I have above described,
a little in advance of a reflecting instrument, in the plane of cross hairs or lines
and the third lens acts only as a magnifying glass enabling the image to be seen
with very great clearness.
In viewing therefore this image, with the eye glass or lens serving as a magnify-
ing glass, the field embraced by the first lens is seen, as this field may be much
larger than that embraced by the photographic object glass, I limit this field by
a frame arranged on the lens at the same place as the cross hairs or lines, either
by a deposit of black varnish or a metallic frame, or by roughing or grinding
the lens. For this purpose it is necessary to focus with this eye glass, according
to the sight of the observer.
In fact, in lieu of seeing directly the real image furnished by the object glass,
it is seen by the intermediary of a reflecting agent whose action is known.
From this it is seen that the real image produced in the interior of the view
finder cannot receive the direct action of the surrounding light and that in no
case can its brightness be lessened by the position of the observer.
It may likewise be noticed that the eye glass or lens being simply a magnifying
lens there is every advantage in bringing the eye as close as possible to it, which
in many cases, is useful when this arrangement is used as a view finder adapted
to a hand photographic apparatus.
In addition, when the cross hairs or lines are placed in the plane in which the
image is formed, the result is, that if the operator moves his head, he will not see

page_text: any relative displacement of the cross hairs or lines with respect to the object
seen, as is produced in certain existing view finders.
In a general manner, my construction of view finder permits of obtaining the
following results:-
-
1. The exact field of the image contained on the photographic plate.
2. The image slightly reduced in order to be embraced with a rapid glance of
the eye.
3. The clear image of cross hairs or lines dividing the photograph in order not
only to enable this image to be centred but to ascertain the horizontality of the
apparatus by the vertical lines given by the movements or by the line of horizon.
4. The image entirely corrected in order to see the inscriptions at the place and
to be able to follow a carriage or other thing in rapid movement.
5. The possibility of seeing even in badly lighted places and that this luminosity
is not a fault for the too great light of sunshine.
6. The facility of bringing the photographic apparatus as near as possible to the
eye, that is to say to the height of sight, and to remove it therefrom without the
picture ceasing to be clear.
7. The clear image of all objects seen situated at all distances.
8. The immovable image of the cross hairs or lines and of the object seen even
when moving the head, so as not to be obliged to centre the eye in the eye glass.
9. An easy adjustment enabling all sights, either long or short sight, to see
clearly the image as well as the cross hairs or lines and to keep this position.
10. The same view finder enabling a landscape to be placed lengthwise or
breadthwise, according to the position of the apparatus, and to view on the side
without inconveniencing the persons whom it is desired to take.
11. A sufficiently small size so as to occupy only the space of the ordinary view
finder even the smallest.
12. A distortion sufficiently corrected so that the lines given by monuments do
not mislead the operator concerning the inclination of the apparatus.
My construction of view finder presents in addition the advantage of being
strong, of being easily repaired and its cost price moderate.
I reserve the right to apply also my arrangement without the reflection agent,
when it is desired to look in the direction of the object seen.
It is well understood that my improved construction of view finder may be
varied in shape and dimensions and I reserve the right to modify the accessory
arrangements according to the different applications.
Datad 1 0+1 dov of 1900
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.
Improvements in View Finders.
I, JULES RICHARD, of 8, Impasse Fessart, Paris, in the Republic of France,
Manufacturer of Instruments of Precision, do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement;
-
The present invention has for its object an improved construction of brilliant
view finder, intended to be employed more particularly as a photographic view
finder.
My improved construction of view finder, which is particularly characterised
by the special arrangement of its optical combination and by the regulation of its
eye-glass, gives a clear image, without haziness, and is capable of being focussed
for all sights.

page_text: The arrangement of my view finder permits of obtaining, to a reduced scale, the
image of all the space embraced by the object glass of the photographic apparatus,
in such manner that the operator can thus clearly see all the points which will
be thrown on the photographic plate.
Further my view finder comprises cross hairs or lines arranged in such manner
that they appear quite clearly in the centre of the image and thus enable the latter
to be accurately centred.
My construction of view finder further possesses the advantage of giving a
very clear and sharp image, even in badly lighted parts.
In order that my invention may be clearly understood and readily carried into effect
I will describe the same by the aid of the drawings accompanying my Provisional
Specification which represent one mode in which I carry my invention into effect
and in which Fig. 1 is a front view of the view finder. Fig. 2 is a plan, Fig. 3
is a side view and Fig. 4 is a longitudinal section. Fig. 5 represents separately
a frame which I arrange behind the second lens to limit the field.
In all the figures like parts are indicated by similar letters of reference.
My construction of view finder, the external form of which may be, that of other
view finders, comprises at its front part two double convex or plano-convex lenses a b
of short focus.
The lens has on its face opposite to the lens a two cross lines or hairs.
This lens is placed so that the cross lines or hairs are in the plane on which the
image given by the object glass a is formed; it has further for its object the cor-
rection of the aberrations of sphericity, the achromatic faults, and to send the rays
in the same direction parallel to the axis, so that the image may appear fixed by
the lens b, as it would be by a ground glass screen, but with this advantage that
there is no absorption of light. It is only necessary to view it with a magnifying
glass giving a convenient enlargement.
The luminous rays after having traversed the two lenses a bare reflected in a
perpendicular direction, and the image thus reflected, as also the cross hairs or
lines, are seen very clearly, with the desired enlargement, by means of a simple
or compound eye glass.
This eye glass, which is in effect a magnifying glass, may consist simply of
a double-convex or plano-convex lens c.
In order that the apparatus may be adaptable to all sights, near or far sights,
the eye glass is regulable and for this purpose, it is mounted either by screw thread
or by slide upon the body of the view finder.
The luminous rays will be reflected in a perpendicular direction, preferably
by means of my arrangement of correcting prism, forming the subject of Letters
Patent granted to me and numbered 11640 of the year 1896.
In these conditions, the luminous rays, after having traversed the lenses a b
encounter the faces of the prism arranged in such manner that there is pro-
duced a double reflection of the luminous rays, which entirely corrects the image.
This prism has one face parallel to the lens b, another face perpendicular to it
and consequently parallel to the eye glass c, and two other faces inclined at 45°
to the preceding and cutting each other along their long side.
My improved construction of view finder therefore enables an operator to see
a very clear and absolutely exact image of the subject which he desires to take,
whatever may be the light and, in the case of moving objects, the image, which
he sees, moves in the same direction as the object itself; the placing on plates of
objects in motion is thus rendered much easier.
I would have it understood that I may employ any convenient arrangement to
reflect the luminous rays in a perpendicular direction and when it is sufficient for
the view-finder to give a straight non-corrected image I may replace the correcting
prism simply by a reflector at 45°.
My construction of view finder differs essentially from existing brilliant view
finders particularly by the position of the image of the object seen.
In certain types, the image given by the object lens is formed on a third lens upon

page_text: which the eye sees it; as this lens receives directly, in certain cases, the sun's rays,
it produces reverberations, haziness and a lighting of the image which considerably
reduce its brilliancy. It is further necessary by reason of the position itself of
this image, to place the view finder at the minimum distance of distinct vision.
If, in order to avoid the effect of reverberations, the eye is brought nearer, the
image is no longer in focus and only confused contours are seen; to remedy
this, there is no other resource than to protect oneself as far as possible against
the arrival of solar rays by forming a screen with the hand or with a small
shutter.
In my construction of view finder, on the contrary, the image given by the
object lens is formed at the interior of the view finder, as I have above described,
a little in advance of a reflecting instrument, in the plane, of cross hairs or lines
and the third lens acts only as a magnifying glass enabling the image to be seen
with very great clearness.
In viewing therefore this reduced image, with the eye glass or lens serving as a mag-
nifying glass,all the field embraced by the first lens is seen, as this field may be much
larger than that embraced by the photographic object glass, I limit this field by
a frame arranged on the lens at the same place as the cross hairs or lines, either
by a deposit of black varnish or a metallic frame, or by roughing or grinding
the lens. For this purpose it is necessary to focus this eye glass according
to the sight of the observer.
In fact, in lieu of seeing directly the real image furnished by the object glass,
it is seen by the intermediary of a reflecting agent whose action is known.
From this it is seen that the real image produced in the interior of the view
finder cannot receive the direct action of the surrounding light and that, in no
case can its brightness be lessened by the position of the observer.
It may likewise be noticed that the eye glass or lens being simply a magnifying
lens there is every advantage in bringing the eye as close as possible to it, which
in many cases, is useful when this arrangement is used as a view finder adapted
to a hand photographic apparatus.
In addition, when the cross hairs or lines are placed in the plane in which the
image is formed, the result is, that if the operator moves his head, he will not see
any relative displacement of the cross hairs or lines with respect to the object
seen, as is produced in certain existing view finders.
In a general manner, my construction of view finder permits of obtaining the
following results:-
1. The exact field of the image contained on the photographic plate.
2. The image slightly reduced in order to be embraced with a rapid glance of
the eye.
3. The clear image of cross hairs or lines dividing the photograph in order not
only to enable this image to be centred but to ascertain the horizontality of the
apparatus by the vertical lines given by the movements or by the line of the horizon.
4. The image entirely corrected in order to see the inscriptions at the place and
to be able to follow a carriage or other object in rapid movement.
3. The possibility of seeing even in badly lighted places and that this luminosity
is not a fault for the too great light of sunshine.
6. The facility of bringing the photographic apparatus as near as possible to the
eye, that is to say to the height of sight, and to remove it therefrom without the
picture ceasing to be clear.
7. The clear image of all objects seen situated at all distances.
8. The immovable image of the cross hairs or lines and of the object seen even
when moving the head, so as not to be obliged to centre the eye in the eye glass.
9. An easy adjustment enabling all sights, either long or short sight, to see
clearly the image as well as the cross hairs or lines and to keep this position.
10. The same view finder enabling a landscape to be placed lengthwise or
breadthwise, according to the position of the apparatus, and to view on the side
that is in a direction at right angles to that occupied by the operator without
inconveniencing or troubling the persons whom it is desired to photograph.

page_text: 11. A sufficiently small size so as to occupy only the space of the ordinary view
finder even the smallest.
12. A distortion sufficiently corrected so that the lines given by monuments do
not mislead the operator concerning the inclination of the apparatus.
My construction of view finder presents in addition the advantage of being
strong, of being easily repaired and of having a moderate cost price.
I reserve the right to apply also my arrangement without the reflection agent,
when it is desired to look in the direction of the object seen.
It is well understood that my improved construction of view finder may be
varied in shape and dimensions and I reserve the right to modify the accessory
arrangements according to the different applications.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. An improved construction of brilliant view finder comprising first at its
front part two double-convex or plano-convex lenses, the second lens, which
carries cross hairs or lines on its face opposite, to the first lens being so placed that
the cross hairs or lines are in the plane on which the image given by the first
lens is formed and secondly an adjustable eye glass, acting as a magnifying glass;
and a reflector at 45° directing the luminous rays, which have traversed the two
first lenses, into a perpendicular direction, or by preference a correcting prism
whose surfaces are so arranged that a double reflection of the luminous rays is
produced, which entirely corrects the image; the image of the object seen being
always formed in front of the correcting prism or of the mirror substantially as
herein shown and described.
2. In a view finder the combination of two short focus lenses in the front part
thereof arranged at a distance apart, cross hairs or lines on the front surface of
the rearward of such lenses, a correcting prism at the rear and at an angle of 45°
with such lenses and an adjustable eye glass above the upper end of such prism,
substantially as herein shown and described.
3. In a view finder the combination of two short focus lenses in the front part
thereof, arranged at a distance apart cross hairs or lines and a field limiting frame
on the front surface of the rearward of such lenses, a reflector or correcting prism
at the rear and at an angle of 45° with such lenses and an adjustable eye glass
above the upper end of the reflector or prism substantially as herein shown and
described.
4. In a view finder the combination in the front part thereof of a short' focus
object glass or lens, another short focus lens at a distance to the rear of such object
glass or lens and cross hairs or lines on the front of the rearward of such lenses,
substantially as herein shown and described.
T: 7th day
C 1900
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.