Improvements in View-finders for Photographic and similar Purposes.
Year: 1895

page_text: Date of Application, 9th May, 1895
Complete Specification Left, 3rd Feb., 1896-Accepted, 7th Mar., 1896
PROVISIONAL SPECIFICATION.
Improvements in View-finders for Photographic and similar
Purposes.
I, GEORGE FREDERICK FRAAS, Optician, of 18 Portland Street Stepney,
England do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in view-finders for use in conjunction
with photographic cameras and for similar purposes. Its object is to provide a
This can be
bright image without the aid of a ground-glass or other screen.
accomplished in different ways.
1. By the combination of a lens or lenses with a prism in a suitable mount or
setting.
2. By the combination of a lens or lenses with a spherical reflector in a suitable
mount or setting.
On looking into the prism or spherical reflector at right angles to the axis of
the leus directed towards any object a distinct image may be clearly seen.
Dated this 9th day of May 1895.
Improvements in View-finders for Photographio and similar
Purposes.
I, GEORGE FREDERICK FHaas, Optician of 18 Portland Street, Stepney,
England, do hereby declare the nature of this invention and in what maunor the
same is to be performed, to be particularly described and ascertained m and by the
following statement :—
This invention relates to improvements in view finders for use in conjunction
with photographic cameras and for similar purposes. Its object is to provide a
bright image without the aid of a screen of ground glass or other material. This
can be accomplished in different ways:-
1. By the combination of a lens or lenses with a prism in a suitable mount or
setting.
2. By the combination of a lens or lenses with a spherical effector in a suitable
mount or setting.
On looking into the pusin or spherical reflector at light angles to the axis of the
leus directed towards any object a distinct image may be clearly seen.
A prism only may be used with or without any mount or setting. I do not biud
myself to any particular form of prism as the sides may be all plane or curved, or
combinations of planes and convex or concave curves. The hypotenuse of the
puism may be silvered or not as preferred.
Fig. 1. illustrates a very convenient form. A. is the prism, B. the lens, and
C. the mount or setting. The relative positions of the lons and prism can be easily
found by an ordinary optician or mechanic.

page_text: The curved surface of the prism is to magnify the image and to collect the rays
transmitted by the front leus, where one is used.
The most portable and convenient method of setting is a light metal box, but
any other material cau be used.
The lenses may be bi-convex, or plauc-convex, or "clossed"
prefei red.
convex 86
The spherical reflector form is composed as shewn in Fig. 2. A. 18 the spherical
reflector formed of a plano-convex lens cemented on to a silvered murio, B. is the
lens through which the image is viewed, C. is the lens by which the image is
formed. This may be dispensed with, but I consider a better result is obtained by
using one.
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. A view finder having a prism or prism and lens substantially as described and
illustrated in the accompanying diawings
2. In a view fuder for photographic purposes having a combination of prism and
leus or lenses as herein before set forth.
3. In a view finder the combination of a lens of lenses aud sphenical reflector
substantially as herein before set forth,
Dated this 3rd day of February 1896.
GEORGE FREDERICK FRAAS.