Improvements in or connected with Photographic Cameras.
Year: 1899

page_text: Date of Application, 10th Oct., 1899 -Accepted, 11th Nov., 1899
COMPLETE SPECIFICATION.
Improvements in or connected with Photographic Cameras.
I, JERZY FLECK, of 80, Chmielna-Strasse, Warsaw, Poland, Inventor, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement:-
This invention relates to photographic cameras and has for its object to pro-
vide a focussing device which shall obviate the drawbacks of the focussing
devices employed at present in photographic cameras.
The chief reason why various focussing devices have not come into general
use and have not enabled the primitive focussing cloth to be dispensed with, con-
sists in the fact that, (1) the focussing produced by their means can only be
extremely imperfect because it is effected by using only one eye which, however
close it is pressed against the focussing eye-piece, is never able to entirely prevent
the entry of light from the rear, so that the image on the focussing plate can-
not have the requisite sharpness; and (2) in cases where a rear bellows or focuss-
ing bag is employed, the same must be turned round according as vertical or
horizontal pictures are to be taken.
.
The improved focussing device, by which the two drawbacks above mentioned
are obviated, is illustrated in the accompanying drawings which show the device
applied to a photographic camera.
Figure 1 is a side elevation of the camera with the improved focussing device
in vertical section:
Figure 2 is a portion of the view of the device shown in Figure 1, drawn to a
larger scale; and
Figure 3 is a rear elevation of the device.
"
The improved focussing device comprises two parts or focussing bags m
and n connected together by means of concentric rings k, and that are rotatably
fitted together. The part m which has preferably the form of a bellows is
attached at its front end to the back of the camera. The part is provided
at its rear end with a mask g which is shaped to fit the face and which is formed
with sight-holes directed towards the focussing plate mounted in the camera
frame 6. These sight-holes are. perferably fitted with eye-pieces o o. In this
manner the two advantages which are found to be incompatible with each other
in other apparatus, namely, the complete exclusion of light, and the capability of
using eye-pieces, are here both obtainable in one device.
For the purpose of enabling the focussing to be effected with still greater
sharpness, the part n is made of soft light-excluding fabric.
If it is desired to view more fully the outer portions or edges of the image
on the focussing plate or screen, it is merely necessary to remove the eye-
pieces oo, together with the mask q, resting normally in a fork support (not
shown in the figure), out of the said support and to move the same around the
entire contour of the image within the limits of the ring .
The forked support is mounted on the upright e in which also the outer ring k
is fixed. The upright can be made to slide for the purpose of adjustment in

page_text: guides fixed to the camera frame and when the correct distance from the focussing
plate has been found, the upright c is clamped in the said guides by means of a
spring or pin.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
In connection with photographic cameras, a focussing device for use in taking
horizontal and upright pictures comprising two parts or bags" such as m and n
connected together in a rotary manner by means of concentric.rings such as k₁
and k, of which the rear bag (viz. that one which is farthest from the apparatus)
is provided at its end with a mask for the face such as q fitted with two eye-
pieces.
Dobal 4bia 1041 Ja of October 1900
J. C. MEWBURN & ELLIS,
55 and 56, Chancery Lane, London,
Chartered Patent Agents,