Improvements in Enlarging Cameras.
Year: 1890

page_text: Date of Application, 7th Feb., 1890
Complete Specification Left, 7th Nov., 1890-Accepted, 13th Dec., 1890
PROVISIONAL SPECIFICATION.
Improvements in Enlarging Cameras.
I Walter Griffiths of Highgate Square Birmingham in the County of Warwick
Manufacturer do hereby declare the nature of this invention to be as follows:-
My invention has for its object improvements in enlarging cameras by means of
which I am enabled to enlarge to any extent upon either glass or paper from an
ordinary negative in a simple quick & effective manner by daylight or with an
ordinary lamp and without the necessity of working the camera in a dark room.
In carrying my invention into effect I form the enlarging camera with an oblong
body or box preferably square & open at the ends & formed of any such suitable
material as wood metal, stout mill-board or straw-board but I prefer to form it of
either of the two latter the ends being in that case strengthened with wood bands.
At the one end I fix the carrier in which the negative is placed the lens being placed
in the centre of the body & is so constructed & framed in a sliding partition that it
may be moved backwards & forwards within the body at the will of the operator.
At the other end I provide an end which telescopes within the body in which a dark
slide consisting of a frame with back & shutter & having a plain glass fixed therein
which is provided so that either sensitive paper or glass can be used as required &
which at the same time registers a position for correctly focussing the plate by the
use of a smaller piece of ground glass which is held against the clear glass in the
dark slide until the proper focus has been obtained by the telescope movement after
which the sensitive glass or paper is inserted in the place of the ground glass in which
position it will be understood it is exactly the same focus as the ground glass used
for the purpose of focussing.
The action of using my enlarging camera is as follows-
I insert the negative in the carrier with the film towards the lens. Draw the shutter
take out the back of the dark slide and adjust the lens partition & slide part until the
required focus is seen upon the glass in the dark slide. To move the lens partition
I remove the cap from negative end which then admits the hands after which I focus
accurately by placing the square of fine ground glass, against the large piece of clear
glass about midway between centre & edge in any direction: I then charge the slide
with the sensitive paper or plate in the dark room with its face next the glass, replace
the back & see that the shutter is closed afterwards inserting the slide in the camera
& exposing according to circumstances.
My improvements therefore, consist in the particular arrangement & construction of
the various parts as well as the use of the clear glass in the dark slide the whole
forming a compact portable & cheap enlarging camera easy of focus & capable of
being worked in the light & with an ordinary lamp.
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WALTER GRIFFITHS.
COMPLETE SPECIFICATION.
Improvements in Enlarging Cameras.
I WALTER GRIFFITHS of Highgate Square Birmingham in the County of Warwick
Manufacturer 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 :-
My invention has for its object improvements in enlarging cameras by means of
which I am enabled to enlarge to any extent upon either glass or paper from an

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ordinary negative in a simple quick and effective manner by daylight or with an
ordinary lamp and without the necessity of working the camera in a dark room.
In carrying my invention into effect I form the enlarging camera with an oblong
body or box open at the ends and formed of any such suitable material as wood,
metal, stout mill-board or straw board covered with American cloth or other similar
material but I prefer to form it of either of the two latter as being much cheaper and
lighter the ends in the latter cases being strengthened with wood or millboard ends.
At. the one end I fix the carrier in which the negative is placed the lens being
placed in the centre of the body & is so constructed and framed in a sliding partition
that it may be moved backwards and forwards within the body at the will of the
operator. At the other end I provide an end which telescopes within the body and
in which a dark slide consisting of a frame with back and shutter and having a plain
glass plate fixed therein which is provided so that either sensitive paper or glass can
be used as required & which at the same time registers a position for correctly
focussing the plate by the use of a smaller piece of ground glass which is held against
the clear glass in the dark slide until the proper focus has been obtained by the
telescopic movement after which the sensitive glass or paper is inserted in the place
of the ground glass, in which position it will be understood it is in exactly the same
focus as the ground glass used for the purpose of focussing.
My improvements therefore consist in the particular arrangement and construction
of the various parts as well as the use of the clear glass in the dark slide the whole
forming a compact portable and cheap enlarging camera easy of focus & capable of
being worked in the light & with an ordinary lamp..
In order that my invention may be clearly understood and more easily carried into
practice I have appended hereunto two sheets of drawings upon which 1 have fully
illustrated my invention.
Figure 1 is a general view of the exterior of one of niy enlarging cameras A most
suitable for obtaining enlargements of a usual or fixed size.
Figure 2 is a longitudinal vertical section through the centre of same.
Figure 3 is an elevation of the printing end of the camera shewn in Figure 1 with
the cap B removed.
Figure 4 is an elevation of the negative end of the camera shewn by Figure 1 with
the cap D removed.
Figure 5 is a longitudinal vertical section through one of my enlarging cameras
suitable for taking varied enlargements.
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Figure 6 is an elevation of the negative end of same with the cap removed.
Figure 7 is a sectional elevation of the lens frame of same.
Referring to Sheet 1 of the drawings. The body A of the camera is formed of any
suitable material such as millboard or strawboard with the end or ends strengthened
with wood, mill or strawboard bands such as a¹. At the one end of the camera E is
fixed in which the negative e¹ is placed and near the centre of the body A the lens F
is placed being mounted in the sliding carrier f¹ so that it may be moved backwards
or forwards within the body to any position, where it may be fixed by any arrange-
ment such as the thumb screw f2 or small screws f3 or may be so fitted as to remain
stationary without fixing. At the other end of the body A the dark slide H is
provided having the frame and shutters 2 and 3 with any suitable fastenings *.
For this dark slide the plain glass plate J is fixed so that either sensitive paper or
glass can be used as required and which at the same time registers a position for
correctly focussing the slide by the use of a smaller piece of ground glass which
would be held for focussing purposes against the clear glass J in the slide until the
proper focus has been obtained by the telescopic movement of the lens F. Referring
to Sheet 1 the action of using is as follows. The negative e' is placed in the carrier E
where it is secured by catches e being covered up by cap D the shutters H are opened
& the sensitive paper or glass inserted in the dark room after which the cap D is
removed and the negative exposed to the light according to circumstances.
Referring to Sheet 2 the action of focussing and using is as follows.
The
negative e is placed in the carrier with the film towards the lens F the shutters h¹

page_text: and 2 being removed and the metal shutter K withdrawn from the dark slide H.
The lens F is then adjusted from the negative end by placing the hands through the
openings e and e* and the dark slide being mounted in the telescopic frame M is
moved until the required focus is seen on the ground glass which is being then held
against the clear glass plate J and moved about midway between centre and edge in
any direction. I then charge the slide with the sensitive paper or plate in the dark
room with its face next the glass J and then replace the back close the shutter and
insert the dark slide H in the camera afterwards withdrawing the shutter K and
exposing according to circumstances.
may have two small metal ears attached to the sides of the lens frame F¹ sliding
in slots in the outer body A so as to allow of adjusting the lens f from the outside of
the body.
Having now particularly described & 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 :-
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1st. The improvements in enlarging cameras consisting of the body A negative
carrier E lens F and dark slide H combined substantially as and for the purpose herein
set forth and shewn.
2nd. The improvements in enlarging cameras consisting of the lens F mounted in
the sliding carrier f1 for sliding in the body A substantially as and for the purpose
herein set forth and shewn.
3rd. The improvements in enlarging cameras consisting of the plain glass plate J
for registering the focus for the paper or plate substantially as herein set forth.
4th. The improvements in enlarging cameras in which such cameras are formed
of mill straw or other similar board substantially as & for the purpose herein set
forth.
Dated 6th day of November 1890.
WALTER GRIFFITHS.