Year: 1897

page_text: Date of Application, 17th Feb., 1897
Complete Specification Left, 17th Nov., 1897-Accepted, 22nd Jan., 1898
I, WILLIAM DANIEL RICHMOND, of 18, Sparsholt Road, in the Parish of Isling-
ton, in the County of Middlesex, Photographer, do hereby declare the nature of this
invention to be as follows:-
Hitherto mirror boxes have been made either (a) with the mirror behind the lens
and between it (the lens) and the sensitive plate; or (b) between the lens and the
object to be copied.
My invention as herein described unites both forms in one instrument with the
collateral advantages hereafter mentioned.
To make clear the understanding of these improvements let it be supposed that
the object to be copied when this mirror box is used be hung, or stands in a ver-
tical position. Then the mirror box may be represented by the half of a hollow
cube, or a figure nearly cubical, which has been cut through its diagonal ver-
tically. This half cube is attached to the camera front by one square (or nearly
square) face the other square (or nearly square) face then projecting away from
the camera front at right angles to it. At the plane of the diagonal the mirror
is placed and thus the rectangular surfaces of the half cube all occupy a vertical
position. The plane of the camera front and the plane of the mirror box that stands
vertically at right angles to it are provided each with an opening preferably
square. In either of these openings there can be inserted, and held, a loose piece
which carries a lens and in either of these positions the apparatus will give reversed
negatives which is what such apparatus is designed for. There are certain advan-
tages to be derived from each position. When the lens is used on the projecting
vertical plane it has the advantage of permitting the camera to be moved further
away from the copying board than when used on the camera front and is in a
better position for either enlarging purposes; for the employment of long focus
lenses; or for giving more room for the use of electric lamps. As previously
stated the lens can be used on the camera front behind the mirror in which posi-
tion it is more suitable for great reductions; for short focus lenses; and for includ-
ing great angle of views. When it is desirable to include the maximum angle of
view of which the mirror is capable the lens is put behind it and all obstruction
must be removed. To this end I make the part in front of the mirror to work
on hinges so that it can be turned out of the way. It may have been observed
that from the nature of the construction the top and bottom portions of the box
are of triangular form have the mirror at the hypothenuse. It follows therefore
that a portion projects beyond the mirror and cuts off a portion of the light which
would otherwise reach it, but I obviate this difficulty by dividing each triangular
piece into two parts and while I leave one attached to the main body of the box
I secure the other to the previously described movable piece and thus the mirror
is cleared of obstruction when such movable piece is turned on its hinges out of
the way.
By the method of construction just described a practical difference of about a

page_text: angles while that at F1 F1 is more suitable for working near same size and for
enlargements.
When it is required to include a wide angle of subject the front may be found
to be in the way and I therefore make it removable by hinging it at C so that it
can be turned out of the way as shown in Fig. 8. It will be seen that it carries
with it a portion of the top K. The underside is made similar so that really a
portion of top and of bottom is put out of the way at the same time. This removes
all obstruction when it is desirable to include the largest angle of which the appara-
tus is capable and which cannot be done in mirror boxes of the usual construction.
At the back of the apparatus is the place of the mirror EE which in this inven-
tion, is put in from the back instead of from the front as is the usual practise. The
back is shown in half view in Fig. 3. By opening the door L, which has a light
spring on the inside to keep the mirror properly pressed against its seat, the mirror
can be lowered into its recess and may then rest on adjusting screws as shown
at M M.
It will be seen on inspecting the drawings hereunto attached that the back AC
of the box is united to the side A B by means of the piece J so that the portion K
can be made removable as indicated at Fig. 8.
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:-
Firstly the making of mirror boxes for photographic cameras in such a manner
that in one instrument lenses can be used either before or behind the mirror in
the manner shown.
Secondly the manner of removing the front portion of the mirror box for the pur-
pose of taking wide angles of view.
Thirdly the manner of inserting the mirror into its place from the back; and
Fourthly the use of adjustable screws for the mirror to rest upon, all sub-
stantially as herein set forth and shown in the drawing attached hereunto.
As witness my hand this Seventeenth day of November in the year of our
Lord One thousand eight hundred and ninety-seven.
WILLIAM DANIEL KICHMOND,