APPARATUS FOR ANIMATED PHOTOGRAPHY
"It is within the memory of some of you that
it was in this room, rather more than three years ago, that animated photographs
were first seen on the screen in England, and it was my privilege to show
them. I had been at work on the subject for a very long time before that
data, and I had successfully taken pictures more than a year before; in
fact, the first fairly successful animated photograph of any historical
event, as far as I can find out, was the photographing by myself of the
Oxford and Cambridge Boat Race of 1895."
"Animated photography really had its origin
in the old zoetrope, in which a series of drawings were made upon a band
of paper, each representing a phase of some animated scene, which was then
put into a revolving drum with slits in it to enable you to see each picture
as it came round, the result being a very fair representation for animation."
"The first serious attempt, that I can trace,
of showing animated photographs was made by Professor Muybridge, and I believe
they were shown at a Photographic Convention of 1889; but from what I can
gather (I was not able to see them) I do not think they were purely photographs,
but I believe they were drawings made from photographs with the special
idea of illustrating the movements of a horse, etc. In Professor Muybridge's
work a series of cameras, and, therefore, a series of lenses, was employed,
and that introduces a very serious defect to which I will refer presently."
"The next name, and a name which I think
must always be remembered in connection with this subject, is that of Mr
Friese Green, who, I believe, made the first serious attempt at taking a
series of photographs on one continuous band; I think he took out his patent
in 1893. The next work that I know of is that of Anschutz. You may remember
that about eight years ago Anschutz brought out a an improved form of the
zoetrope, or wheel of life, in the shape of a machine about two feet across,
and a series of reproductions of photographs of a horse jumping, or similar
subjects, the exhibition lasting about a second."
"Then Marey, in France, made a machine about
two feet across, and a series of pictures; he used one band of sensitive
material, on the same principle as Friese Green, but he did not get the
pictures properly spaced; the films were drawn off a drum, and the slack
was taken up much in the same way as in the apparatus which I am going to
bring before you, but without the very important addition of a guide. M.
Demeny also made an apparatus in 1895 which had the same defect; he took
a series of pictures, but it was necessary to cut them up and fix them on
glass, or something of the kind, in order to get them correctly spaced."
"The Edison Kinetoscope, of course, you have
all seen ; and then - without referring to the show I gave here in January,
1896 - the Lumiere apparatus was introduced, with which very successful
exhibitions were given. The latest, and perhaps the biggest achievement,
is that of the Biograph and Mutoscope Syndicate, and its success affords
a very good proof that there is something in photography, and particularly
in animated photography; indeed, I think there can be no doubt that animated
photography is destined to revolutionise our art-science, both as regards
matters historical and scientific, in addition to giving us lifelike portraits."
"In the apparatus of Muybridge and Anchutz,
as I before state, a series of lenses was used for taking the pictures,
consequently the scenes depicted by this class of apparatus were limited
to one plane, otherwise parallax asserted itself in the most confusing manner,
causing near objects to rapidly alter their relative position in regard
to distant objects."
"A simple illustration of this is obtained
if the eyes are alternately closed when viewing objects on different planes;
for example, if the finger is held up say a foot in front of the eyes and
a distant object observed, the finger would appear alternately to the left
and right of such distant object, and as the change of pictures is necessarily
very rapid to ensure continuity of vision, when animated photographs are
shown the confusion before referred to is very pronounced, hence these early
efforts were confined to representations of near objects only, the background
being quite plain."
"In Friese Green's early apparatus he had
not a perfect system of spacing the pictures, and, as far as I remember,
the films were not perforated, and he depended upon clamping the film and
drawing forward a certain quantity for each view. When you remember the
enormous magnification which the pictures undergo, you can readily understand
that is a rather difficult thing to get exact registration by that means."
"The apparatus of Marey and Demeny does not
call for further notice, and you are familiar with the Edison Kinetoscope,
but I may say a word of two about my own instrument, the "Birtac,"
and the way in which I have worked. I made a "claw" movement early
in the nineties, but abandoned it in favour of the sprocket wheel, the teeth
of which engage in perforations along the edge of the film, the latter being
also supported by the drum of the wheel, by which means the risk of damaging
the film is reduced to a minimum."
As the film is wound off from one spool it is
rewound upon another, so that there is no inconvenience or risk from having
twenty feet of loose film twisting about. If there are no perforations,
or if the claw movement is used, it is rather difficult to feed the film
forward, particularly if it is of any length; in the system I invented,
however, the film is fed forward at a definite rate, it is pulled forward
by the sprocket wheel, and as the film is firmly held by the sprocket wheel
there is no risk of the slip belt or other device which actuates the take-up
spool pulling more film than is actually fed out, whereas in some of the
claw movement machines, the mechanism for actuating the take-up spool has
to be very delicately adjusted, otherwise there is risk of the film being
pulled beyond its position in relation to the claws, in which case they
would cease to engage in the holes and the pictures would be thrown out
of register. Another objection I have to the claw machine, is that as the
claws only engage one hole at a time there is more risk of the film being
damaged."
"The Biograph uses films without perforations,
each picture measuring 2 3/4 inches by 2 inches; the additional weight of
film and the fact that there are no perforations, introduces a number of
difficulties which the inventors have overcome successfully."
"Celluloid - the material that, unfortunately,
we are obliged to use, because there is no other suitable - celluloid and
gelatine, when they come together, do not always remain of the same length;
a piece of sensitised celluloid which is 100 feet long to-day, may be an
inch or two longer to-morrow, and as much shorter the day after. Now, if
you have no perforations to ensure continual adjustment you must allow in
some way for this variation, and in any machine that uses films without
perforations it is therefore necessary to have an adjusting arrangement
to shorten or lengthen the amount of film drawn forward at each stroke."
"One of the difficulties which have stood
in the way of the adoption of animated photography, by amateurs and professionals
alike, arise in the development of the negative films, but I have overcome
this difficulty and rendered the operations of development, fixing, and
washing of the greatest simplicity. The films are wound upon a wooden frame
furnished with wooden pegs between which the film passes, and it is then
quite easily developed, fixed and washed in tanks resembling the old-fashioned
wet-plate dipping bath, so that the film need not be handled at all."
"Another drawback is the cost of film, but
by using films of half the linear measurement as in the "Birtac"
the area is reduced to one quarter, and the cost proportionally reduced."
"It will be noticed that the perforations
in the films used by me for the "Birtac" are not round, but cushion
shaped, rectangular with circular corners, a shape which provides a large
flat surface on which the sprockets may engage, thus greatly reducing the
risk of tearing."
"This is the standard perforation, the film
being simply split down the centre, so that films for this machine are obtainable
anywhere. It occurred to me that by placing the perforations between the
pictures I should certainly be able to get larger pictures with the same
width of film, as by perforating at the side the margin of the film must
be sacrificed; on the other hand, if they were placed between the views
something must be sacrificed; on the other hand, if they were placed between
the movement as the sprocket wheel will not work satisfactorily if the holes
are a considerable distance apart, as in that case they would have to be."
"The continuous contact of the clawing arrangement
with the film, too, has a tendency to split off little bits of the gelatine
at the perforations, which are the weakest parts of the film, and one cannot
afford to do this in the middle of a picture, but when the holes are in
the margin, this is of no consequence."
"The 'Birtac' is designed for home use, and
is so constructed as to be available both for taking and showing the photographs
with the single alteration of removing the lens form one place and fixing
it in another. The illuminant for projection is the incandescent gas-light,
but as the pressure of house gas is not always sufficient for the purpose,
I have devised a simple apparatus by which the gas is pumped into a bellows
and then fed to the burner, the pressure being thus very considerably increased.
the mantles are rather liable to injury, but I am informed that strong mantles,
that will stand almost any amount of pressure, will shortly be placed on
the market."
NOTES FROM THE MEETING:
Mr Birt Acres, at the conclusion of his remarks, exhibited
and described his apparatus, the 'Birtac,' and afterwards exhibited a number
of animated photographs by means of the same instrument, his method of increasing
the pressure of the gas causing a marked improvement in the power of the
light.
A few questions were subsequently asked, to which
Mr Acres briefly replied. He recapitulated the advantages of perforating
the margin of the film, as compared with the alternative method of having
the perforations between the pictures.
He had been unable to find a better developer for
the negatives when pyro-soda, metol being recommended for developing the
positive transparencies. With the increased pressure of gas he could satisfactorily
illuminate a 5 feet disc; the films were 20 feet in length, contained 640
pictures each measuring an inch by 3/8 inch in size, and occupied about
a minute in exhibition.
He had carefully considered the possibility of using
acetylene as the illuminant for projection, but having regard to the present
condition of knowledge with regard to that gas he did not feel justified
in recommending its adoption for this purpose."
A vote of thanks was passed to Mr. Birt Acres.
Source: © The Photographic Journal,
March 30, 1899, pp.188-191
