Camera Work: A Photographic Quarterly (1908 (Heft 22))

brush, dipped in the reducer, is shaken to remove excess liquid, and then the
line or spot is brushed over or stippled. As soon as the reducer has acted
sufficiently, blot it off with a good blotter, being careful not to slide or pull
this, or the film will be torn at once. This process can be repeated till the
desired effect has been obtained ; naturally the plate is well washed after this.
The acid permanganate bath is best made up fresh every day or two, or
it is apt to spread a disagreeable deposit on the film during the reversal. To
facilitate this it is well to make up a very strong stock solution, by dissolv-
ing one-half ounce of permanganate of potash in sixteen ounces of hot
water. For use take two ounces of this stock solution to a quart of water
and add a quarter of an ounce of sulphuric acid.
The general color of a plate can sometimes be helped by dyeing a cover
glass to a pale tint of yellow. But this, as well as many of the after treat-
ments I have referred to before, are dangerous tricks in the hands of the
tyro. They are only intended for special purposes, or to save a plate that
can not be done again.
The varnishing of the plate is a factor of great importance, for the
varnish acts as a protection to the thin, delicate emulsion, and makes the
image brighter and more transparent. The gum damar varnish has many
disadvantages. It gets sticky with heat, and never seems to get absolutely
dry. A celluloid varnish, Zaponlac, has the advantage of more completely iso-
lating the film and of being insensitive to heat, but I have found this had a
tendency to lift off the emulsion on some plates. The chief point in favor of
the damar varnish is the facility with which it can be removed, and its quick
surface drying qualities. For lantern slides the celluloid varnish is best.
Concerning Artificial Lighting :—One of the most interesting sides
of Autochrome photography, and one that does not seem to have been con-
sidered at all, is color photography by artificial light. The use of flashlight
makes instantaneous color photography on Autochrome plates possible.
The color-screen supplied by Lumière gives a brilliant monochrome orange
color image by flashlight, very much the same coloring that some painters
employ in lamplight effects. In this way it can be used very advantageously
in combination with daylight. Popular and sentimentally realistic twilight
effects could no doubt be produced by giving an exposure in full daylight,
slightly less than normal, on a figure subject near a fireplace, for instance,
and just at the end of exposure setting off a flash that has been arranged
in the fireplace. The lens must be covered immediateiy, because the model
is sure to jump, and the room to be filled with smoke. I have tried nearly
all makes of flashlight powder, and find the Agfa powder most satisfactory,
giving least smoke and requiring least powder. The amount required is
about ten times that used on an ordinary plate. Aside from the use of the
flashlight for “ realistic firelight glows,” it can be used advantageously in
many ways to produce warm reflections on an arrangement, in connection
with daylight—this of course depending entirely on the judgment and taste
of the photographer. I have made a great many experiments with a view
to photographing in natural colors by flashlight and feel confident that much