PRINTING LANTERN PICTURES BY ARTIFICIAL LIGHT ON BROMIDE PLATES FROM VARIOUS SIZES.[1]
By A. PUMPHREY.
There can be no question that there is no plan that is so simple for producing transparencies as contact printing, but in this, as in other photographic matters, one method of work will not answer all needs. Reproduction in the camera, using daylight to illuminate the negative, enables the operator to reduce or enlarge in every direction, but the lantern is a winter instrument, and comes in for demand and use during the short days. When even the professional photographer has not enough light to get through his orders, how can the amateur get the needed daylight if photography be only the pursuit in spare time? Besides, there are days in our large towns when what daylight there is is so yellow from smoke or fog as to have little actinic power. These considerations and needs have led me to experiment and test what can be done with artificial light, and I think I have made the way clear for actual work without further experiment. I have not been able by any arrangement of reflected light to get power enough to print negatives of the ordinary density, and have only succeeded by causing the light to be equally dispersed over the negative by a lens as used in the optical lantern, but the arrangements required are somewhat different to that of the enlarging lantern.
The following is the plan by which I have succeeded best in the production of transparencies:
B is a lamp with a circular wick, which burns petroleum and gives a good body of light.
C is a frame for holding the negative, on the opposite side of which is a double convex lens facing the light.
D is the camera and lens.