The Optical Magic Lantern Journal (June 1889)

Theo Optical Magic Lantern Journal and Photographio Enlarger. easel, uncap the lens and give it the proper exposure, which will vary from a few seconds to several minutes, according to the strength of the negative and light. If youare uncertain about the necessary time of exposure, pin a small piece of bromide paper on the easel to cover the most important part ofthe picture,exposeand develop. This trial exposure ought to show you just how long to expose the full sheet of bromide paper, and will prevent waste. The best exposure is not less than twenty or thirty seconds. The lens can be stopped down to decrease the light if necessary. By giving the proper time of exposure, you can make a strong print from a comparatively weak negative, and vie versa. In fact, we have more latitude with the bromide process than any other photographic process known. To make a vignette picture, the operator, standing at the left and half facing easel, should screen MoDe OF VIGNETTING. the lens with a piece of card board about 16 by 20 inches. A hole of the proper shape for the vignette iscut inthecentre. Having uncapped the lens, the vignetter should be moved back and forth from the lens to the easel. Continue this movement through the entire exposure. Additional time can be given on any part of the image that may need it, by cutting a smaller hole in the same size card board and proceeding about the same as when vignetting. On landscapes extra time may be given on the sky by shading the balance of image with a piece of card board of the proper shape; the most beautiful sky effects can be produced in this way. !the water and flow with the developer. |image should develop up strong, clear, and 5 The developer may be as follows :— No. 1. Oxalate of potash ı pound. Acetic acid 3 drachms. Water des ... 48 ounces. No. 2. Proto-sulphate of iron ... B 1 pound. Water eh ... 32 ounces. No. 3. Bromide potassium I ounce. Water ı quart. To develop, take of No. ı, six ounces; of No. 2, I ounce ; and of No. 3, half a drachm. Care should be used in measuring No. 3, as an excess of bromide will produce too great a contrast, and too little will have a tendency to flatness. If you prefer to have your picture come up slowly, this developer can bediluted with one-third the amount of water. Ina suitable tray, soak the exposed print in'clean water until limp. Then pour oft The brilliant. When the shadows are sufliciently black, pour off the developer, and flow the print with the clearing solution, which consists of acetic acid, I drachm ; water, 32 ounces. Use a sufficient quantity to flow over the print. Allow itto act for one minute. Then pour it off and apply a fresh portion. Repeat the operation a third time. | Then rinse in water and immerse for about ten minutes in the fixing bath—hypo-sulphite of soda, 3 ounces;; water, I6 ounces. After fixing, wash thoroughly for about two hours, and hang the print upto dry. A good method to force an obstinate spot on the print when developing, is to dip the fingers into the developer and slightly rub the obstinate part. Care should be used not to overdoit, and to have no other chemicals on the fingers, as it would leave a stain. Beautiful results on bromide paper are also obtainable with the hydroquinone developer. To mount, wet the print, brush over the back with a thin starch paste. Lay the print on the mount.and rub down with a soft damp sponge. Some operators would like to see the print retain the gloss, as when in the water; this can be done by squeeezing the print face down ona polished piece of hard rubber. When dry the print will peel off with a fine glossy surface. A higher polished surface can be attained by enamelling with plain collodion on a plate glass. Amateur Society of New York.