MAKING LANTERN SLIDES.
There is no pleasanter part of the art photographic than the making of lantern slides. Permanent Bromide lantern slide plates are coated with an emulsion similar to that used on Bromide paper and are developed in exactly the same manner. Lantern slides can be made by contact printing from x 4 or smaller negatives, and from 4 x 5 negatives, except when it is necessary to retain everything shown clear up to the edges of the orig inal negative. From larger negatives the lantern slides are made by reduction, a process similar to that of enlarging except that the Bromide slide plate must be nearer the lens than the negative—the reverse of the enlarging process where the further from the lens the paper is, the greater the enlargement. By either the contact or enlarging process the operation of slide making is very simple. If the operator is provided with a develop ing and printing outfit, the only extras required for contact printing will be doz. Permanent Bromide Transparency Plates. doz. Cover Glasses with Masks.
Take a negative and fasten it in position over the paper mask by means of a bit of gummed paper, and lay the mask with the negative on the clean glass plate in the printing frame with the between the mask and the glass. Lay one of the plates coated side down, on the negative in the frame, fasten the back of frame and expose as directed in the following paragraph.
The exposure varies with the intensity of the negative, and the quality and intensity of the light, but may be approximately stated to be, using as thin a glass or transparent film negative as will make a good print, one quarter second by diffused daylight, or ten seconds at a distance of one foot from a number two kerosene burner. Very thin negatives should be printed
by weak yellow light, like that obtained from a kerosene lamp turned down a little below the normal intensity. In this way a strong, vigorous slide may be obtained from a negative that would otherwise be too thin and flat. Strong, intense negatives are best printed by daylight.
Take the plate out of the frame and lay it on one of the trays, and cover it with either of the developers recommended for bromide paper on page 135.
The image will appear in a few seconds. The development should be continued until the black parts begin to get opaque by transmitted light, or about one or two minutes, then the developer should be poured off and the plate flooded with clean, cold water. After rinsing it three or four times it should be put into another tray and covered with the Hypo-sulphite Soda, - - - - - 4 ozs.
Water, - - - - - ---- 16 ozs.
This should be allowed to act for five minutes, or until the plate is clear and free from milkiness. Then the plate should be soaked in four changes clean \later for twenty minutes and stood upon edge to dry, when it will be ready for mounting.
'When dry, lay the slide face down on one side of the prepared covers having the mask on it, so as to have it come between the glasses. Then moisten the gummed edges and fold them over the slide.
Eastman's prepared cover g-lasses have mats and gummed binders attached, and will be found a great convenience.