TESTING INTERIORS FOR EXPOSURE.
When the exposure meter is being used to estimate for an interior picture, such as a church or a room in a house, the actino meter should be exposed in the worst lighted part of the subject, or, at any rate, the worst-lighted part which is to show detail, as, for example, in the lower left-hand corner in Fig. 167. A saving of time may be effected in using the meter by employing the stop which will cause the camera and meter exposure to be the same. If the whole tint or dark est tint is employed for this purpose, the stop would need to be exceedingly small— so small, in fact, as to neutralise any benefit which might arise from this method of working. In photographing badly illu minated interiors, etc., the fractional tints are a considerable aid. In the case of the " Standard " meter, the tints are on each side of the piece of paper, the quarter-tint side being distinguished by a white dot. Mr. Watkins has now upon the market a form of meter specially designed to indicate the exposures in indoor work ; all that is necessary is to count the number of seconds taken to darken the paper to the quarter tint, this indicating the correct exposure when an Ilford ordinary plate is used and stop f22. Or, preferably, the meter may be left exposing, and the lens—stopped down to f22—uncapped, and directly the paper has assumed the quarter tint the lens is again capped. The meter should
be placed in the shadows of the picture. Slower or more rapid plates, of course, require more or less exposure. It has been found by experiment that the first going on. From time to time the strip of bromide paper may be drawn out and ex amined for an instant, and as soon as it shows the first sign of darkening, the plate in the camera will have been sufficiently exposed. If a quarter-tint• is used, a stop necessitating four times the exposure. or f45, must be employed ; and for a whole tint one requiring sixteen times the ex posure. Such apertures, however, are not likely to be used for interior work if they can be avoided ; but the whole tint may be utilised in outdoor photography. A table is given with the meter which visible darkening of the paper is equal to one-sixteenth of the whole tint. If this is used, a stop requiring the exposure of that just named or f11.3 must be used. In addition to those before mentioned, there is now a new form of Watkins meter made in the shape of a watch with revolving scales on the dial. It is called the " Bee " meter, and is shown by Fig.