MONOCHROME VIEW METER.
A difficulty always strongly felt by the beginner is that of making allowance for the very different rendering of a coloured view when reproduced in monochrome. Often the chief charm of a landscape may consist of its harmonious and vivid colour ing, and since this is lost in the resulting negative, disappointment is apt to follow. Obviously, therefore, colour must be left out of the reckoning in selecting a suitable subject. A good way of ensuring this is to employ a monochrome view meter, which is made as follows:– Cut a piece of thin brass or other metal to the shape of Fig. 629, and cut also a piece of blue glass to the size of the inner clotted square.
Fix the glass in the frame by turning down the edges A, bend at right angles to the dotted line B, and bend also on the lines c and n to form a clip for the scale. The scale should be made of a strip of hard wood of the size shown in Fig. 630. and it should be attached to the glass and frame, and slide freely, but not too easily. The size of the opening E is immaterial, provided it is in exact proportion to the plate. To set the meter, place the camera so that some easily identified objects fall just within the focussing screen on each side, and, putting the end a (Fig. 630) against the cheek, move the frame to and fro slowly until the two objects fall just and composed in the finder ; this is also the case with the image on the focussing screen of the camera, providing it is in correct focus at the time. These are sel
dom used on stand cameras except when it is desired to photograph animals or moving objects ; in which case it is evi dently desirable to know the exact posi tion of the latter on the plate after the slide is drawn. They arc, however, prac tically indispensable for hand-camera work, unless the apparatus is of the reflex or twin-lens variety. The camera-obscura form, in which the image thrown by a small lens is received by an inclined mirror and thrown upward on a ground exactly within the square ; a mark is then placed across the strip H. When several lenses are to be used, their angle is found in precisely the same way and the scale is marked with a distinguishing letter, such as w for wide angle, N for narrow, and m for medium. This meter shows, without setting up the camera, whether the view is worth photographing, the amount that may be included, and the lens required. The blue glass reproduces the picture almost in monochrome, and gives a very fair idea of its appearance in a photograph.