MOONLIGHT EFFECTS Real moonlight views are possible in very favourable circumstances, but most of the so-called moonlight photographs are taken in daylight, the usual method employed being to take the photograph with the sun facing the lens, but not included in the view. A cloudy day should be chosen and the exposure made when the sun is just disappearing behind a cloud, or re-appearing therefrom. Should the sun be included it will appear as a reversed (black) spot and the plate will probably be fogged. A very brief exposure should be given (the plate must, in fact, be under-exposed) and the developer should be restrained with potassium bromide in order to give great density to the bright edges of the clouds and other high lights, without permitting detail to be over-pronounced in the shadows. The object is to emphasise the high lights, more particularly those in the sky and at other reflecting points.
The task of photographing a view illuminated by moonlight is not difficult if long enough exposure is given, but it is not easy to include the moon itself. The fastest of isochromatic plates, backed, should be used. As a rule, the best time is one or two evenings before the moon is full, as it then rises early enough to allow of the photographer making use of the diffused light of the after-glow to shorten the exposure, and if the moon is to be included the slight flattening of the disc will be hardly noticeable. In marine work, in harbours, or tidal rivers, where vessels are shown at a wharf or the water-line along a flat shore is included (such subjects and winter scenes make the best pictures), it is better, if possible, to make the exposure either at full or low tide, as then objects will not be blurred by a change of water level during exposure. An average subject, using f/8 and a rapid isochromatic plate, will need from ten to thirty minutes' exposure on a clear night. Do not under expose ; rather give double or even treble the exposures named.
W. S. Davis, of the United States, advocates two ways in which the moon may be included in the photograph without showing movement. One method is to wait until the moon is high enough to be out of the field of view included by the lens ; focus and expose for the fore ground as usual, remove the plate, then tilt the camera and raise the front until the moon comes where it is wanted in the composition, replace the plate and give a short exposure for the moon itself—from ten to thirty seconds will be ample with the lens at full aperture. The moon and the foreground are thus obtained upon one plate. For early moonrise effects, W. S. Davis exposes a separate plate on the moon, and guts it at the back of the foreground when printing. The first-named method is to be preferred, but care must be taken to locate the moon exactly where it is wanted. To do this properly take some gummed black paper and, before moving the camera for the second part of the exposure, decide upon the spot on the focusing screen it is to occupy, and attach a piece of gummed paper, in which a small hole has been made, so that when arranging for the exposure for the moon, the latter can be seen through the opening.
If wide-angle or medium-angle lenses are used, the image of the moon in the photograph will not appear so large, in proportion, as it does to the eye, and for this reason it is often advisable to use a longer focus lens for the moon than for the rest of the view ; otherwise the moon may be made to appear larger by having it a little out of focus.
Moonlight photographs are usually printed on sea-green or blue carbon, or bromide prints are made and then toned to those colours. Prints on P.O.P. may be stained by means of an aniline dye.