Filters have long been a popular accessory for photographers and offer a number of different functions or effects. In both analogue and digital photography it is possible to recreate some of these in the darkroom or digital darkroom. However there has always been a benefit to getting it right in camera.
In black & white photography, colour filters in particular are useful as they can control how the colours in a scene are reproduced as greys. Normal black & white films are sensitive to all wavelengths of visible light although how they interpret the colours of that scene will not always match the way you see it. Colour filters therefore allow us to modify, at the point of capture, the way the film will respond to the different colours.
Each coloured filter produces a different effect on the scene.
A yellow filter has always been the “classic” first choice filter for black & white film photographers. It gives an excellent balance between photographic effect and ease of use making it a useful and versatile accessory.
Many photographers use a yellow filter to “bring out the clouds”. This works by darkening the blue sky, giving a greater visual separation between the darkened sky and the white clouds on the final print. A yellow filter will also give improved penetration of haze and fog.
Although a yellow filter darkens blues, it reproduces green, yellow, orange and red in lighter shades. This gives more differentiation between the different colours of foliage while flesh tones have a more natural look.
A typical yellow filter will have a filter factor of 2 (the manufacturer will supply the exact factor). Most cameras with TTL metering will correct automatically for the filter factor but check your particular model.
Unlike the subtler changes given by yellow and orange filters, a red filter can create bold and dramatic effects. Blue skies are now recorded as black on the print, resulting in an impending thunderstorm effect. Pictures of mixed material buildings gain drama and clarity. A red filter will also give marked penetration of haze and fog. When used with a film like [SFX] it can create an infrared style look.
When shooting flowers without a filter there’s often little tonal difference between the flowers and the foliage in the print. A red filter will, in almost every case, give a significant difference in tone, making the photograph more interesting and dramatic.
A typical red filter has a filter factor of 4 to 5 (the manufacturer will supply the exact factor with the filter). Most cameras with TTL metering will not be able to automatically correct for the filter factor. Owing to the dramatic effects given by a red filter it is recommended that shots are taken giving +1 to +2 stops of extra exposure.
Orange filters give stronger effects than yellow filters but are not as bold and dramatic as a red. It is therefore an ideal choice to span the effects given by both these filters.
Blue skies will be recorded in very dark tones on the print, giving bold contrast between the sky and clouds. An orange filter will also penetrate haze and fog. Most flowers will be recorded with a significant difference in tone from the surrounding foliage giving impact and effect.
A typical orange filter has a filter factor of 4 (the manufacturer will supply the exact factor with the filter). Most cameras with TTL metering will not be able to automatically correct for the filter factor. Due to the dramatic effects given by an orange filter it is recommended that shots are taken with +1 stop extra exposure
When photographing foliage in black and white, a green filter is used almost exclusively.
It lightens green foliage, which is particularly important with dark green leaves which can record very dark without a filter. It therefore gives a more natural, lighter feel to the photograph.
Although limited in application, it can be the perfect solution for many photographs. A typical green filter has a filter factor of 2 (the manufacturer will supply the exact factor with the filter) while most cameras with TTL metering will be able to correct automatically for the filter factor.
A blue filter is not often associated with black & white photography however, it can really add “mood” to a photograph by increasing the effect of haze or fog.
It also lightens blues and darkens yellows, oranges and reds which helps separation in scenes containing a mix of colours.
A typical blue filter has a filter factor of 2 (the manufacturer will supply the exact factor with the filter) while most cameras with TTL metering will be able to correct automatically for the filter factor.