transmitted. Such filters do not begin and end
transmission at precise wavelengths.
absorption. Dichroic or interference filters pass certain
precise wavelengths and reflect all others.
their stability and long life, dichroic filters provide more
Handle these filters carefully and only the edges. When
not in use, gelatin filters should be stored in their original
package, or they can be stored in clean paper between
pages of a book. Gelatin filters should be kept flat and
stored in a dark, dry place. Continued stress on gelatin
filters can deform them permanently. When stored in
high-humidity areas, they can become cloudy.
or by clean, low-pressure air.
should be kept in protective boxes or containers and
should never be exposed to dampness or dirt. Never
wash glass-mounted filters with water. When water
glass-mounted filter, it causes it to swell and allow air
to enter between the gelatin and the glass. That causes a
the lens cleaner to touch the edges of the filter. Large
pieces of grit should be removed with a camel's hair
brush before attempting to clean the filter.
humidity, and time affect the stability of the dyes and
shorten the life of the filter.
You should know the ways in which filters are used for
exposing light-sensitive materials. Filters are an integral
link to high-quality products. This knowledge provides
you with an invaluable tool in filter application for all
the various stages of the photographic processes.
Basic Photography Course