Filters are used to eliminate ultra-violet, excess red or blue etc that will affect our image. Some filters are for special effects.

As the use of filter will degrade the image quality, except for unavoidable adjustment or requiring special effect, it is not recommended.

Basically, coating of lens and film can eliminate ultra-violet. Since there are individual situation that it may not happen here may happen there, it is better to prove by test.

General use filters include:

UV (Ultra-Violet) is the basic optic glass which can eliminate UV.

1A, 1B (Skylight) are equivalent to 1/3 and 2/3 of 81A respectively. Same effect as 81A with lower effect.

81A, nick-named Cloudy to remind its use in daytime especially mid-day, is used to get rid of excess blue color.

82A, nicknamed Morning & Evening to remind its use, is used to get rid of excess red color in the morning and evening.

PL (Polarizing) is used to get rid of polarized light, e.g. reflection on water or shinny surface.

Soft filter is used to have soften image effect.

Besides UV, all filters will block light with different level. Except TTL metering, we have to refer to the instruction to compensate the exposure. According to our finding, TTL metering may not be accurate for some cases. It will be better to check with no filter first, then meter again with the filter. Compare the readings with the suggestion from instruction. If there is difference, then either use manual setting or exposure compensation to correct.