- Y: Yellow
- YG: Yellowish green
- O: Orange
- R: Red
This is to strengthen or weaken colors.
LB filter can change the color temperature. For example, LB-A4 warming filter can make a bluish image looks white and LB-B12 cooling filter can make a yellowish photo look white.
Neutral Density Filter. Actually a grey filter to reduce light but not altering the color. It is numbered, such as ND2, ND4 and ND8. The ND2 filter allows 1/2 of the luminance to pass through, ND4 allows 1/4 and ND8 allows 1/8.
PL and CPL
Polarizer. It is has linear and circular versions. It will quarter the amount of light (i.e. EV-2).
Sky Light Filter. Pale pink in color, it can eliminate UV.
Eliminate UV to increase the image sharpness. But usually used as a protector.
Use small bubbles on the filter to diffract lights, so that a soft focus effect can be obtained. Because it diffracts light, it is better to use in situations that lights are not dim and from various directions, and shot using a large aperture.
Softers are usually numbered — the larger the number, the stronger the effect. Nikon system numbered it from 1 to 5.