(Note ** These are more advanced techniques and not recommended to alter unless you are aware of how they work )
How the camera is to deal with white when taking images
Record the picture lighter or darker than the image your are trying to take. Helpful when working in different light conditions like over bright or a dull day.
These are attached in front of the lens usually by screwing on and affect the image being taken
A colour glass is inserted into a holder in front of lens , the position (strength) and angle can be varied too
Having a UV or CPL also protects the lens behind against being dropped or scratched
Polarising increases colour of sky and water and can be varied in strength
Neutral Density Graduated – vary the sky to remove glare in white skies and darken areas