Upload & Sell: Off
I use four types of filters for different reasons:
1) Circular polarizer ... very very useful in getting rid of reflections and haze, and not just from sunlight.
2) ND filters when trying to slow things down where I want/need a specific shutter/aperature combination and I'm already at the lowest ISO I can go. This happens with water falls quite often.
3) Graduated ND. Not something I use that often, but when I do, nothing else will do, including all the PP in the world ... or maybe more correctly said, 5 minutes fussing with a ND filter saves hours of post processing.
4) Clear glass filters ... for ease of cleaning ... NOT for protection. Some people think a clear glass filter protects the front element ... not really, and if it shatters, it actually is more likely to damage the front element. A lens hood protects the front element better than anything I know other than using caution. BUT, there are times when the clear glass filter is just so much easier to clean that it saves me time for no noticable degridation in image quality. A few examples:
Kids by the ocean splashing in waves .... ever get salt water that dried on your lens? Try and get it off that front element ... have fun spending hours cleaning it. With a filter, I can dunk the filter into a sink full of water ... cleans up in just a few minutes of drying. The trick to cleaning salt is copious amounts of water ... more than you want to put on your lens at any one time.
Equestrian events on a hot, dry dusty day ... tons of dust ... again, dunk in the sink when done. Only an issue for short lenses like a 17-55 when getting in close to the action ... obviously not an issue for the long lenses.
Spray foam fight -- need I say more?