In fact, I used to have filters on all my lenses for 30 years,
BUT:
- I always purchased a filter from the same brand as the lens, e.g. SMC Pentax-A lens = SMC Pentax filter
Having said that, my principle was:
- Skylight gives you warmer, IMHO more pleasant colors on film. Therefore, all my Pentax lenses during the film age had a SMC-Pentax Skylight filter on
- During the digital age, automatic white balance makes the skylight filter obsolete, therefore I switched over to SMC Pentax UV filters.
However, recently I changed my mind, took off the expensive UV filters and started working with the lens-hood only.
BTW, I do not use protective LCD covers. I bougth the camera to work with it, not to sell it in pristine condition. So I'm not willing to subject to all the disadvantages of a LCD-protector just to avoid scratches.