YS2003 said:
I heard UV Filter is recommended on lens for SLR cameras to protect it from UV rays. Do you use them on your lens?
How do you select which filter is good for each lens (ie. not to degrade the image quality)? I have Tamron AF28-75mm F/2.8, Canon 70-200mm f/2.8L usm, 50mm f/1.4, 100mm f/2.8.
It's not about UV rays. A UV filter will help you with the colour of your shots: by filtering out UV light, you lose a blue "haze" that can otherwise be apparent on film (not sure about digital shots.) However, that's not the main reason why all of my lenses have a UV filter on the front.
I've spent a lot of money on my glass (the 100-400, in particular, is not a cheap lens.) Compared to the $2300 (Australian) it cost me, $90 for a high quality UV filter is nothing. It protects the front element from dust, scratching, and similar - if the UV filter gets damaged, I just take it off and put a new one on. If the front element gets damaged, though, it's not so cheap. Consider it a cheap form of insurance. The UV light won't do the system any significant damage; it's just that UV filters are probably the cheapest filter out there that won't alter the quality of the light coming in.
Does doing this drop the quality of your shots? Probably, but the difference - at least to my eye - is so slight, it's not something I consider worth arguing about.