I read on one of the forums where someone said they don't like to use UV filters cause they degrade the image with a layer of glass over the lens. While I'm not in the position to argue against that with lab conditions. I will say using 3 filters of glass over my lens did not seem to hurt IQ one bit.
Some background info...
I did not set out to do this test. Nor did I set out to shot the image with 3 filters on it. I was shooting some landscapes in the cemetery. I had a UV filter on, as I have on almost all my lenses. I also added a polarizer consisting of 2 glass filters. The polarizer was even dusty since I forgot to bring a blower with me. So 3 pieces of glass were in front of a 35mmA 645 lens. When it came time to shoot the gravestone I had forgot that I had the polarizer on it or would have removed it.
Let me apologize to those that are offended by religious symbols. I'm not religious myself. (Well I may be 'religious' about shooting in the cemetery!) So I did not pick the subject matter to do this test on. It caught my eye as an interesting grave stone with the weathering. And only after I saw the results and remembered the 3 filters did I decided to do a writeup on it. And to those of you who are devout in your beliefs...well you get a bonus with the filter test!
Pentax 645D, Pentax 645 35mmA lens. Top image has been cropped about 15-20% Hand held, no mirror lockup, no tripod. RAW image was processed as a 0,-1,+1 HDR with 3 images created from 1 RAW file.
The resulting TIFF is much sharper than these reduced JPEGs. But, you can still see the sharpness with 3 filters. Now it may be sharper with no filters. I never shot it wihtout at least 1. But the point here is 3 filters and it is still doable very nicely.
Last edited by slackercruster; 07-30-2012 at 03:57 PM.