Canon 100-400 Ghosting problems

[Charles Glatzer]

Steve (or anyone else with filters that compromise image quality).

I am doing a study of filters on image quality and would like examples of known filters that compromise image quality. I have one polarizing filter that does that and I found the two sides of the filter are not parallel. So if anyone has such filters and would like to donate them to my study (which I will put on my non-commercial web site), please contact me off-thread. I would like to see if any of these filters have characteristics people could quickly assess before buying. You can find other articles on my web site regarding image quality.

Roger,

I was recently told digital camera sensors do not fair well with fliters. The reasoning... lens elements are miniscus and filters flat, causing back-scattering of light.

Chas

[Jay Gould]

Interestingly, further to Chuck's comment that Canon does not officially recommend a UV filter which is also called a UV Protective Filter, the image from my 16-35 manual specifically contains a cautionary warning from Canon about the risk of not using a protective filter. If you do not use a protective filter and as a result you get dust and water inside the lens, have you voided your warranty?