EF 20mm f2.8USM - filter

Anyome know if the Canon EF 20mm f2.8USM requires the ultra this type

UV filter (such as the Hoya Pro1 etc) or are the standrd thickness

filters OK without darkening the edges of the image (35mm full frame

rather than the 1.6crop format).

Thank you in advance

I used the EF 20/2.8 with negative and slide film for two years with 'thickish' filters: regular Hoya circular polarizer and (not at the same time) B+W graduated ND (screw-in). Never noticed a serious problem. But then again I almost never shot the lens wide open - usually at f/8-16 range.

I have this lens and have always used a "thin" filter on it. I really don't like (unintentional/unexpected) vignetting at all, and while standard thickness filters may or may not cause it, using the thin filter ensures it doesn't happen.

I often use this lense wide open at f2.8 on EOS1V and I have the {thin} filter all the time because I cant afford to have vignetted pictures.

 

It will be on the safe side to have a {thin} filter just in case although I have used {thick} filters and there wasnt any problems.

I have a Hoya polarizing thin filter for this lens, and I find it a pain to use. The biggest issue is the lack of anterior threads. The lens cap is therfore made of rubber, designed to grasp the lens on the outside without needing anterior threads. That lenscap slips off all the time, and of course you can't hold the camera and filter in a camera bag since the lens cap is pulled off by the grasp of the camera bag. I am amazed that I haven't lost that lens cap yet. Fortunately I don't often need a polarizer on such a wide lens, as the result is often poor balance of sky tones over the broad field of view. I question why you feel you need a UV filter at all. The benefit of a UV filter is not worth the effort, in my opinion. With the lens cap falling off all the time you will find yourself taking the filter on and off, kinda defeating the purpose of less risk to anterior lens elements. If you feel you need a filter, I would get a normal one with anterior threads so you can still use a normal lens cap. I would be a little surprised if Canon didn't design the lens for use with a single normal filter.

For 35mm film (EOS 3) I had to buy slim B+W filters for my 24mm f/3.5 TS-E. The focal length is longer and apperture is a bit smaller, but even this was enough to see vignetting on slides. With wider angle of view and apperture of your lens, I'd think there is even more need for slim filter.