[justchoi]

Black corners are found on those pictures taken with 20D+17-85 IS USM, mostly those with focal length 17mm. Is that normal??

[justchoi]

Black corners are also found with focal length 72mm and occasionally 85mm

[kernel]

唔會掛.......佢同20d一齊出架喎, 唔通canon自己玩自己??......are you sure?? pls post some sample here~

[vaworld]

May be ur filter is too thick, try to remove the filter b4 taking pics. If better, buy a "thinner" filter.

[justchoi]

Then, which brand of filter is better?

[Mike Chan]

My 'Canon Kiss Digital (in HK = 300D Blk Body)' use Kenko PRO1D protector(W). Ther is no such problem. I bought this filter in Japan. You can try TST if the shops there have such filter.