Was yours rechipped?I just picked up a 15mm 1:2.8 D EX ser. 1015XXX.
Seems to be the version right before the latest DG(Sigma labels this as Digital with improved coatings).
I picked my copy up from a local fellow who said he bought it new six years ago and never used it once. :smile:
My version/copy seems to do quite well into the sun and has nice contrast/color as well as sharpness - even without the newest coatings.