jimewall wrote in post #16492370
Definitely very usable at f/1.8, even better at f/2, by f/2.8 really excellent.
^^ Agree with this...In fact, someone was asking the same question over in the lens sample thread and my exact words were...IMAGE LINK: http://www.flickr.com/photos/coryshuler/8680027222/
"1.8 is decent, 2.0 is very good, 2.2 is sharp as you will ever need...at least on my copy. I used to only shoot it at 2.2, but have been less afraid of 2.0 recently."
If you really want to nit pick, I think this lens is FANTASTIC for the money. With this said I think it really shines in good light. I think it may lack a bit of "micro-contrast" that, at least for myself, may be perceived as sharpness. This is why when the light is a bit flat, I think the other 85's probably surpass the 1.8 in perceived IQ.
It is for these reasons and the fact that I LOVE 85mm that, if I had the money, I would go for one of the other two lenses. However, I don't trust the sigma enough with regards to AF, to buy used (not going to cough up the cash for new). Also, while some people say the sigma is great (and better than the canon's 1.8), I have not been overly "wow'd" by the lens sample thread on POTN or the flickr sample thread. Thus, I have never been compelled to take one for a test drive.
This shot was taken last winter but it was after this shot that I began to form my opinions about "micro-contrast". In the end, I think this lens may provide the most bang for your buck, taking into consideration nearly all lenses/focal lengths, you may ever find for a canon DSLR. I'm SO glad it is not only EF-s!!