I currently have t1i w/ the outdated canon 17-85 is usm. while the optical quality is not the best, it performs very well for my needs as a walk around lens. The only 2 things I want to do that I havent been able to do with this lens were taking photos indoors/dark at night, when the high ISO is still just isn't enough and being able to make macro shots. The minimal focusing distance is just too poor for macro, even at 85mm and the fact that it's a zoom kinda kills all the sharpness. Initially to solve my problem, I started looking at the 50mm lens but quickly figured out that on 1.6 crop they wont work as a good indoor. Then I scaled back to 28-30mm primes like the sigma 30mm 1.4 and canon 28mm 1.8. I've read a lot of good (and bad) things about either one but even 28mm just wasn't cutting it for smaller indoor rooms. So, then I started looking at lens like sigma 20mm 1.8 but couldn't find much information about it to make a decision. And then, looking at the over 500-dollar price of the thing, I seriously started considering other zoom's as even though more expensive, they seemed to get good reviews (especially f/2.8 ones) Though I really like the looks of it... So here I am, unable to make up my mind. With a starting budget of about $600 (or more if I decide to trade in my 17-85), what lens should I be looking at? Main considerations: 1. The wider the better(or is it on APS-C), where I shoot indoors there is pretty significant lack of space. Though some people say that using full-frame lens on 1.6 crop might still have significant degree of distortion, especially when photographing people indoors. 2. f stops is a requirement because that's one of the reasons I am shopping for a fast prime. 3. Though the lens' ability to take macro shots is not as much of the req as indoor use, I would really like for it to be able to make shots that look sharp when looking at the pic 1:1 or cropping it. 4. As someone else recommended, maybe I should just forget about all this and trade in my current lens, adding some cash on top to pick up some sort of zoom? f/2.8's like the Canon EF 24-70mm f/2.8L USM is just waaaay out of my price range. Any thoughts anyone?