Yet another seeking advice thread. Hopefully someone has done something like this or has some input at least. I have been shooting for almost a year now. I current have in my arsenal an XTi, Tamron 17-50 f/2.8, Nifty Fifty (1.8), 70-200 f4L IS and a Wigma. My most used lens is the Tammy and I quite like the results I've seen from it since I bought it. My current biggest complaints are that ISO 1600 isn't that great looking (exposure being right makes a big difference, but still quite noisy - even 800 is pretty obvious). Also the ability to focus in lower light situations (like a sporadically lit bar for example). I tend to look for high contrast details I can use to my advantage, but even then its somewhat hit or miss. Recently I tried it in probably the darkest bar I've ever tried it in and I had to use manual focus (which meant not many keepers). To my eye, I didn't think it was really that dark that the AF wouldn't pick up anything at all. Soo.. here is a few ?'s for people that have been doing this for longer than I have: I've been thinking a 35L would be a nice fast lens that would be great for these types of situations. I was hoping that the fast aperture of the lens would allow for better focus in low light situations. Is this true? While considering the 35L, I noticed that a 50D is quite close in price. From all I have seen results at ISO 1600 on my XTI are a fairly close match (noise wise) to ISO 6400 on the 50D. So hey, 1600 should be easy peasy for the 50D and even 3200 looks good. One real question I'd like to know is - will the AF system on the xxD cameras seem like a significant improvement over the xxxD series cameras under low light? If I upgrade the body then it seems like I'd get more use of my existing lenses given that I can easily use a higher ISO and get less noise. That's a bit of a bust if the AF system can't focus under low light. There is a ton of other things that are better about the 50D than just the AF system, however this is my main point of debate. I do realize that the viewfinder would probably make Manual focus a bit easier.