I have to both agree and disagree with you.
Cr4zYH3aD wrote in post #12667786
Some days ago I had to take pictures of a party (indoors). I did choose my Rebel XTi and the 50mm F/1.8. After all, I keep reading that low f/stop are magic in low light.
I agree you probably have heard that a lot. Unfortunately it is not entirely true. A wide aperture creates almost as many problems as it solves when it comes to low light photography. You can lose so much depth of field that it becomes almost impossible to nail focus, and you lose sharpness as well. I always strongly recommend that people with low-light issues attempt to solve them first with a good flash. Primes should be purchased primarily for their other benefits and secondarily for their low-light ability. Sell the 18-55 and save up a little more, then get a 430ex II, 580ex II, or an older generation version of those, as long as it has good ability to point the flash head nearly any direction you want.
1) 50mm is way too zoomed in for indoors shot - my fault, i guess - I was almost INTO the freaking walls.
I agree, it can be, depending on the size of the room. However, this is not a PRIME issue. This is a 50mm on crop = 80mm = too tight in some rooms issue. Heck, for certain kinds of shots the 17mm on your 17-50 could be too narrow.
2) even at F/1.8..It doesnt prevent shaky pictures. I'm kind of upset. I came to the conclusion that a low f/stop cannot replace a tripod or an IS lens..
I agree, it does not. However, that is because it is not really meant to. Shake is a function of focal length, shutter speed, and the steadiness of your hands. What a wider apertures primarily does in a low light situation is let you lower your ISO more. You should first be choosing your minimum acceptable shutter speed for the subject at hand a/o your focal length, no matter what ISO that results in. Then set your Aperture as wide as acceptable. Then finally set the lowest ISO you can without underexposing more than is appropriate for the subject. If you are limited to f/1.8 instead of f/2.8 then you can lower ISO 1 1/3rd stops more, and that can be huge, assuming that isn't too little DOF. I would actually recommend f/2 for a little more sharpness and DOF on the 50 f/1.8. 1/3rd stop ISO won't matter as much.
What comes into play here regarding IS vs non-IS is whether you are shooting moving subjects or not. IS will do nothing for you when shooting moving subjects indoors because your shutter speed needs to be fast enough for the subject, which will be probably 1/80 minimum, possibly much higher. What IS will do is allow you to lower your shutter speed on a static subject by a considerable margin, perhaps as low as 1/10 on a 50mm lens. This will then let you use a lower ISO or get away with a narrower aperture for more DOF.
3) When I bought my 7D, I was on a budget. So I took the Tamron 17-50 F2.8 (non VC). Well, I might sell my XTi to get the VC version, or the Sigma 15-50 F/2.8-4 OS HSM (290$). Of course, my 7D is far superior at high iso, so I might have just go with my 7D...
Sell the XTi, Kit lens, Tamron 2.8, and 50 f/1.8, which will all be redundant. Get a 430 EX II and either the Sigma 17-70 f/2.8-4 OS, the Sigma 17-50 f/2.8 OS, or the Tamron 17-50 VC.
Lesson learned... 1) no prime for indoors , 2) low f/stop is useless handheld, 3) a tripod would be too ackward indoors, and 3) I should always get a IS/VC/OS lens next time.
I disagree with 1. As I said earlier that is not a prime issue. That is 50mm being too narrow on a crop camera for the situation issue. If you had a 28mm prime you would have been fine.
I disagree with 2. It is not useless, you just need to understand what benefits it provides and how to use those benefits.
I disagree with 3 (1). Situations vary too much to state this unequivocally.
I disagree with 3 (2). For your next purchase it might be a good idea, but isn't a good idea for all circumstances, and is less of one once you have an IS lens.