Originally posted by Pretender I've worked with some fast primes (from other brands) f1.4 and f1.8 and I really liked the low light capabilities and the shallow DOF.
Was that film or digital? And if digital, was that with stabilization or not?
Quote: My question is if a choose to buy a f2.8 small tele zoom lens like the tamron 17-55mm or 28-75mm, will I significantly loose DOF capability and is the f2.8 a fast enough to use indoors without flash using ISO up to1600 or even 3200?
Small is a relative thing; those lenses are pretty darned big compared to typical primes in that range. But of course, small compared to, say, a 300/2.8.
Anyhow, here's why i wondered if your experience was film or digital. If film, f/2.8 probably seems rather slow, because you were probably not wanting to go beyond ISO 400. With digital, you can safely use ISO 1600 or 3200 with no more noise than ISO 400 film, so even with f/2.8, you'll be able to get faster shutter speeds than you used to get with f/1.4.
If your previous experience is with digital, then you may have been accustomed to usign ISO 1600 already, and f/2.8 is two stops slower than f/1.4. But that's just about the benefit you can expect from SR, so it kind of evens out. Except for moving subjects - where DOF would have been so shallow at f/1.4 that you'd have had little success anyhow - f/2.8 and ISO 1600-3200 is fine for "most" situations. And you may actually find yourself better off in those situations than you would have at f/1.4 with a faster shutter speed but shallower DOF.
Of course, when you specific *want* shallow DOF (these are rarely the same situations when you need fast shutter speeds), you won't be able to get as shallow. If you really like taking those kind of pictures, it might be worth picking up a cheap used manual focus prime just to get that capability when you want it.