Focal Length for indoors

I am looking to get a fast prime for indoors use ( dimly lit rooms and parties). The other option would be a 16/18 - 50 f2.8 zoom, but not keen on the weight.

What do you guys suggest?

Have you thought about the sigma 30mm f1.4? it's a corking fast lens and great for taking shots of people; (relatively) not too pricey either, especially if you can find one second hand.

Is it wide enough in smallish rooms for candid group photos? I keep thinking 35mm is not wide enough (on APS-C)

There is also a Sigma 20mm F1.8, i don't think you can go much wider and faster.

Mat

Have you got the 30 mm on a K5?

Can you comment on AF performance in dim light?

I am a big fan of primes but nonetheless suggest you get the DA12-24mm for this task. Because you just might need 12mm indoors. And the IQ is second to none in this range.

I already have the Sigma 10-20 f4-5.6, but it not adequate in low light.

It's going to be use for candid individual/small group portraits (in low light) and well as the occasional large group "souvenir" snap

I've always found the FA50/1.4 to be pretty good (also the FA35/2 is nice). To avoid flash it's necessary to push the ISO (on my K10D, the furthest I'm prepared to go is ISO800 and that's only if I'm desperate to avoid using flash).

I've got some examples if you're interested - PM me if you're interested because they're from a family party and I don't really want to publish widely.

EM

Since the only fast wide primes have poor edges (e.g. all the Sigmas) they are not suitable for group portraits. Also thin depth of field does not work since someone will be out of focus. I would never think of anything less than f/2.8; in fact f/4 to f/8 is much safer. So a zoom that is sharp at f/4 (as I recommended) is quite ideal.

However, for portraits anything wider than, say 16mm has too much geometric distortion. So I retract my recommendation and substitute the DA16-45. It's smaller and lighter than the similar DA* and has somewhat better IQ to boot. I'd try not to go wider than 24mm but it's there if you need it.

Not enough light? That's why the pros use flash. Tilt and swivel are essential. Just buy the Metz 58 and learn how to use it.

A fast prime (Sigma 30mm / Pentax 35mm) will be great for individual 'portraits' or shots where only one person is in focus (e.g. a person talking while others listen) but I agree with Robin, for wide angle group shots indoors you need something a bit wider and reasonable DOF which will need flash (unless you have a K5 perhaps :wink. Bounce the flash off the ceiling.

Geometric distortion is a shame, but in some rooms you have no choice if you want to get everything in shot - the 10-20 would be OK but you might want to avoid the wide end! The kit lens might be just wide enough actually. Experiment in your living room and see what works for you.

+1, I've got a Tamron 17-50 f/2.8 and find that the distortion at the wide end away from the centre of the frame precludes portrait use. I'd second the suggestions that the 16-45 or kit lens would be worth trying. The Sigma 30/1.4 is excellent for individual portraits, but not so good for groups due to edge performance and narrow DoF.

If you want a fast, wide, unobtrusive prime, I can recommend the Kiron-made Vivtar 24mm f/2 if you don't mind manual focussing. It's about as small, fast and wide as I've found. The DA limiteds are smaller and wider and other lenses of equivalent speed/focal length are equally fast but bigger.

Just let the light bounce from the ceiling and 9 of the 10 times it looks really okay and natural.

smc Pentax 12-24mm or sigma 10-20mm and a flash will be an ideal combo for indoor photos.

Not a prime, but in a restricted indoor space, a prime may not be the best tool for the job as it'll be too restrictive.

It's hard to imagine going without an FA 50 / 1.4 -- great for restaurants or other dimly lit environs.