Drawar

The bigger the aperture the better. That's going to be your #1 factor. You can sometimes get away with a slower lens if it has good IS, but you'll still have to keep your shutter at or above 1/30 most of the time unless your performers are very still!

Aside from that, it really depends where you can be. If you don't have a lot of flexibility in your position, then you'll need a longer lens, or a zoom.

Here's some shots from a recent Jonathan Coulton Show.

This place had the worst lighting I've experienced. They had two red gel'd spots on the performers... and that was it the whole night. I hadn't brought a flash because I typically don't use them at shows, but I used my pop up flash a handful of times to get a colour other than red... argh.

That was shot primarily with a 70-200mm f2.8 IS (I shoot canon) I had my 50mm f1.4 along as well, but had better luck with some length. If I had an 85mm f1.2 that would've been the only thing I used.

Get the fastest glass you can afford. f2.8 is acceptable in well lit shows, but the faster the better. The higher ISO your body can handle the better as well.

Sounds like I need to get a second job! HA! Thank you for taking the time out to explain all of this. It's still Japanese to me but I'll get it. :)

Great advice from Ozone42 above.

Don't be scared to use macro lenses either. Usually coming with a default f2.8 aperture they are fast enough and allow enough light to get those gloomy shots.

Also expect some noise, you will be shooting with a high ISO (800+ sometimes) but that often adds to the atmosphere and the grittiness of the performance.

50mm f1.8 with a flash is great if you can get close to the stage - but I don't think performers like that in their face so shoot from oblique angles.

Look forward to seeing some of your work.

ISO 800 is a minimum for evening shows for me. I think I've shot that low once :) 1600 is the norm, with a lot of 3200 depending.

A bomb of a lens is the Nikon 70-200 2.8 VR as it is both great for low light, has a decent reach and has image stabelization. It will require quite a job though, so a possible alternative might be the 18-200VR which you can hand hold shots to 1/15th a second pretty easy. The problem then though is going to be shutter speed.

I owned a D70 at one time and they are great cameras but not all that great for low light, mainly because of noise and they use an older autofocus system.

Since one of the lenses I mentioned is $1800 and the other around $800 you may actually find a camera upgrade to the new D300 coming out as anothe roption since its low noise performance will far surpass your current D70. Its to go for around $1800 as well however you might be able to use a more affordable lens and shoot faster ISO's since it shold be good down to ISO 3200 and still yield a better result than your D70 at ISO 800.

The reason i mention this is because even though you can hand hold some of this down to 1/4 a second, the action on stage is going to require a shutter speed of 1/30 or 1/60th a second to prevent blur.

Acamera more capable of faster ISO's will allow faster shutter speeds and great DOF which will help yield sharper pictures with better image quality.

Hope you find this helpful, and don't give up! The gear you need is only a little hard work away!