need a good camera for volleyball action shots in a gym
which would be easiest to use, have a great flash? often low light in there
Angie: I'm going to do you a favor and tell you what I wish someone had told me when I first started shooting events: GET GOOD GLASS! The camera body is secondary to this in every scenario. My Nikon 300MM f/2.8 while heavier, (I use a monopod for long games.) makes any camera I choose twice as sensitive to light as my Nikon AF-S 300mm f/4 lens. So here is the rub, weight. If you simply CANNOT use a monopod, then get a 70-200mm f/2.8 and try to shoot AS CLOSE AS POSSIBLE. (DO NOT CROP more than you absolutely HAVE to! You are going to be at higher ISOs, and cropping will just make the noise & lack of saturation look worse!) The f/4 versions and slower lenses will simply force you to pump up your ISO to account for the loss of one f/stop of light or more, which will decrease the color and contrast quality of your photos as well as add more noise than the f/2.8 version does.
You really want to avoid letting your shutter speed drop below 1/1000 as a general rule. CAN you get good shots at slower shutter speeds? Sure! But better to not HAVE to because ISO value keeps getting too high!
BODY: I shoot the following in order of preference for low light/hi ISO capability:
* D300s - 12MP Least HI ISO capable (Don't like it above ISO 1600), Fast 8 FPS (Frames Per Second) with battery grip, excellent autofocus capability/speed in bright light, acceptable in poor light. DX-Crop gives the illusion of making my 600mm lens a 900mm lens!
*D700 - 12MP BEST HI ISO capability of my cameras (Like it up to 6400), Fast 8 FPS (Frames Per Second) with battery grip, excellent autofocus capability/speed in bright light, good in poor light. FX-sensor leaves my 70-200mm lens as a true 70-200mm.
*D800 - 32MP 2nd best HI ISO capability of my cameras (Like it up to 4000), SLOW 4 FPS (Frames Per Second) even with battery grip, excellent autofocus capability/speed in bright light, Excellent in poor light. FX-sensor leaves my 600mm lens as a true 600mm.
* D7100 - 24MP very good HI ISO capable (Like it up to 2500), decent 6 FPS (Frames Per Second), excellent autofocus capability/speed in bright light, excellent in poor light. DX-Crop gives the illusion of making my 70-200mm lens a 105-300mm lens.
D7100 considerations: Shoot 6 Frames in RAW & then the buffer fills. If you pace your shooting it's not an issue, but I can shoot RAW files with my D300s for as many shots as I've ever needed. Also the "1.3 Crop Mode" raises the FPS slightly to 7FPS, but again, after the 6th shot in RAW, it slows drastically. Shooting in plain JPEG, you can shoot many more like 24 consecutive shots or something, but I don't shoot in JPEG.)
FLASH: Just like the lenses, spend the money up-front to get the better flash. I love my SB-600 & SB-700 flashes, but when I need lots of light fired rapidly, my SB-910 is the flash I always use.
My suggestion for indoor volleyball based on my shooting indoor cheerleading experience:
Minimum - D300s (If flash is allowed) else D7100 | FAST 16 or 32GB SD cards (i.e. Lexar 600x) | 50mm f/1.8 (For Team/crowd shots) | Nikon AF-S 70-200mm f/2.8 VR/VRII lens | Extra camera batteries | SB-700 Speedlight | 8 minimum AA Eneloop rechargeable batteries (2 sets of 4 For your flash) | A decent camera strap (Don't even take the wrap off the Nikon strap! leave it in the box for resale and get a good Black Rapid "knock-off" strap instead. The Nikon strap "advertises" what you have to would-be thieves, and is a horrible strap to wear for any extended period of time!) Lastly, a CHEAP used backup body (D90, D300, D3000 that you'll keep your wider lens on, and switch to in emergency if your primary camera fails.)
RECOMMENDED - A good, used D3S/New D4 or new D800 | FAST 16 or 32GB SD/CF cards (i.e. Lexar 600x-1000x) | NIKON AF-S 300mm f/2.8 VR or non-VR lens | A Nikon TC-14e Teleconverter (Makes your 300mm f/2.8 a 420MM f/4 for when you can't be on the floor.) | Nikon 24-70mm f/2.8 (For Team/crowd shots) | A decent monopod ($30-$60) | Extra camera batteries | SB-910 Speedlight |16+ AA Eneloop rechargeable batteries | A GOOD camera strap (Don't even take the wrap off the Nikon strap! leave it in the box for resale and get an actual Black Rapid camera rapid-strap instead. The Nikon strap "advertises" what you have to would-be thieves, and is a horrible strap to wear for any extended period of time!) Lastly, a CHEAP used backup body (D300s, D7000 that you'll keep your wider lens on, and switch to in emergency if your primary camera fails.)
Yes, there are other options like the D3200 or D5200, but I'm betting that if you're serious about doing this, that you'll have traded-in either of those bodies for a higher-end/better performing one within the year, so why waste the money?
I hope that this helped you! And yes, I realize this is a decent amount of money, but better to pay once, and have what you need from day one, than to suffer, and either lose interest because you aren't getting the results you want, or end-up eventually re-spending to get what you should have bought in the first place...
To make your wallet feel better: I would shoot indoors with a Nikon AF-S 400mm f/2.8 VRII which costs more than all of the gear I've recommended for you in either scenario COMBINED just by itself! (See what's in store for you?) :-)