Shooting indoor Karate

tigerpaw

I have an upcoming karate tournament in
an old school gym. it has overhead hi pressure sodium lamps. I'm shooting with a nikon d90 with a selection of lenses. my question is.....should i preset white balance and keep it, or do i let the auto work. when do i set the iso to an upper level? or do i let auto work. there is a little ambient light high up and it filters down some. there are red and blue mats on the floor.

johng

The only time custom WB doesn't work is when lights are spread too far apart for overlapping fields of light (which will also happen more as you approach the walls). So, try a custom WB and take some test shots. When you take the custom WB shot - do it at a shutter speed of 1/60 - this will give you an 'average' temperature. Then take a burst of test shots at your normal shutter speed- look at them. If there's a problem you'll see it immediately as each shot will have a different color cast. If you're in that situation, put it in auto WB and shoot RAW. In any case, don't let the camera control your exposures - use manual exposures. You don't want metering thrown off by black vs. white gi or bright/dark backgrounds. Just keep in mind that if there are multiple rings, those by the walls will likely be darker than those away from the walls so you'll want to adjust your exposures when you switch between which ring you're shooting.

mercphoto

A shutter speed of 1/125 should also give you an "average" temperature as well. Sodium lamps are bound to be an issue as I *think* they cycle their color temperature with the cycling of the supply voltage. And if this is the case then you will always be rolling the dice with white balance at any shutter speeds other than 1/60 or 1/125. John has good points about shooting manual, shooting raw, etc.

Can you use flash?

Zerodog

I would set your custom WB with a grey card or an expo disc and run with it. Set it to ISO 3200 and try to not under expose at all. If you have to bring it back, that is where you will get noise like crazy. If you get the WB and exposure right, noise won't be as big of a problem at 3200.

I would also recommend JPEG so you can take full advantage of the in camera NR and one of the best features of a Nikon, Active D. But remember with JPEG your WB needs to be close. You won't have the wide range of adjustments of RAW.