How can i tell if I'm blowing a color channel if my histo on reads green?

SloYerRoll

I'm going out to do some concert shooting for the first time in a while.
I'm comfortable w/ all the settings of the camera and have a good idea of the terrible lighting I'm walking into.

My question is:
With all the gelled theater lighting. Is there a way I can tell if I'm clipping the blue or red channel on my shots since my D50 only references the green channel?

I'll be shooting higher ISO (800) since the D50 SUCKS at high ISO and hoping I can remove this in post. Using a 70-200 2.8 as primary glass. If I can get close, I'll switch to the 50mm.

Thanks for your time.

Cheers,
-Jon

ziggy53

Jon,

It looks like the Nikon D50 has Highlight point display (blinkies). I suggest you run a few tests and see if those are accurate enough for your purposes.

I do think you might still have to use ISO 1600, even at f2.8. Shoot in RAW and plan on post-processing and you should be able to squeeze a bit more performance as well as color balance.

Someone here, I forget who, suggested using Tungsten WB for theatrical lighting and I found that tip fairly useful.

SloYerRoll

Thanks Ziggy,

I normally leave my LCD set to highlight point display anyway. I assumed since my histo referenced only the green channel. The blinkies did the same. Or do the blinkes look at all three channels and make anything blown out blink?

I'll give Tungsten a try for the whole night. Thanks for the tip!

Cheers,
-Jon

ziggy53

SloYerRoll wrote:

... Or do the blinkes look at all three channels and make anything blown out blink?

...

I honestly don't know what anybody else's camera does.

It's pretty easy to check for yourself. Find something with fairly strong and pure colors in each of the three channels, RGB. You might even create something for yourself using a color printer.

Photograph the target using manual controls and try to get an accurate balance first for a benchmark.

Now vary the exposure, first in full stops more exposure. Purposely increase until you obviously overexpose, according to the "blinkies". Record on paper the exposures you used and the results.

Now back off the exposure by fractional amounts until the blinkies indicate you are no longer obviously over-exposed. Again record the exposures and results so you can compare in the next step.

Now take the series of images to a computer and use your favorite image processing software to review the results. Coordinate your notes with the empirical data from the image series and note how the camera blinkies compare to the software evaluation of the series.

In about 15 minutes you should have a much better understanding of what the blinkies mean on your camera.

SloYerRoll

Thanks for the process Ziggy.

You took the guesswork out of it so I'll know for a fact. I'll do this tonight!