white balance

[mking1]

I plan on using my digital 8 camcorder underwater using video lights (2.8K), or available light with and without a “blue water color correction” filter. Considering these light source and filtering options, I am curious about the performance of the auto white balance. Does anyone have any recommendations or information concerning this subject?

Miles.

 

[Tony]

How does your auto white balance perform when you shoot indoors under incandescent light? Indoor light is usually somewhere in the 3000-3800 K range. If your camcorder can handle switching from shooting outdoors to indoors without a problem, this would be a good sign.

2800 K is going to be warmer than average indoor light, so it might be worth checking to seen if the instruction manual tells you what color temperature the auto setting handles. If it doesn't say, then if your camcorder has an "indoor" white balance setting, the manual might say what color temperature it sets for that, which is a probably a good proxy for what the auto can handle.

Tony

 

[mking1]

Tony:
You bring up a good point about how it functions in an indoor or outdoor lighting environment. And it seems to be okay. The manual doesn’t say anything about “white balance” and nothing on the SONY web site either.

My real concern is when on land the light quantity and color temperature remain generally constant whereas underwater the ambient light quantity and color temperature changes are more frequent as your depth increases or decreases, add correcting filter, remove correcting filter, turn on video lights and turn video lights off. The color temperature underwater is more dynamic than it is above the water. Consider the following scenario:
1. before dive on boat, turn power on, above water in full sun, no color corrector filter. assume camera’s circuits does some type of “auto white balance”.
2. submerge to 50 feet, ambient light = full sun less reds, color corrector filter on lens
(question: what does the “auto white balance” do now? I’m also assuming it does an “auto white balance” on each press of the rec button)
3. still at 50 feet, remove color corrector filter and use video lights. (Assuming another “auto white balance” with the press of the rec button)

Does this question make any sense? Hopefully this “auto white balance” circuitry is real smart and everything will be okay. Or I spent way too much money for something that isn’t going to give me acceptable results.

Miles.

 

[Tony]

Yes, you're right about the varying conditions u/w. Very challenging.

I think it depends to a large extent on your camcorder. I had a Sony TRV 900 before, and no problems. If you have a newer model, I would wager that it won't have a problem with changes per se.

One way to test on land it to stand near a window in a room without other source of outside light, shoot outdoors in bright sunlight and rapidly move the camera to point to an indoor light source, like a light bulb. Or have someone close the shade so that the primary light is indoor lighting. Or do the same thing in reverse, ie indoor to outdoor.

Without any additional filters, most camcorders now should handle this just fine. There may be a slight delay, but the transition should take place. Provided it does, then the issue is whether they color temperature it produces under your video lights is what you want.

Tony
www.silent-symphony.com

 

[mking1]

Excellent. I'll do that test after sunup.

Miles.