PDA

View Full Version : White Balancing Basics



The Publisher
08-10-2007, 01:06 AM
White balancing seems to have lots of confusing opinions bandied about, so I wanted to ad some tips on the concept of white balancing for video and that should give you a baseline to start from and establish your own techniques from there. Feel free to add your techniques, what has and hasn't worked for you.

The easiest way to white balance is to use a pre-made white balancing slate. Amphibico happens to make a fairly slick one show below.

http://www.amphibico.com/amphibico/images/image/1.1000182.ACWB0711blSM.jpg

You'll notice that the slate is not really white, but a bluish green tint. This more or less tells your videocam to warm things up a tad. If you white balance on a slate that is of such a greenish/blue tint, this should negate the need for a color correction filter. If you use a perfectly white slate, then you will need to warm it up via dropping down the color correction filter.

If in the event you are using supplemental HID lighting, you are probably doing more or less macro work. With the lights on, white balance with no color correction filter against a perfectly white slate. You should not need a bluish/greenish slate. Because of the daylight color temperature of HID's, you should get the red spectrums without having to artificially warm it up with a blueish/greenish hued slate.

Some HD videographers have white balanced against the surface, against light colored sand, etc. It is more convenient, but experiment when the shot is not critical.

Slight color correction can be done in post, but better to start out with a properly white balanced baseline and tweak it than to try to majorly correct things in post.

So I'd like to hear from others how they deviate from the baseline.

Misa
02-06-2010, 12:10 PM
I`ve heard from a guy (not tested yet) if you put something white in front of the camera for 5 seconds while you are u/w it will auto w/b.

Is this true?

The Publisher
02-06-2010, 04:44 PM
I don't believe so. You have to tell the camera that what it is looking at is what white is supposed to be. When you press the button telling it to white balance, that is something that manually needs to be done. Otherwise the camera just sees colors, but does not know what to reference those colors to.

David White
02-07-2010, 04:54 PM
My standard operating procedure is to white balance with Amphibico's slate prior to just about every shot. On occasion, where I am not getting the required result I will white balance by aiming the housing at the sun. Dropping down the green colour balance in post is usually the only correction that is required while editing. For the most part, except in shallow water, I always utilize the red filter.

klemens Gann
02-08-2010, 11:58 AM
I personally don't use red filters anymore as they "swallow" too much light and I don't like getting it back through "gain" as the picture quality degrades a lot. It looks grainy which I can't stand.
In my Gates housing I have 3 white balance switches. One is preset which can be set to outdoor or indoor. I use indoor here ( which gives a bluish picture) to compensate my halogen lights. the 2 other switches are manual settings for white balance. Switch A I balance on Land to a very red tone ( this compensates for the red filter, I achive this by white balancing against a blue background)) and the switch B I adjust underwater depending on the situation. I usually use a greyish background to white balance against, in my case grey sponges work very well. This way you are pretty good with macro and white angle. Of course every day is different and if the visibility is bad it's always hard to get good results, but final cut and a lot of patience takes care of the rest. Anyhow I agree with Dave, try to get it as good as you can underwater and not in front of your computer.

Okeanos
09-22-2010, 09:04 PM
I just use the surface to set my white balance. If I want it to be a little richer in colour I reduce the angle and keep changing the angle until I get the results I want. I do the same with my stills camera and have had some half decent results.

The Publisher
09-23-2010, 05:06 AM
Nothing like color correction in post, although there is a limit to that...

I too do not like how much light the red filter removes....

klemens Gann
10-04-2010, 07:29 AM
you right Dave, 99% of the shots I have will look better after I work with them for a while on final cut. As I said I never use the red filter, I exchanged it for a +4 diopter.

Okeanos
10-04-2010, 09:31 AM
I usually do no post production of images. Maybe a crop and a little unsharp mask if I feel it needs it.

klemens Gann
08-30-2011, 03:21 PM
I just posted a video about custom white balancing underwater.