White balance

[MikeC]

I am happy to shoot using auto white balance with an orange filter and then in post, color correct to suit my eye.

Rick, PLEASE repeat after me VECTORSCOPE. The eye is easily tricked. One of the best editors I know is colorblind, he did not trust his eyes, only 'scopes.

Yes, I know that what may be technically correct, doesn't look right. I cheat when I paint cameras too.

 

[PerroneFord]

MikeC, spot on. Which is why I mentioned colorbars. I stopped short of recommending laminated warming cards which is eXACTLY what would be needed underwater, but I digress.

Colorbars and a vectorscope will put your videos into a new realm in terms of color balance. I scope every video I shoot now. And every one gets bars in the leader.

 

[RickSp]

Rick, PLEASE repeat after me VECTORSCOPE. The eye is easily tricked. One of the best editors I know is colorblind, he did not trust his eyes, only 'scopes.

Yes, I know that what may be technically correct, doesn't look right. I cheat when I paint cameras too.

Ah, yah? Of course, I use a vectorscope when color correcting. A vectorscope is fine, as far as it goes, but is hardly the be all and end all of color correction. I've got lots of great tools, but what the video looks like is after all the purpose of the exercise.

I have never shot underwater... however, basic video color theory should apply.

Not exactly. Water is thicker than air so light and color can differ widely not only with depth but also with focal length. Air is clear (relatively). Water is not.

Ron, perhaps when I am more comfortable shooting underwater I may switch to manual WB. Until, then I will probably continue to shoot auto and tweek it in post.

 

[PerroneFord]

RickSp,

While it is true that that water affects color depending on both depth and distance from target, balancing the colors shoudln't be all that much different. If you've ever shot film or video on a hazy day, the water vapor in the air affects the exposure in much the same way we are talking about here, though not to the same extent.

It seems to me, that if you rebalance the camera (white, black, and color bar) your videos will stand a FAR better chance of looking more realistic than if you don't. Particularly for those without strong post skills. While it's clear you know what you're doing in post, the average consumer may never have heard the term colorbar or vectorscope or know what they are for. They don't know IRE values and how to adjust their ranges for proper contrast, and brightness.

So like most things, those people who know the most about the subject can often get by without some of the tools because we know how to correct for them. Where beginners or those without experience in video post, could benefit greatly.

One day, I hope to shoot underwater and experience all these headaches! This has been a very informative and productive thread.

 

[ronrosa]

One day, I hope to shoot underwater and experience all these headaches! This has been a very informative and productive thread.

Sounds like you are into video and/or photo and obviously you dive.

What are you waiting for ?

To me, the next best thing to diving, is watching video that I've recorded with my own two hands and edited to my musical tastes.

 

[ScubaBob92651]

Question for all those that manually white balance underwater. I've seen at least one (Amphibico I believe) white balance slate that has a blue tint to it. For those that color balance underwater - what do you use? White balance card? Dive Slate? Amphibico type white balance slate? Thanks!

 

[PerroneFord]

Sounds like you are into video and/or photo and obviously you dive.

What are you waiting for ?

To me, the next best thing to diving, is watching video that I've recorded with my own two hands and edited to my musical tastes.

I'm not a diver, yet. I am certified, but am nowhere near good enough to be fiddling with a camera under the water. Maybe in a year.

 

[PerroneFord]

Question for all those that manually white balance underwater. I've seen at least one (Amphibico I believe) white balance slate that has a blue tint to it. For those that color balance underwater - what do you use? White balance card? Dive Slate? Amphibico type white balance slate? Thanks!

The idea of white balancing is to try to instruct the camera in what is "true" color. Using a slate that is slightly blue, tends to produce "cool" or "cold" colors. If you've ever looked at a car with HID headlights and notices how its light looks on the road compared to the standard halogen, that is "cool" lighting. While it may produce quite accurate colors, they tend to not be flattering

Most people who shoot, use a warming card. Which has just a very slight overbalance toward red. When shooting human subjects, this tends to make pale skin a bit nicer, and gives it a little glow. For most bright colors, it gives them a little "pop".

The other issue is that underwater, the deeper you travel, the "colder" the light gets as the red light waves get absorbed. You are losing reds, oranges, yellows, etc. The warm colors. So overbalancing the camera toward warm colors tends to offsent the "blueness" of the environment. Balancing off a "cold" card undwater just worsens the effect of being deep.

So for those doing a white balance underwater, I'd suggest a warming card instead of a pure "white" card.

 

[RickSp]

Question for all those that manually white balance underwater. I've seen at least one (Amphibico I believe) white balance slate that has a blue tint to it. For those that color balance underwater - what do you use? White balance card? Dive Slate? Amphibico type white balance slate? Thanks!

As I noted before I generally don't manually white balance underwater, nevertheless, a few comments. There are at least three ways to get reasonable color underwater. Most housings have or can fit orange or red filters which shift the colors the camera sees away from blue. They work well except in very shallow water where they do over compensate.

Depending on what camera you are shooting with you may be able to manually shift your white balance to compensate as well. So far I haven't had time enough to experiment to see whether I can do without the orange filter by shifting the white balance in my custom presets. Shifting the custom presets and using an orange filter would probably be a bad idea, serious overkill.

The third way is to manually white balance off a white or gray surface underwater. Here is where the blue tinted card is interesting. Above water you can white balance off a white or gray card and you are good to go. Underwater it isn't quite so easy.

The color white will vary as a function of the distance from your lens. Water is a lot thicker than air. If you hold a card at arm's length and manually white balance you will set up your camera for shots at arm's length. Given that most shots will be greater than arm's length, your shots may end up bluer than you might have liked. White balancing off a sandy bottom is great if you have one handy, which you may not on a reef wall. Or you could have your dive buddy hold the card at the average shot length zoom in on it and white balance manually. (Not very practical, I'll admit.)

A bluish card gets around this problem in that it slightly over compensates for the blue, effectively tricking your camera into thinking your arm is longer than it is.

 

[RickSp]

One last thought on white balance. On dry land the main reason to white balance is to correct for color temperature. Sunlight is bluer than incandesent bulbs which are slightly yellow which are different from flourescent which can introduce green. Directors and DPs can do fun things by artfully playing with white balance using warming or cooling cards to artificially bump color one way or the other. This can look great or dreadful depending on who is doing it.

This discussion brought to mind a concert I was shooting with two cameras. I find that the best way to match multiple cameras is to white balance them together. The stage hower was lit using lots of theatrical lights with various color filters. I literally had no white to balance to. (I ended up taking both cameras back stage and white balancing them together in white light. As long as their settings were both the same I could do any tweeking I wanted in post.)

This comes to mind because underwater you really are white balancing in colored light and even if manually white balancing, you can over or under compensate. In fact you probably want to over compensate slightly to make the colors in your video just slightly more brilliant than what your eyes actually see. Then again your eyes are more accute than the ccds on your camera and brain does some white balancing on its own, so maybe you are correcting just to catch the wonder that you do see down below.

There really is no such thing as "true color". More than anything else color is a function of light, how much, or how little you have, its intensity and color temperature and so on. If you white balance manually and then turn on your camera dive lights, you better white balance again. The same thing goes if your light batteries run down or when you go up or down twenty or thirty feet.

Again, my preference is to get close to the right color then tweek it all in post.

Swimming away from my soapbox now.

Rick