Jump to content


Photo
- - - - -

White Balance at depth


  • Please log in to reply
10 replies to this topic

#1 Seadebbie

Seadebbie

    Starfish

  • Member
  • Pip
  • 6 posts
  • Gender:Female

Posted 15 November 2012 - 03:16 PM

I have shot with a Sony HC9 in a Gates Housing and am now using a Sony XR550v in a Gates Housing. I have always used the appropriate color correcting lens for fresh or salt water. I have had trouble in the past getting white balance below 40 feet using ambient light. I prefer to shoot ambient light. I have been able to fix white balance in post but wish I could get it closer to right when shooting. My husband found something on this forum a year ago or so about setting the white balance on brown sponges in the ocean. Any help or suggestions would be greatly appreciated. I am going on vacation next week on the M/Y Carib Dancer in the Bahamas and would like to try some of your suggested techniques and then let you know the results.
Keep Blowing Bubbles,
SeaDebbie

#2 Lwang

Lwang

    Triggerfish

  • Member
  • Pip
  • 44 posts

Posted 15 November 2012 - 07:22 PM

Does this video jig have white balance memory? If so, you can set your white balances at the preferred depth/distance and save it in memory so those specific ones could be recalled when needed.

There are many ways to do WB, I've done a whole bunch of variations, including aiming at the sand that's roughly the same distance to your subject, to aiming at the sun from the depth you are shooting. One way I found to work pretty well is to find an old picture or video one shot at certain depth that was not white balanced, aim your camera at a spot that you think should be considered neutral white/grey and set white balance on it and save it in memory. You can even search the interweb for pictures that were not corrected and do WB on that. You can then aim the camera at the pix again and see how a corrected image would look. With this technique, you could perform trial and error on different part of the image until you got what you think is a good color balance.

#3 Nick Hope

Nick Hope

    Sperm Whale

  • Industry
  • PipPipPipPipPip
  • 1966 posts
  • Gender:Male
  • Location:Thailand

Posted 15 November 2012 - 08:22 PM

With my old Sony Z1 HDV camera I white balance on the palm of my hand, normally through the UR-PRO blue water filter. If I have descended too far without white balancing, sometimes I can "help it along" by white balancing on the sun, and then on my palm. Small leaps are easier than large ones.

#4 peterbkk

peterbkk

    Tiger Shark

  • Member
  • PipPipPipPip
  • 671 posts
  • Gender:Male
  • Location:Singapore
  • Interests:Scuba Diving, Photographry Underwater Video.

Posted 16 November 2012 - 01:29 AM

My husband found something on this forum a year ago or so about setting the white balance on brown sponges in the ocean. Any help or suggestions would be greatly appreciated.


Hi Debbie,

That would be me who suggested "brown" corals or sponges.

There are two related problems in play with these Sony camcorders with white balance when underwater.

1. Lack of light to do a manual white balance (MWB)

The 550 needs a lot of light or the MWB just blinks at you...

Two options: add some light or MWB off the sun. If you prefer ambient light, you might try the second approach. The most light is coming straight from the sun, so you can try pointing the camera upwards at the sun and do a white balance off the sun. This might work. I've never had much success.

Don't use the red filter. It does not add red. Just reduces green and blue = less light -> MWB won't work.

2. Camcorder over-reacts to the absence of red

Some Sony camcorders seem to have this problem, especially the 550. If you do a manual white balance off something white or neutral, the camcorder can't find enough red so it tries to boost the red channel. It must be increasing the "gain" on the red channel. The end result is ugly red fuzzies floating all over the blue backgrounds. The solution is to do the manual white balance off something that already has a lot of red in it, like a brown sponge or coral. Maybe pink skin. But, if there is not enough light, you are back to the first problem.

One solution is to take down a small bright light like the Sola 1000 or a focus light. Shine that on a brown coral and use that patch of light as part of the MWB subject area for the manual white balance. It wont be perfect, but, if you can find an optimal balance so that you have just enough artificial light to help the camcorder do a MWB, without overpowering the ambient light, you will get closer to a better white balance than just shooting on a "daylight" setting and fixing it all in post. I became quite skilled at this balancing act with the 550.

Since then, I've moved on and now use the Canon XF100 underwater. One great XF100 feature is 4 preset WB settings. I just step through these until I find the one closest to the situation.

1 = Daylight (close to the surface)
2 = 6500 kelvin (5 meters to 15 meters)
3 = 7500 kelvin and set to reduce blue
4 = 8000 kelvin and set to reduce green

These days I rarely do anything other than the slightest tweaks in post.

Regards
Peter

#5 Seadebbie

Seadebbie

    Starfish

  • Member
  • Pip
  • 6 posts
  • Gender:Female

Posted 17 November 2012 - 05:04 AM

Thank you Peter. I think this will help. I seem to get purple water after about 40 feet too. If I white balance every ten feet or so on the way down it also works better. Sometimes I can get pretty good white balance like that. If I don't do that and just try at deeper depths….. well I'm not satisfied. I seem to struggle a little more with different things on this 550. More than I did with the HC9. In some ways I feel like the HC9 is a better camera. Just didn't really like dealing with the tapes. When I get back from vacation I'll let you know how I did.
Thanks again.
SeaDebbie

#6 Seadebbie

Seadebbie

    Starfish

  • Member
  • Pip
  • 6 posts
  • Gender:Female

Posted 20 November 2012 - 01:53 PM


This is what I struggle with. Maybe because the water is further away than the main subject matter.

#7 peterbkk

peterbkk

    Tiger Shark

  • Member
  • PipPipPipPip
  • 671 posts
  • Gender:Male
  • Location:Singapore
  • Interests:Scuba Diving, Photographry Underwater Video.

Posted 20 November 2012 - 05:11 PM

Hi Debbie,

I remember that purple color well from my CX550 days.

My theory is that some bright spark in Sony decided that, if one of the RGB channels was low, the camera should automatically boost the gain on that channel. UW, of course, that channel is red. Hence that ugly purple color and, if you look closely, dancing red fuzzies in the blue backgrounds. Remember that the camera is programmed to try to WB so that white is white. And that is impossible underwater. There is no white because red is missing. There is only blue-green.

What I used to do below 15 meters was find something with some red in it (rust, coral, skin), shine a video light on some of it (about half coverage of video light and half coverage of ambient light), and try to find a WB that compensated for some of the ambient light but did not cause that purple. I learned to see on the monitor when the camera was trying to push WB too far. If so, try again with more video light. Of course, this can be a bit time consuming and frustrating. After a few times, I learned how to get it right in a couple of attempts. Then I'd leave it unchanged for the rest of the time at that depth range, only re-balancing when I got back towards the surface.

Regards
Peter

Edited by peterbkk, 20 November 2012 - 05:13 PM.


#8 Seadebbie

Seadebbie

    Starfish

  • Member
  • Pip
  • 6 posts
  • Gender:Female

Posted 20 November 2012 - 05:48 PM

Thank you Peter, I think that will help. We'll see as I leave for the Bahamas on Saturday for a week on the Carib Dancer. I'll let you know. Thanks again.

#9 Nick Hope

Nick Hope

    Sperm Whale

  • Industry
  • PipPipPipPipPip
  • 1966 posts
  • Gender:Male
  • Location:Thailand

Posted 20 November 2012 - 10:26 PM

Looks like that camera & conditions needs a filter more in the yellow-gold-orange range of the spectrum than the regular blue water filters. You could maybe try to get one of those, or experiment with lighting gel. Or try manually white balancing on something in the pale-purple range.

#10 peterbkk

peterbkk

    Tiger Shark

  • Member
  • PipPipPipPip
  • 671 posts
  • Gender:Male
  • Location:Singapore
  • Interests:Scuba Diving, Photographry Underwater Video.

Posted 21 November 2012 - 04:48 AM

Looks like that camera & conditions needs a filter more in the yellow-gold-orange range of the spectrum than the regular blue water filters. You could maybe try to get one of those, or experiment with lighting gel. Or try manually white balancing on something in the pale-purple range.


I think that would just make it worse. The 550 needs a lot of light and at least some red to get a suitable white balance. Believe me, I tried dozens of techniques and settled on the one that works: find something with some red in it (rust, coral, skin, pink fin), shine a video light on some of it (about 50% coverage of video light and 50% coverage of ambient light), then trigger a MWB. Check the result in the monitor. If it looks about right, leave the MWB at that setting for the rest of the dive at that depth range. If it looks too purple, try again with more video light and less ambient light.

#11 r4e

r4e

    Wolf Eel

  • Member
  • PipPip
  • 141 posts
  • Gender:Male
  • Location:Southern Finland

Posted 21 November 2012 - 05:34 AM

Another choice is to white balance during descend at 10 or 15 meters whilst it still is possible, and keep that setting until you reascend to shallower waters. When you go deeper, the water becomes bluer on the video, but, that could/should be a desired result if you plan to use natural lighting. If you plan to use your torch, WB with it and use your pinkish palm as a white slate. This should fool Sony's automatic red boost. If you are desperate, e.g. you forgot to WB at 10/15 meters, you could select WB via the preset selection "Outdoors". Even that is far better than the red noise.

vimeo.com/r4e

http://www.cerella.fi for the Underwater Photographer and Videographer