White balance settings on a Sony for underwater use please?

Mdemon

I'm at the Red Sea and diving with a tiny video camera for fun. It's in an old torch housing so I turn it on, put it in the housing and point it at something interesting - that's all the control I have!

Other than realising you need to keep a camera very steady underwater (!!), I have a problem; everything is blue! The pictures are fine but obviously not white balanced for underwater use. I think it's set to autoWB.

Can anyone suggest a way of setting the camera so I get something vaguely acceptable please?






(It's a microMV camcoder, quite old and v. small - haven't got the model number to hand... )

TIA!

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Lake_Tahoe_Diver

Are you using any external lights? If not, I would suggest using a red/orange filter to put the red back in to the video since we all know Red is the first color to be filter by water, hence things appear blue. Most Video cameras I find can not be set to auto correct for the lack of red. Some setting like telling them you are under tungsten or floresent lights may help since they filter out some of the blue then. That is my two cents.

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Crazyduck

Small cameras (esp. miniatures) do not have a white balance.
The ones that do require a light card to modify the white balance underwater.
You can’t do that- sealed unit.

Ask if any of the members in the group have a ‘Magic Filter.”
This filter is an orangish/ red filter developed by Alex Mustard and is more popular in England than in the states. This is one of those things that people tend to buy, try, and drop in their camera bags. Someone might lend you one.
If they have one and you can use the camera in shallow water it might help.
Link- M A G I C - F I L T E R S

Outside of that- you might be able to adjust it when you get home.

Best Regards, Andrew

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Mdemon

Thank you!

Bit late for the filters, although I tried a white card to help the autoWB along... Veryt interesting link though - may need to invest.

Will have to add the red back manually. Any suggestions what's best to do this? I have the Sony app that came with it and I've got Adobe Premiere. Haven't a clue how to use either...

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The WRONG Attitude will get you killed.

"Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"

Genesis

You can't add back what's not there in terms of signal.

If there is enough red signal in the tape, you can do this with color balance tools in all common video editing applications. I don't know how to run Premiere, but I can do it reasonably easily in Vegas.

You may, however, find that the "red" signal in the original source footage is too buried to be of much use. If that is the case then there is not much you can do about it.

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PeteS

Most of the above comments are very good, but in addition you should bear in mind that the colour correction you need changes with

1/ depth because of the red light from the surface being filtered, and

2/ with distance from the lens because any the illumination from video lights used has to travel to the subject and back to the camera, and

3/ varies from hour to hour dependent upon the amount of daylight available, and

4/ if a cloud goes over the sun when you are videoing, you camera may well change the exposure automatically, but the white balance will be screwed.

Solutions? Big floodlights. Or only work very shallow on a day with steady levels of daylight, on a subject that keeps a constant distance from the camera at a constant depth........

I guess you really need to be aware that there is not one set of numbers that work for all situations all the time. You are chasing a moving target that also changes its direction of movement!

As for correcting after videoing? If there isn't any red in the picture to start with, you've got nothing to correct with.

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PCDiver

Floodlights: I can recommend the following lights from Greenforce: HID100, or better HID250. The video version is called "Squid". They come with a reflector that creates a 110° wide beam. A set of those will probably cost more than your camerasetup. And forget using the lights on subjects that are more than 2 to 3 meters away. For that you need lights powered by a generator. Using lights during the day is much more difficult than on night dives.

Color correction. You can do amazing stuff with color correction. In Adobe you can put the three way color correction effect on the clip and adjust the balances for gray, black and white. Up to 20, perhaps even 30 meters with the typical Egypt visibility and daylight, there should be enough red to play with. In Premiere Pro you can switch the monitor to "RGB Parade" mode. This will give you an idea of the available colors.

Excessive color correction can (will) cause color banding. This will become very noticable in upward shots where you see sunlight.

Without lights you will have to use a red filter to get good results. The Magic filters were already mentioned. The URPro filters are also very good.

White balance. If your camera doesn't support manual white balance, a white card will not help. The moment you move the camera away from your white card, it will readjust the white balance settings.

You can get lots of info on several public forums. The one that I use frequently is Wetpixel.com :: Underwater Photography and Videography. They have two subforums dedicated to underwater video.

<edit, misread your post about the torch. The next paragpraph might not be relevant for you.>
You mentioned you used a torch. This torch is probably a halogen light. The color temperature of a halogen light is around 3300° Kelvin. Daylight is over 5500°. A halogen light will produce a reddish light. Combining daylight and a halogen spotlight is bad for color correction because you have two very distinctive light sources. A halogen floodlight(s) that covers the entire subject will work. I like HID or HMI (even more expensive) lights because they produce a color temperature that is closer to daylight. You can use those to fill in part of the image.

Peter

Genesis

Typical HID lamps have absolutely horrible color fidelity - in technical terms their "CRI" sucks.

On the other hand, HMI lights have absolutely horrible costs! If you have the money, then none of this matters... most mortals (myself included) deal with the CRI problem and use HIDs (I have a dual 24W HID setup on my housing which I affectionately call "Frankenlights". It works well.)

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PCDiver

Hi Karl,

Technically it is true that the CRI of most HID lights sucks. However, I have not noticed the impact of that on my footage. I guess it has to do with the "quality" of the medium, water, we film in.

decoweenie

Peter,

On the side note, I am REALLY looking forward to pick your brain about video during our coming trip, as well as it would be great to document the wrecks on your HD system.

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