Light & Motion and Sony

I have a Light & Motion housing (Blue Fin) and a Sony HDR-CX550V Video camera. This is new for me and I used it on my last trip. when I try to do manual white Balance, the colors are way off, yellow snappers are flourecent green and it is horrible. I white balance every 10 feet and use a white slate and and fill the view finder with the slate. I went back to the red filter and it was a lot better. What I would like to know is what is the best settings for the camera, in order to optimize my equipment. The manual from Light and Motion was a big joke. One page. I really want to learn this system, any help?

Thanks

I really don't know why everyone insists on WB ing on a white slate, it should be a blueish one for the tropical ocean.

Just set the camera warm before you get in. That is WB it against something blue like the sky without the URPRO filter in.

It will make the up top footage redish but underwater it will be fine, then as you go deeper flip in the URPRO filter.

As long as it's close, you can easy tweak it later on the computer.

I have a Light & Motion housing (Blue Fin) and a Sony HDR-CX550V Video camera. This is new for me and I used it on my last trip. when I try to do manual white Balance, the colors are way off, yellow snappers are flourecent green and it is horrible. I white balance every 10 feet and use a white slate and and fill the view finder with the slate. I went back to the red filter and it was a lot better. What I would like to know is what is the best settings for the camera, in order to optimize my equipment. The manual from Light and Motion was a big joke. One page. I really want to learn this system, any help?

 

Thanks

Welcome to the club! There are many posts on this forum about the finicky MWB of the CX550V underwater and possible workaround.

For instance: http://wetpixel.com/forums/lofiversion/index.php/t36496.html

User peterbkk (Peter Walker) has acquired a lot of practical experience with it, although he has now moved up the ladder and uses another camera.

The bottom line is that due to loss of red light at depth and the poor red sensitivity of the sensor, if you ask the camera to compensate for both and "recreate" white, it will boost the gain of the red channel up to a level where it essentially amplifies the noise and you get a grainy red look. I personally rarely use MWB anymore (not needed with lights and close shots and pretty much useless in green water).

Concerning the use of a red filter, it is good that you've experimented with it (and even obtained satisfactory results), but you have to realize that those were invented way back then when there was little options for post processing pictures (I am not even talking about video). A filter essentially kills blues and greens (I have a post somewhere on the forum where I showed the transmission spectra of a few filters I own, and they clearly show that), leaving the red (or the little there is left of it at depth) intact. So if your scene is bright, that may still be OK, but if you have no red light to begin with, MWB will still result in a grainy red look. If you have both plenty of light and some red, then it might allow you to do a decent job. Personally I have stored my filters (I bought L&M "Green Water" filter as well) neatly in a box and plan not using them ever again...

Do not hesitate to post some of your shots if you want less general (and for the most part obvious) comments.

And enjoy the camera. It's a really good one. I love it.

I really don't know why everyone insists on WB ing on a white slate, it should be a blueish one for the tropical ocean.

 

Just set the camera warm before you get in. That is WB it against something blue like the sky without the URPRO filter in.

It will make the up top footage redish but underwater it will be fine, then as you go deeper flip in the URPRO filter.

As long as it's close, you can easy tweak it later on the computer.

For the CX550V, a redish slate helps preventing "red gain explosion". IMHO, a blueish slate won't do any good.

I don't know why they use a slate at all. If you hold up a slate in front of a port, it is likely your lights are now aimed at the slate as well. Therefore, your cam is white balancing to a well lit white very close to the cam. However, when filming, our subjects are often lit by lights a couple of feet or more away from the lights, so White in that case is not the same white when it is so close to the port.

I WB on my white fins with the lights on. In this case, I am WBing to, what I think, is a real world situation and thus is more accurate.

Steve

A quick tips on the camera settings for you to try out (which I happen to just mentioned on the other post):

- turn of auto back lighting

- turn of low lux

- decrease exposure -2

Use red filter. Use sand/coral rubbles to white balance. White balance as often as possible (every 2 feet, not 10) but with this setup max depth to white balance would be 12-15m (depending on condition). If you white balance below that it gets a bit purple-ish.

From around 5m to 25m depth you probably want to be using both the CC filter and manual white balance. Your post implies that you've been doing one or the other.

Here is some insight on how antique HDV gear responds to different types of MWB. Since those tests I've been white balancing on the palm of my hand. Below 25m I usually flip out the filter to gain some light and reduce noise-inducing gain. Shallower than 20 foot you should experiment with filter+AWB versus filter+MWB versus no-filter+MWB since any one of these combinations can look best depending on the camera and conditions.

Personally I would never use a blueish slate for MWB with my cameras. If I use a white slate I have to reduce the red on the computer and it would be worse with a blueish slate. By using my hand I can usually get away with no color correction, and it's usually easier to find than a slate.

I don't like white balancing on sand either. I get a purplish result, which is logical since sand is yellowish, which is the complimentary of purple.

So there you go. Some wildly differing white balance advice for you to test. My advice is to get down to 15-20m and try a load of options out like I did and compare the footage up-top later.