I still don't understand the WB thing...

Okay, I understand all the stuff about temperature and color, etc.

What I don't understand is correcting WB at depth.

I shoot in TIFF or JPEG with my Sea & Sea, so WB matters. Using AUTO WB when shooting in ambient light, I get crappy green photos. I can make reasonable color corrections in Photoshop using the Mandrake process, but the color is still not the greatest. Not like when I am able to shoot with the flash.

I tried correcting WB at depth. I carried a white card with me. I still got crappy green photos. But the photos could not be fixed at all. I'm pretty good with Photoshop, and even I couldn't get any reasonable color corrections. When you make a WB correction at depth, the Mandrake process will not work at all.

So if you're not shooting in raw, what's the point of correcting WB at depth? It's not like you're going to magically get beautiful, color-correct photos. All you get is a crappy green photos that are impossible to correct. At least if you leave WB in AUTO you can get some reasonable color corrections.

Hi Harry

How deep are you doing this? Do you have a magic filter or other red filter?

manual WB is best done 50 feet and shallower, doesn't work well any deeper than that.

Also, a filter will really help as it helps bring the colour spectrum back to a reasonable size, if you don't use a filter the spectrum really has to stretch a lot and it doesn't work all that well any deeper than about 20 feet as the red is too far gone.

Also, you need to shoot with the sun behind you to help put some colour in there

So if you're not shooting in raw, what's the point of correcting WB at depth?

Quite the opposite, as I understand it: I was under the impression that if you're shooting raw, you specifically don't need to white balance, since each shot is balanced in post. Isn't that correct?

White balancing (when shooting jgp or tif, or video) can help tremendously, but only in the right circumstances, such as some of those Mike points out above. It's no cure-all ... at some point, there isn't any red in the water left to balance out, period, even if the water is clear enough to allow visible light at your depth, beyond a certain point, none of that visible light is red (or any of the other colors, until you arrive on the blue/green end of the spectrum).

Incidentally, I find I have more consistent results when I set my WB to "Sunny" or "Cloudy" (depending on individual lighting circumstances) instead of "Auto". Auto can vary wildly, depending on what the camera's electronics pay attention to at the moment, and what's filling your screen at the moment, even when recomposing the same basic shot.

When you are using RAW you don't need to WB (although I have also heard you should do it). I take all my pics in RAW and do the WBing at home.

What you may also want to try is this:

It worked very well on my bad cyan pictures

When you are using RAW you don't need to WB (although I have also heard you should do it). I take all my pics in RAW and do the WBing at home.

With raw you can "postpone" WB until post processing, just take a raw exposure of the grey/white-card at the actual depth before/after shooting your subject, making sure not expose the card properly. Then correct your reference photo and copy setting to your real photos. Only reason for doing it live, it to get a impression on the camerascreen on what the end result could look like.

Thanks.

I have tried correcting WB at depths ranging from 35 feet to 100 feet. I corrected WB every time I made a significant depth change.

I have not used a filter, I am not even sure how I would attached a filter to my camera. Would I just manually hold it over the lens?

I've never used RAW, have been reading about it. The books say that you don't need to correct WB when shooting RAW, but doing so makes the Photoshop corrections easier.

So from what I understand, when shooting TIFF or JPEG there's really no point correcting WB except at shallow depths, and I should probable get a filter for shooting ambient light.

Is that correct?

RAW gives you all of the unfiltered data. A jpeg and tiff are both processed by your camera. Post RAW processing works outstanding for your subject exposure but will leave something to want in the background. I read an interesting article by Alex Mustard some time back about muddy blues. When I went back to look at my RAW photos the blues were "muddy" or drab. They were certainly not like the blues I see posted here. Oskar's suggestion above is something I haven't tried but might give it a go. Since each camera's internal processing is somewhat different, it is tough to say do this or that, unless you've owned the camera and know what works. However I have heard that the WB setting of "cloudy" usually works best. With manual WB at any depth you're supposed to white balance on something the same distance as your subject. So if you're going to shoot a subject at 6ft away, you should theoretically WB on sand or some other neutral color at about 6ft away to get the optimum results. In many cases this is just impractical (Me the vacation diver who loves to shoot photos). So I usually shoot Jpeg and RAW....Jpeg as a benchmark and then RAW to save the one photo exposure I messed up but loved the photo nonetheless. With all that said, nothing beats knowing and experimenting with your camera to find out what settings work best for you and the setup you have.

Cheers,

Gary

Red light is filtered out by water so as you go deeper there just isn't enough red to get a good "balance" of the spectrum. White balance is basically telling your camera "this is what white should look like down here - now fix all the colors accordingly." It just doesn't work if there isn't a balance to begin with.

Shooting RAW helps a LOT especially if you can shoot raw+jpeg - then you get the best of both worlds.

Definitely check out some of Alex's articles on this subject - they are superb.

Cheers

James

Whatever Mandrake is the link did not work, got 404.

You mention that your pix are too green. I am posting this screen grab out of Lightroom 2 showing before and after versions of one of my shots that had too much green. Look at the upper right - there are two sliders. The blue-yellow one is for the color temperature while the green-magenta one is called tint. This latter slider is adjusted to +95 units to correct for the green. Look for a similar control in your software. You may have to shift the color temp after shifting tint. I generally have to re-iterate adjusting both sliders several times to get what I like.

This is a natural light shot. I wrote about it a bit in the available light thread. http://wetpixel.com/forums/index.php?showt...mp;#entry234476

I also did a version in LR3 beta that is in post 163 of the thread

At 10 meters 95% of the red is gone. The white balance is simply the two color correcting slides in the above post. In RAW you actually have those two sliders and you adjust them to get the picture to look like you want.

If the red is largely gone you need to move some of the other color into the red channel to simulate more red.

What filters do is REDUCE the colors other than red to repair the balance.

At 10 meters 95% of the red is gone. The white balance is simply the two color correcting slides in the above post. In RAW you actually have those two sliders and you adjust them to get the picture to look like you want.

 

If the red is largely gone you need to move some of the other color into the red channel to simulate more red.

 

What filters do is REDUCE the colors other than red to repair the balance.

Correct, there is a practical depth limitation to how much WB can be done even on a raw image such as I showed above, which was from near the surface down to maybe 3 m. It was well over 1 m deep where I stood (in waders) and pushed the rig in and deeper still where it was sitting when I took the shot, and deeper still in front of the lens.

If one does a WB on a too deep shot to get rid of blue, one ends up with almost a black and white image. I have seen this as well when printing color negatives in the conventional darkroom.

Whatever Mandrake is the link did not work, got 404.

 

You mention that your pix are too green. I am posting this screen grab out of Lightroom 2 showing before and after versions of one of my shots that had too much green. Look at the upper right - there are two sliders. The blue-yellow one is for the color temperature while the green-magenta one is called tint. This latter slider is adjusted to +95 units to correct for the green. Look for a similar control in your software. You may have to shift the color temp after shifting tint. I generally have to re-iterate adjusting both sliders several times to get what I like.

 

This is a natural light shot. I wrote about it a bit in the available light thread. http://wetpixel.com/forums/index.php?showt...mp;#entry234476

I also did a version in LR3 beta that is in post 163 of the thread

Thank you. But I don't use Lightroom, I use Photoshop CS2.

If the red is largely gone you need to move some of the other color into the red channel to simulate more red...

This is precisely what the Mandrake Process does.

Here's a link to the Mandrake Method action file for Photoshop:

http://www.adobe.com/cfusion/exchange/inde...p;extid=1042430

Works on pretty much all versions, 6.0 and higher. (I know it worked in 6-7-CS-CS2-CS3, I actually haven't tried it in CS4, but I assume is still works)

More info on it in this thread: http://www.scubaboard.com/forums/tips-tech...no-strobes.html

I have a Sea & Sea DX-1G and I have the WB set to 'Cloudy' and it works a treat for me and at the moment I shoot in JPEG - as a couple of the others have said this maybe an option to try.

Karl

Thank you. But I don't use Lightroom, I use Photoshop CS2.

Here is a screengrab of CS2. The tint slider is at +25.

Hi Tom,

Just wanted to comment that I really like this shot!