Need help with white balance when using lights!

Hi All:

I just added new lights to my rig, twin 15 watt HIDs mounted on Loc Line arms with video heads for my Sony PD-170 in a Gates housing using a Fathom SWP-35.

OK here's my question. I'm intending to use the lights primarily for highlighting swimming marine life coming toward me. For example, sharks often come directly in on me and I'd like to light them gradually as they approach so the viewer doesn't really "see" the lighting if you understand my meaning. Basically, all around is darker, but the shark is lighter and "warmer." Highlighting bait fish to get that shimmer and flash would be another example. I'm primarily a wide angle videographer, I haven't tried the short stuff yet.

My first shot at this was 2 weeks ago. The bottom was roughly 100 FT, maybe 50 FT of viz, slightly cloudy blue water (below average for North Carolina). I had settings of an f stop at 9.6 and shutter at 100 because of the sun angle and amount of light at depth. I used a far field focus, to the limit of the visibility. The red filter was not used.

I dropped my white balance slate in, set maybe 3" in front of the lens (it still sees the whole thing), illuminated with both lights and manually white balanced off of it. I tried some view finder shots and saw all red where ever the lights lit stuff. Any wreckage was colored red. I tried repeated times to fix this, all with the same result. The camera continues to shift toward red no matter what I do.

Maybe I'm doing something wrong here?

Any help appreciated and respected...

CHEERS...

Andy

You shooting with a filter?

BTW, I'd stay below f8 for the PD170. Diffraction is obvious. Use the ND1 to maintain control of light.

You shooting with a filter?

BTW, I'd stay below f8 for the PD170. Diffraction is obvious. Use the ND1 to maintain control of light.

Nope, no red filter. Checked it twice just to make certain. I was thinking f stop might be the issue, but I was also wondering if the slate is just too close to the lens for adequate light illumination, even though it appears to be lit. Unfortunately I'm doing this in the middle of the diving season, meaning all my "learning" takes place between 100 and 170 FT. Doesn't give me much time to figure stuff out.

I'll try dropping back between f5.6 to 8 and use the NDF if the camera indicates it. I'll also try dropping a slate and doing MWB from about 3 FT away if conditions permit. Should I revert back to a shutter of 60 or can I stick with higher numbers?

As always, THANKS for the help!

Andy

Are you sure the white balance is getting a fix? If it's still flashing after you've done it then it's too far out of range and you need to try again. You should see a visible colour change when the white balance procedure completes successfully.

I have taken to white balancing with the ur filter off and the lights on and aimed at my white fins. This enables the light to travel a bit further than just holding it 3" away from the port and I have been pretty happy with the results.

Another thing I was successful at occurred last year when filming the great whites, I tried 2 methods of white balancing and both were good though I was only 15' down. I wb off the silver of the cage and was really surprised at how good it came out and then wb'd off the underbelly of a gw going overhead.

It has always been my goal to get to N.C. to film the sand tigers there. I'm very jealous.

Steve

Hi Guys:

Ya know, you three guys are always so nice to me here, I really do appreciate it.

Nick, the camera does get a fix and I do get a color shift. But, it's still all red. The slate's mounted on an arm and has worked fine for natural light, but I'm thinking what Steve is saying may have merit. I usually test in a flooded stone quarry before going to sea, but my lighting stuff came in after the season started. I do have a pair of white fins which may help, but I didn't have great success with them before. I'll try which each of you has suggested and report back.

Steve, the guy I dive with off Hatteras is a cat by the name of JT (click HERE for his website). He runs a well laid out 6 pack 40 FT boat and is a great captain. He let's you sleep on the boat during your trip, so no hotel expense. Here's the deal. Why don't we pick a date next summer. I'd suggest late June or middle of July. I'm pretty sure we can book the boat for 4 days, Thu through Sun. We can do all the major wrecks, down to about 160 provided you have deco experience. You fly into Raleigh, NC, I'll come pick you up and we'll be sipping a cold one on the boat in under 3 hours. I'll even provide the tanks, but you gotta buy your own gas. I'm sure we can get enough people to fill all 4 days.

Of course, some video tips would be appreciated!

Oh, BTW, here's a sample of the action you WILL get to see (linked from JT's website):

Here's the link to our latest dive a couple of weeks ago documented on JT's website:

http://www.capt-jt.com/photos_up_071109b.htm

(scroll to the bottom for the GOOD stuff...)

Just give me a date...

THANKS...

Andy

In theory, Steve's method of white balancing off something further away (e.g. white fins instead of a slate near your port) is going to make the footage even redder. Not saying it's a bad method but it would have the opposite effect from the one you want in this case.

Personally I barely ever try this type of shot because my halogens aren't bright enough for it so I generally use available light+CC filter+MWB for wide shots. But when I do I switch my lights on for wide shots I usually set WB to auto (and take the filter out). On the PD-170 you will probably find very little difference between AWB and MWB (on a white surface with lights) when you have no CC filter in, and the AWB is so much easier, leaving you free to concentrate on exposure, focus, framing, buoyancy, not getting bitten etc. etc.. You can always tweak colours in post.

You are filling the frame with the slate, right? If you don't then that might explain the redness.

I know a guy whose VX2000's MWB had a mind of its own. It maybe that you have a faulty cam. Do loads of tests topside to check it, by doing a MWB on various coloured surfaces.

Nick, When I wb off the fins, I also zoom in to the fins so that they fill the frame and then wb. No issues with the reddish footage.

Drewski.....it sounds like a good plan to me...will look at the url you listed. Stay in touch on this.

Steve

Yes Steve, and that's the same way I used to white balance successfully (although I preferred slightly pink fins) before I started using the palm of my hand. What I meant is that anything that makes the light travel further will make that light lose more red and so a MWB will add more red. In this case we're only talking about two body lengths (light from his lights travelling down to the fins and back to the camera) but if he's trying to reduce the red then this would be counter-productive, in theory.

However it might be that his lights aren't fully illuminating his slate when it's close to the camera, but would more fully illuminate his fins, and so the reverse might be true.

Wait, you say you have HID lights you want to use to illuminate the subject. HID is usually from 5600-6500°K. Just put it in daylight setting or manual set to the color temp. It should be fine that way. Color correct afterwards to fine tune.