WB for 2 different light sources

[lostfx]

Hi, guys!

 

I would like to know how you deal with this problem. Imagine that you

have to shoot bride dressing up in room where are strong (tungsteen?)

spot lights. You also want to use your flash for fills. How do you

appropriatelly adjust the white balance? If you adjust it for flash

only, everything else that is not lit by flash will become abnormally

warm, if you adjust for tungsteen, then everything that is flash lit

will become cold (blue). The only way around that I found is to shoot

in RAW, and then adjust Color Temp for FLASH, then save it and then

save another copy with tungsteen adjusted and then mask those two.

 

Is there a beter way of doing it?

 

Thank you.

 

DD

[ellis_vener_photography]

<I>http://www.hindsightltd.com/index.html</I><P>The best thing to do in this situation

is to balance one of the light sources to the other. The easiest way to do this in the type of

situation you describe is to put a Rosco or Lee Filters "CTO" lighting gel over the flash.

This gel changes the color temperature of a light source by -2300K , or from 5500K to

3200K. Your basic tungsten household light bulbs, if they aren't dimmed , are about

2700K. So while you still have a color difference it isn't large and the warmer color of the

room lights works as a flattering accent. If you want a more exact match you might try

adding a 1/4 CTO as well. T oget a really precise match you'll need a Konica-Minolta Color

Temperature Meter 3F and a passle of gels. <P> Both Rosco and Lee are happy to send

you a little sampler of their filters which just happen to just large enough to cover the

head of a small camera mounted flash (Nikon SB-800 or Canon 580EX size). You can buy

larger sheets or rolls if you have larger lights. Gelling your flash makes much faster work

of color balancing than doing the two step process you outlined in your post, just

remember to remove it later.

[allen_d.]

Use multiple flashes, easier if they are wireless. Use one on camera and either put a diffuser on it or bounce it off a side wall, and have the other point straight up to the ceiling, no diffuser. Set your speed to at least 125 and don't shoot wide open and all room light will be eliminated.

[michael_madio]

It is very unlikely that the tungsten lights are powerful enough to act as key (if they were, the bride would break into a sweat while getting ready) so you won't be using your flash as fill. Using your flash as key, you should be able to bounce it off the ceiling as most dressing rooms have 8' White ceilings. Use flash white balance, and you can drag the shutter a bit if you want to register some of the ambient light.

[merlin]

gelling your flash is the easiest way, other wise you'll be doing mulitple color correction and masking different layers etc....or if it turns out real bad make it b&w

[lostfx]

Thank you guys for all your hints. I just want to point out, that I want to keep spot tungsteen lights in the scene since I want to keep the ambient atmosphere present. But if the ceiling is low it creates harsh shadows especially on people's faces staying close by. But I would like to have my flash light temperature the same as tungsteen light, so it mixes nicely. The equipment used is Canon 20D with 24-105 f4.0 lens and 580EX flash.

 

Maybe that gel would do it.

 

 

Thanks.

 

Dusan

[kari douma]

Hi Dusan, This is a very interesting post. Can you post a sample of what you are talking about? I would like to see the original image with the problem in color balance, and the one you have layered and corrected. Maybe it will help train my eye for the same problem in my own work. I would appreciate it.

Kari

[colleendonovan]

What I do is use my flash for a WB exposure. I take a picture using the flash and the lights. You just have to remember to switch WB if you turn your flash off. Maybe I'm over simplifying.

[lostfx]

I will post the picture once I get home, so you guys have an idea what I'm talking about. I was just wondering, if I can't just use a simple math to figure out close enough color temp number. I mean you add tunsgteen temp + flash temp and average these 2 numbers. The reason is that as I was trying to move color temp slider back and forth in ACR to compensate it, I've got somewhere where it actually was acceptable. It is very tricky, because if you are shooting for example in small church with your flash on and off, then you end up with walls having a different color in each case. It is not such a big deal if you look at those pictures individually, but if you lay them down next to each other then you might have a problem.

[lostfx]

I forgot to add that the best thing around this is (as somebody already mentioned) to convert it to B&W and the problem is solved. :-)

[lovcom_photo]

I would set the WB to flash, and shoot raw. Fixing WB later in PS is non-destructive to the pixels. However this solution may only work if the difference in light temperture is not great.

[paul_sokal___dallas__tx]

Count another vote for gelling. While you can set a custom WB, that's just going to give you the average temperature and you will still see two different lighting types. The results are much closer if you if you use a tungsten gel.

[picturesque]

There have been several posts about this topic in this forum already. Here is one:

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00CO4h&tag=

 

Do a search, there are others. You can get a sample pack of gels from B&H for one cent. The sample size happens to fit over most shoemount flash reflectors. I carry the 1/2, 1/4 and 1/8 CTO gel plus the green ones for flourescents in my bag.

[lostfx]

Ok, here are examples. It is actually combination of tungsteen light and daylight. Here is the extreme example, but for illustration purposes it is the best I have. First picture is corrected for proper skin color, but the outside (thru window in the back looks too blue). The next one is corrected for outside, but the skin looks too yellow/magenta - crazy warm. The third one is masked out. It is not perfect, but good enough for this example.

 

Dusan<div></div>

[lostfx]

corrected for outside... (see the window in background)<div></div>

[lostfx]

Combined and masked version....<div></div>