Flash and Gels - Advice needed

I always gel to match the room lighting if shooting indoors - with a full CT orange gel.

Instead of thinking about your light sources in absolute terms of "cool" and "warm", try to think of your light temperature in relative terms. If you have multiple light sources, they're going to be the same temperature (multiple strobes, a strobe and the sun, a strobe gelled orange and a tungsten light), or one will be warmer and the other cooler (an ungelled flash will be cooler than a tungsten light, sunlight from a window will be cooler than tungsten light).

If you have two light sources of different temperature, you adjust the temperature of your image to make one of them "white" while the other becomes cool or warm, depending on where it is relative to the first light source.

The short answer is that if you have two light sources, and they're the strobe and the sun, you shouldn't need to gel the flash because they're the same temp. The sunlight coming through the window might be slightly cooler, but not appreciably (as indirect sunlight is cooler than direct sunlight).

What you really should do is try all possible combinations. Try it gelled and ungelled. It's the best way for you to understand what I'm trying to explain.

Rob, you can certainly try this to see if you like the results. It hasn't been a problem for me in bright sun. I have started gelling my flash with bastard amber or 1/2 CTO orange for indoor work in tungsten lighting, and then set my camera for tungsten. With window light, the biggest problem is the orange cast that tungsten lighting inside casts on the non-window light side of your subject. I've had this happen in churches. It's best to turn off the church lights and use a big white reflector to balance the shadows, or gently fill with strobes/softboxes if you can.

I'd go try your ideas beforehand and get it all worked out in advance, whatever you want to try.

rob - I dont' usually get ornage on my flash when shooting into the sun, but I imagine it would be helpful.

if the light indoors is tungsten, I will sometimes gel orange and let the windows go blue. I sort of like the effect, personally. I also sometimes not gel and let the indoor lights stay orange - a lot of people respond to the resulting warmth of the image.

When shooting in churches, I'm not so put off by the bluish window light, but more so when my flash color temp doesn't match the tungsten-lit background, and you get that weird mix of daylight, flash illumination, and the amber tungsten lit background. I feel it's better when you can warm up your flash to match the tungsten, and if you get a bluish window light, it's no biggie. I guess I'm shooting for the effect of making it look natural, like when you're there seeing it for yourself.

I don't feel the need to gel the flash when using it as fill in sunlight. Toward sunset, maybe, and for shots of people against a strong sunset sky, possibly. This is up to you. Flash K temp is usually pretty close to daylight/sunlight.

As for the windows indoors, I don't do that. I gel the flash with CTO if I want the tungsten light to be less strongly yellow/orange, but I only partially gel, because I like the warmish glow. Most of the time I gel for tungsten at night time receptions in rooms where daylight isn't competing for the dominant light. At day time receptions where there is a good amount of daylight illuminating the room, I don't usually gel at all. You can use flash a bit more dominantly to bring the K temp back toward daylight. If you get into gelling for backlit windows, I think you'll run into problems with mixed lighting in spots and will have to be ripping gels off and putting them on more than just a couple times during the event.

CTO (orange gel) is for use with tungsten lights, not sun.

A standard flash is balanced to sunlight typically and the color temp of most on cam units is around the 5200k - 5600k mark.

If you are in fluorescent lighting, you will need the green range.

Personally, I only gel for tungsten and even then I only normally use 1/2 CT-S.

Where's a good place to buy gel's from?

B&H.