Gel/balance question

I shoot a lot of action in gyms, both ambient and flash. Generally, in those circumstances, I am not mixing the light at all- its either one or the other.

Recently a team I shot had their "senior night" ceremony- the seniors are introduced and presented an award at center court. For this, I decided to try to balance the flash with the ambient to make things look natural. This was my process-

I shot a frame with daylight white balance. The shot looked yellow and gross, but that told me that the ambient light had a yellow tint. I experimented with 1/2 & full CTO gels, and decided that I liked the full CTO best.

Shot the real photos in RAW so I would have some flexibility in the white balance in post. Flash was on camera, set to ETTL. The camera was in manual, set to underexpose by about a stop. Experimenting in the camera showed that the tungsten white balance gave the closest results to what we were actually seeing.

Once in post (LR3 & CS5) I was able to tweak the white balance further to get results that I liked. Here is an example of the final result-

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That's looking pretty good. For more precise control you can calculate mired shift needed. Here's a calculator.

Interesting! So if I know that this gym is about 3800k, and I am trying to balance with a flash that is 6500k or so (I think) I can enter those values, and it is coming back with about 1/2 to 3/4 CTO.... Probably about where I eyeballed it. Any way to use something like that in the field?

sfinkernagel wrote in post #11808563
Interesting! So if I know that this gym is about 3800k, and I am trying to balance with a flash that is 6500k or so (I think) I can enter those values, and it is coming back with about 1/2 to 3/4 CTO.... Probably about where I eyeballed it. Any way to use something like that in the field?

i have the strobist gel pack, but what is the term 1/2 to 3/4 CTO mean? sorry for the newbie question.

way7837 wrote in post #11809740
i have the strobist gel pack, but what is the term 1/2 to 3/4 CTO mean? sorry for the newbie question.

The CTO describes (is the "name" of) a particular orange color. The 1/2, 3/4, or full describe the density of the color in the gel.

CTO = Color Temperature Orange

similarly, CTB = color temperature blue, etc etc.

aaron.dunlap wrote in post #11810157
CTO = Color Temperature Orange

similarly, CTB = color temperature blue, etc etc.

thanks. what does these increments mean in terms of the gels? example ... 1/2 or 3/4 CTO?

way7837 wrote in post #11810410
thanks. what does these increments mean in terms of the gels? example ... 1/2 or 3/4 CTO?

Thanks Skip. I didn't see your reply.

sfinkernagel wrote in post #11808563
Interesting! So if I know that this gym is about 3800k, and I am trying to balance with a flash that is 6500k or so (I think) I can enter those values, and it is coming back with about 1/2 to 3/4 CTO.... Probably about where I eyeballed it. Any way to use something like that in the field?

I don't think you need a calculator or anything like that in the field. I keep a "note" on my iPhone with the following reminder:

Color temperature
7,000-8,000 shade
6,000-6,500 cloudy
5,500 electronic flash
5,200-5,500 direct sunlight
4,000 white fluorescent
3,500 early morning/late afternoon
3,400 tungsten light
3,000 sunrise/sunset
2,800 domestic tungsten bulb
2,500 torch bulb
1,800-2,000 candle flame

Setting aside fluorescent for a moment, I'm starting at 5,500 for the flash, if I'm trying to match a higher temp I'm going to gel with blue, down in temp, orange. Its only a matter of degree after that and probably doesn't need to be that precise.

For example you'd probably do a full cut CTO for tungsten or sunrise/sunset; but maybe only 1/2 CTO for early morning. same thing the other way with blue.

Fluorescent you might need green.

BTW, I think you did a fine job on what you posted.

Thanks Celtic- That seems to make sense to me. I am going to save your list/chart for reference. Most gyms that I am in are return visits, so I can probably use the calculator for the second trip there, but I don't know that I can really expect to do much better than things worked out here.

The half, quarter, full etc. refer to strength of the color correction (and hence the amount of mired correction) and in practical use might be used to do something like balance light from outdoors with tungsten used indoors. For example it you had a tungsten source and a window at mid-day you might put something like a .6 ND + a half CTO over the window (it comes on rolls and you can apply like a window film using water and squeegee) to knock the window brightness down a couple of stops while getting the color temp to match your tungsten source. They also make tubing that goes over fluorescent tubes to get the color temp from them to better match your other sources. It's in these types of applications where the calculator has the most use.