Classroom lighting: SLOG2?

[Jeroen Wolf]

I have a shoot coming up in a school. There'll be a lot of neon light and daylight in the classroom, I assume. I've been experimenting with different gamma settings on my FS7 but I'm still unsure if SLOG2 (in Cine EI) would be the best option for these types of situations.

Anyone care to reflect/share their experience?

[Olof Ekbergh]

The decision of how to shoot is really based on what dynamic range you need.

This is easy to figure out, either with a light meter, if you have one and know how to use it. Or by using scopes.

If you have 7 stops or less dynamic range shoot REC709
If you have 8-12 stops use a HyperGamma.
If you have 13 or more stops, use Slog CineEI.

These are just guide lines. Experiment.

More problematic may be the color balance in mixed light. Once again experiment. Go there the day before the shoot and try different setups, than go back to your NLE/CC suite and see what works the best. Then you will know. Neon and LED lights can be a nightmare, (did you really mean Neon or do you mean fluorescent, they tend to be a bit green).

I always try to shoot in Custom. Because you can WYSIWYG the images on a good field monitor. I use the Odyssey 7Q+, then you can easily figure out a custom setup or see a LUT version of Log.

[Jeroen Wolf]

Thanks, Olof, iI like the way you break that down.

I don't have a light meter nor would I know how to use it...

How would you determine dynamic range with scopes?

And you were right, it's fluorescent light, not neon. (that was a direct translation from Dutch)

I know fluorescent is a nightmare- and especially when mixed with daylight and that's why I asked.

I don't have time to visit. This is quick in and out. I think I'll go Custom with Hypergamma's, just to be on the relatively safe side. I don't have an external monitor; I use the VF on the FS7.

I still have a lot of experimenting to do- but you can't simulate every situation. I need to go to work with this camera. (dare I say make money and experiment at the same time?! It's a calculated risk :-)

[Dave Sperling]

Neon light ??? -- Do you mean fluorescent??
First questions are - how different are the interior lighting colors from the daylight coming through the windows? Is the difference in colors a problem?
Are they using a projector in the classroom? (Most of the classrooms I've shot docu footage in lately have used one) We need to limit light to make screen contrast/ image quality better.
We usually try to control the daylight coming in so as not to wash out the screen - and try to get the color temperatures closer to each other, sometimes killing the overheads and using HMI & Daylight LED lighting instead.
Are the skin tones / uniforms of the students light of dark? / are they moving all over the classroom or staying at their desks? Is gelling the windows an option? Are you trying to maintain detail outside the windows or can they burn out?

Have you done a lot of color correcting of s-log2? Many people find it more difficult to correct than s-log 3.

[Jeroen Wolf]

Thanks for your input, Dave. I guess our posts crossed because I answered a number of your questions in my previous post.
The beamer is going to look washed out. No time to use gels.No time to do anything other than make the best out of the (short) situation, really.

The teacher is an important charachter to follow. I'll give her a lav and it would be nice if I could get a few interesting quotes from her. And I can shoot a few students/class situations at random for illustration purposes. It's all b-roll, really. I'll be shooting a few interviews with natural light or an on-camera light as my main light source.

I am quite unfamilair with grading. I use FCP X and have installed LUT Utility and have slapped some LUT's on the SLOG footage. Daylight footage is much easier to grade than tungsten lit video, I've discovered. Particularly skin tone. Interesting that you don't find a lot of tutorials on grading skin tone with SLOG footage shot with lamps and or uncontrolled lighting. Probably because it makes more sense shooting Hypergamma or REC709.

I shoot alone, by the way, and need to move fast.

[Dave Sperling]

So my advice is...
Position yourself on the windows side of the room so you don't have to deal with seeing overexposed windows. If there are windows visible, use shades or posters to block parts.
Turn off the overhead lights - that will eliminate mixed color problems.
Use a hypergamma rather than s-log because it will be easier for you to correct if you're not good with s-log.
Add a little fill from a daylight-colored source if you can (even a 1x1 LED can be a big help).

That's what I would do. Others may have different ideas.

[Jeroen Wolf]

Thanks, Dave. Things worked out pretty good in HG8. Got some CC work to do- depending on what angle you shoot, colors change quite a bit. But there was nothing I could do about that. Add to that the fact that most high school classrooms are pretty boring visually and the result will never be 'eye-candy'...

But I'm very happy with the interviews. Shot in STD5 with available light with the Canon FD 50mm 1.4, it sure makes up for the rather drab classroom footage.