C300: Exposing Log for highlights

Finnegan

Finnegan

Well-known member

I shoot a variety show for the web called Cheap Cool Crazy and since we've got such a low turnaround time on the backend, I don't shoot Log because we simply don't have enough time to do a proper color pass -- the footage gets assembled, cut, graphics get added and it goes to final export and upload. So, I tweaked some of the stock C300 CPs and in conjunction with Brian Weed's TRU CPs, I can get the look I want almost entirely in camera, at least pretty much.

Now since most of the stuff I shoot has this low turnaround time I haven't really gotten a chance to shoot Log and take the footage through the whole process of grading it, but I have looked at the WFM in Log and seem that all the highlights fall much lower than they normally do when shooting other CPs. This, no doubt, is what Log is meant to do: preserve the highlights and shadows so that in post the colorist and make the necessary adjustments. But my question is how then do I place highlights on the waveform monitor?

For instance in the episode I linked above, I expose Naomi pretty high up on the WFM -- around 70-80% actually -- and that looks about where she should be to my eye. Again, I do this knowing that the highlights won't be adjusted for in post for lack of time. But, in the future when we maybe have more time or for projects where the color grade step is built in and I can shoot Log, do I continue to expose highlights at 70% on the WFM or allow them to fall to the 40-50% mark knowing I can bring them up in post?
 
It depends on what you want. You don't want to expose for highlights in log at the expense of your shadows. Nor do you want to compress your mids too much. I've been dealing with Log on a theoretical level so far, as I've never had the ability to really shoot it (one of the selling points of the C100 for me actually). My next project will be all Log with a DaVinci pass. But, from what I've gathered, shooting Log is not to be thought of as shooting Raw. You still need to have a target of the final look in mind, so if you primarily need the information in your mids, you need to shoot with that in mind. Not to the 70%-ish range that you would with Rec.709, but perhaps in the 50% range.

And, Sean, I've wanted to play with Log more (mostly through the Technicolor Cinestyle), but a lot of times, projects that would benefit from it are out of my hands, and mentioning Log or LUTs to the post-production team ends up with a blank look. I already have enough issues not having my footage CC'd when I hand it off...would hate to hand off Log footage and see it put up for the world with nothing done to it, so I understand about needing to bake in the look with the example above.
 
Depends on what your shooting and if blowing out the background is ok. I've pushed shots to 100 IRE in the background because the talent looked good and that mattered most plus it looks cool sometimes. I did a test in log and under exposed the shot so the gray sky wasn't blown out and the talent looked dark. It turned out to be a tough shot to grade and guess what. They used it so I have some work ahead of me. Lesson learned. Log wont save you if you dont have enough information in the mids. The added DR helps.

Here is a shot that Canon log did help with. It's in another thread so add the link. Easier than reposting the images. Click the link to the pics to see them bigger.

http://www.dvxuser.com/V6/showthrea...e-data&p=1986250530&viewfull=1#post1986250530

Tough lighting situation. I'm not used to getting. I think it looks pretty good and all I used for fill was a 40" x 40" Mathews bounce board.

These are great! http://www.msegrip.com/product/lighting-control-1/reflectors/matthews-expendable-reflectors.html I wish I had two more!

Using log has benefits but the camera delivers great images without it and if the situation doesnt warent it you could be making things more complicated for a small return. I would also hate to hand over a log shoot to an editor that doesnt know how to grade. However tweeking can be done with a simple 3-way color corection.
 
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Erik, what were the IRE facial tones on the shoot where the 'talent looked too dark?'

I'm gathering that if your shooting LOG then expose facial tones at 50 IRE, facial highlights maxing out at 60 IRE. Then in post we can make them pop out while holding highlight and shadow detail. Ya?
 
jonnyh1968 said:
I'm gathering that if your shooting LOG then expose facial tones at 50 IRE, facial highlights maxing out at 60 IRE. Then in post we can make them pop out while holding highlight and shadow detail. Ya?
Click to expand...

This is what I'm getting as well -- that the art of Log lies in the ability to look at the footage you're getting and know that though it looks under exposed that you'll be able to adjust the highlights to your liking without problem in post production. It seems to be a matter of just running the proper tests and getting a good sense for how big that range actually is.
 
Canon C-Log is pretty similar to Panasonic Film-Rec gamma. Film-Rec has a total DR of 600%, C-Log 800%. Expose 18% gray to 38-40 IRE, reflected white at 70 IRE, this gives 30 IRE of highlight protection. Anglo flesh is around a stop higher than 18% gray in C-Log, but flesh has a range, of course.
 
Just got back from a training class on C300 and C500 given by AbelCine. Instructor recommends shooting C-Log at 32 IRE for exteriors, using an 18% gray card and 40 IRE for interiors.
 
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