C100: C100 MKI Color Profile Advice

puredrifting

puredrifting

Major Contributor
Hi all:

Shooting a sizzle for a TV show pitch this weekend, will be using our C100 MKI into our Ninja Blade as our A camera, an 80D on a gimbal as our B camera along with Go Pros for various car footage. The forecast is typical for SoCal, nuclear levels of sunshine. We are mostly shooting exteriors and some in car footage and we do not have the resources to ND the car windows. If you were DPing this shoot, would you:

1. Shoot it C-Log? The new Blade firmware has a form of HDR software built in to monitor C-Log with Rec709 but I have little experience in using C-Log. What concerns me is when I research, I see wild disparity about where to expose skin tones (shooting people of color in bright sunlight) and where to set what would normally be 100IRE zebras in C-Log. I am also concerned that I keep hearing that the C100 MKIs 8bit resolution, even though it will be recorded to 10 bit Prores HQ, is limiting with C-Log as far as noise. I don't think we will shoot much into the evening but there is a possibility of shooting some car material at golden hour and into the indigo of the evening. 80D is setup with Prolost Flat and will be shooting the Go Pros flat. But for our show concept, a mixed media look is fine, we are not concerned about trying to color match the three kinds of cameras at all. I am concerned about being able to have a few more stops of DR though since we are outside in shade but parts of the BG will be in direct sunlight.
2. Shoot it WDR? I have shot WDR quite a bit and generally, it seems to be a good compromise for material that will be graded but also wanting a look that for screeners will look passable. Is there much difference in real world DR between WDR and C-Log?

I have spoken with our editor and we were both going to shop around for some different LUTs if we shoot it in C-Log, but I don't want to overexpose images, the Blade screen will be my only way to judge exposure besides zebras and waveform. But a lot of this shoot will be run and gun, tiny crew and lots to shoot so I will not have time to eyeball and adjust a lot of the finer points of exposure. It seems to me that for the circumstances, WDR would be easier and better? Would like to hear from anyone who has shot in similar circumstances with the C100 MKI, run and gun, bright exteriors, etc. what you used for color profile and were you happy with what you shot and how post came out. I normally shoot with my own customized picture profiles that I modified from Abel Cine's profiles and I am happy with the look and clients are. But our work is rarely graded and sometimes not even color corrected for quick deadlines for press junkets. For this project, we are cutting a sizzle and will have some time so we want to get the best images possible and most DR and sharpening in post options with the limited gear we have.

Thanks for your advice.
 
I'm certainly not an expert in color profiles, but I think you'll be fine with C-log. The C100 mk1 C-log really sings in bright daylight - I think it's one of the highlights of that camera (not so much its interior color handling). And if you're going for Prolost and Protune for the other cams, C-log will match the flatness a little better than WDR.

I don't know what to tell you about the DR and IRE - we usually keep ISO at 850, ND 2 or 3, and expose using the meter and eye balls, without worrying too much if it's under or over a stop or two. Only the slightest color correction is applied in post, without a LUT, and the end result is a creamy image that is less punchy as WDR but still has great color.

Here's a few straight from the camera screengrabs of a project I'm editing right now, of a sunny day with both light and dark objects in the frame - you can decide if the shadow noise is tolerable for your needs or not.

clog1.jpgclog2.jpgclog3.jpg

Cheers,
Slavik
 
Thanks Slavik. Do you expose your skin tones normally (zebras with just a touch on the forehead or cheeks at 70-80 IRE) when shopoting C-Log? That's one thing I am totally confused by after reading about ten articles on how to expose C-Log correctly. It seems I read a lot of conflicting info about where to expose skin tones with C-Log. Everyone says 32% for a gray card but on this shoot, there is no way I will have time to meter a gray card at every setup, will be jumping in and out of cars, following people, etc so I obviously need to use zebras and the camera's meter. My main concern is that our talent looks great. If other things blow out, so be it. I looked at the "corrected" C-Log profile from N-Town and he says to expose skin at a hair under 70%, I am assuming he means 70 IRE? You don't use a LUT but a lot of people who shoot log do, the whole thing is a bit confusing. I just downloaded the latest firmware for the Blade and it has a preset for C-Log but when I switch to C-Log and view it through the Blade screen it looks SUPER contrasty and punchy with no apparent shadow detail. I may try C-Log but it makes me nervous not having shot tests with it, I may end up just using my own preset I customized from an Abel Cine preset. At least I know what I'll get and can see what I'll get.

Thanks for the advice.
 
I struggled with C-log for a long time, but I think I'm getting better with it lately.

After testing, I like to have caucasian skin tones kissing 50 IRE. That works well if you're just dropping an official Canon LUT on the footage and want it to be nearly perfect as-is. Another good rule of thumb is keeping an eye on the exposure bar at the bottom of the C100's "evf" (he said sarcastically) and LCD. I've found having the bar one notch or so to the right of the middle arrow is often a good place to be. I came up with these guidelines after buying a light meter, and doing some tests, seeing how the waveform, the exposure bar, skintones, and a gray card interacted when dropping a lut on the footage. Check it out here: https://vimeo.com/157318638

Remember. c-log is meant to be graded, so as long as you have skin in a reasonable zone on the waveform, a decent colorist can pull it up or down a little to your taste. The biggest pitfall is exposing skin too dark (way below peaking at 50 IRE), at which point it will most likely be mush, no matter how good of a color grade you have.

Also, and this is big: don't use ISO's below 850 if possible. It seems banding can be more noticeable below 850. Haven't tested to confirm, but seems like it might be true. I've only had banding become a problem twice with c-log, and at least one of those I was definitely below 850.

Another good option is just eyeballing the waveform as much as possible, and keeping anything from clipping. I've found this can work, but you may end up underexposing skin way too much to accommodate crazy highlights. Sometimes that may work for certain shots though.

As to C-log vs. Wide Dr, I have no idea how much more info you're preserving by shooting c-log. It honestly doesn't seem that much, but I haven't tested. A good reason to use c-log though is to apply film emulation. Seems the best starting point for that. Another good use of c-log is for really nice black backgrounds. Maybe I'm not a great colorist, but I have a hard time making nice, deep blacks without shooting c-log and using a LUT. Here's a decent talking-head-on-black I shot with c-log: https://vimeo.com/user21442843/review/158445420/6f165139aa

One more suggestion. If you're on the mk1, I'd check out Paul Frederick's Wide PF profile, his tweaked version of Wide DR. I used to love using it on the mk 1. Color's aren't very "accurate," but footage looks great, especially in daylight, and lower ISO settings. Now that I'm mixing mk1's and mk 2's, I haven't been using it much lately: http://www.dvxuser.com/V6/showthread.php?315356-C100-Ninja-2-Nature-film-quot-Their-Last-Days-quot
 
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Ah, forgot one more thing: if you're shooting under those really strong LED party lights that are super saturated on one color channel, don't shoot c-log. Just don't. It already looks bad straight out of the camera in 8-bit. Trying to massage that at all will be even worse.
 
Thanks for the advice. I chickened out and didn't use C-Log on my shoot today, I felt that without shooting some tests, I didn't know what I was doing exactly so I used a profile that I knew would work and it did look good on the monitor at least. I had 8X8 Scrim Jim with a China Silk, a full and some other tools and two Aputure LS 1S for fill and rim so at least I had a little more comtrol over exposure. But the sunlight in LA was insane today, it was alternating very cloudy, then nuclear bright sun all day, I don't think I have ever rode iris as much as I had to today, the light levels and harsh direct sun versus soft cloudy sun were alternating at a ridiculous rate.
 
That's great advice, thanks for sharing Dan. It's good to have a system - I think I usually go for 50-60, but I'm not as religious about that as I wish. A lot of times when I'm running around, framing quick shots while things are happening all around, double checking IRE is not second nature to me yet. But thankfully C-log has enough play in the grade that a stop or two above or below won't be a disaster.

But we grade and edit all our own shoots. It might a different story if another editor got a hold of our footage and slapped us around.

And sorry about the chicken dance, couldn't help myself. :-)
 
I'm not one to argue with an ASC cinematographer, but I thought in C-Log the whole range was crushed down so that 90% in a regular profile (I've always heard IRE was for analogue systems and percent is the correct terminology for digital) = 60% in C-Log, or something like that (don't recall the exact numbers). And that the blacks get pushed way up so that your blacks are like 20-30%. I read a bunch of articles and posts before the first (and only, so far) time I've shot in C-Log. Maybe I'm way way off. The advice I got from a trusted colleague was literally just to eyeball it. . .look at the skin, and just see that it doesn't appear to dark or too bright/losing detail. There's also that simulation setting where the LCD will apply some kind of LUT so the footage has some contrast/color even in C-Log, and using that too judge. I don't know how one could judge a waveform accurately in a run'n'gun situation, especially being able to tell which part of the image is the skin tones (as opposed to a shirt or the background or anything else in the same area of the image horizontally as the skin).
 
That's exactly why I chickened out on using C-Log on my shoot yesterday, too many things going on. This was a no budget, logisitically challenging shoot with a crew of three doing what a ten person crew would normally be doing. We shot outdoor interviews. interview sitting on the ground as a character worked on their car, shot an interview with three Go Pros and the A camera in the car while a character was driving, shot at a meeting with a group of about 40 talent, roaming with handheld and a gimbal. It was too much to handle as it was, trying to think about shooting correct skin tones and proper IRE while running around like a maniac, shooting and rigging was nuts. Didn't even have a sound mixer. That's how spec projects are. I am going to try C-log but this was not the situation to do so. I need to shoot some exposure tests, check out Shane's advice about how to push skin tones up and I want to play with LUTs, no LUTS, etc. Too many variables to just jump in.
 
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Let me know what you discover. Like I said, I've only shot it the once. . .it was an outdoor music event, my stuff was all b-roll. I was a second cam op, DP insisted we shoot C-Log so I kinda had to. I did what my colleague said and mostly eyeballed, occasionally checking the waveform which I couldn't make heads or tails of in that situation. Checked the footage at home, more or less came out ok (I think I tried some LUTs out in FCP). That VF simulator mode helps quite a bit, even if it isn't super accurate.
 
I realize that I'm late to the party, but I recently tried out ntown's CinemaEX profile on my C100 MK I. And WOW. From the site:

The infamous S-Type Gamma curve from Canon which is pretty popular now. This is a tweaked version which regeains the corrects video levels to be within IRE 100 and can be graded greatly while taking advantage of more brightness steps due to the lower black and white levels and therefore not falling appart too fast and reduced banding effects, which are the biggest problem on low-contrast, black-rised imagery, especially when recorded at 8-bit!
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I was really impressed with the results. It's like a whole new camera. With NeatVideo, I'm pretty confident that I can get usable results shooting all the way up to ISO 12800. This is a HUGE jump from what I've experienced with WideDR, which has been my go-to for the past couple of years. With that profile, I rarely shot anything above ISO 1600. Good color, decent DR, but... pretty limiting.

Here's the Cinema5D article that opened my eyes: https://www.cinema5d.com/canon-c100c300-custom-picture-profile-noise-comparison/
 
From my understanding, the CinemaEX profile shifts the curve so that 110%IRE is recorded at 100%IRE and the black level is crushed down to 0%. I somewhat understand crushing the black level down to 0%. Whenever I used WideDR, I had my own profile that dropped the black pedestal by about 8 since I found that extra stop in the blacks too noisy and I didn't want to fool myself into thinking the extra visible shadow detail was actually useable. But it seems to me that if you drop your whites below clipping, you are just throwing away useable data.
 
Interesting point. I have noticed that it clips highlights sooner than WideDR. In fact, I had to go back to WideDR for a few shots where the sky was blowing out on a shoot today. I'll have to give your approach a try. That's just [ Gamma: Wide DR ] and then [ Black > Master Pedestal: -8 ], right?
 
I also added some saturation and increased noise reduction to 2. It is really the noise reduction that seems to be the downfall of Wide DR. As far as I can tell, CLog actually has some noise reduction built in to the processing, but Wide DR acts like a regular picture profile with the blacks pulled up and no noise reduction.
 
Thanks. I will give this a try. WideDR that doesn't turn into a mass of chroma noise in the shadows before even grading it would be a great tool.
 
QuickHitRecord said:
Thanks. I will give this a try. WideDR that doesn't turn into a mass of chroma noise in the shadows before even grading it would be a great tool.
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On C100's, especially the mk1, I have great luck switching to a CINE 1-based profile for high ISO shooting. Not as much DR, but looks very nice to my eyes. Reset the profile to neutral, and just change the gamma and color matrix to CINE 1 or CINE 2.

Though I find WIDE DR pretty lovely except when pushing the ISO. Are you have trouble with WIDE DR across the board?
 
None, that's it. (Besides turnaround time, if any...could be ready to go right away.)

Noise is always debatable based on environment/exposure/user preference or tolerance.
 
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