C100 MKii Newbie C log question

[Paul Celeste]

Hi all, First post.

I just received my C100 mkii coming from the dslr world. Looking forward to shooting and grading in C log.

Is shooting C log the best for both grading and/or applying Luts? If so, does anyone have any suggestions for luts I should be considering. Thanks

P

[Noa Put]

Shooting in log is best when you shoot a scene with a wide dynamic range, if that is not the case then log is not always the best choice.

[Gary Huff]

To answer: if by "grading and/or applying LUTS" you mean that you will primarily be just applying a Clog->Rec.709 LUT then I ask: what's the point? If you just shoot WideDR, you'll get most of the benefit without being required to add a plugin effect on every shot.

Depending on your processing, applying a LUT can also obliterate all the detail held in the highlights/shadows and thus you don't gain anything. Log footage is best graded straight up in actual color software (Resolve, Speedgrade, etc), with a LUT being used to either move the space from Clog to, say, Cineon, or some specialty grade you are trying to accomplish (i.e. ImpulZ). I see too much user of a basic Rec.709 LUT, then a tweak of the contrast and saturation and then calling it "grading", when you could have shot WideDR and done the same thing without spending the time on the extra step.

There are times when I use Clog, Clog2, or Rec.709 internally, and it depends on the project and what I'm looking to accomplish. Lots of outdoor stuff with alternating shade/sunny areas? A Log gamma will help maintain the detail so that you don't look blown out like everyone else (provided you grade it properly, because, again, simply applying the LUT can obliterate all of that retained detail). Going to be mostly indoors with a small window far in the background? Shoot Rec.709 and light the interior so that the window retains detail within that lower DR.

[Paul Celeste]

Thanks guys, this is the information I'm looking for. It's an education. I'll get there.

[Terence Morris]

Originally Posted by Gary Huff

To answer: if by "grading and/or applying LUTS" you mean that you will primarily be just applying a Clog->Rec.709 LUT then I ask: what's the point? If you just shoot WideDR, you'll get most of the benefit without being required to add a plugin effect on every shot. DR.

Sorry, I know this is an older post, but it's very close to my question:

Isn't the reason some shooters use Clog is not just to maximise dynamic range, but to begin with a much flatter profile that most LUTs are designed to then reshape? I'm wanting to experiment with my new C100 MkII using Clog for film emulation or Arri-type looks. Most of the LUTs ask for Clog as the starting point. Am I wasting my time? Should I just use Wide DR (which I love BTW) and just tweak it with say Colorista to my preference?

[Wacharapong Chiowanich]

I'm a frequent user of the C100xx and agree with Gary that on this particular camera at least the Wide DR mode is almost always the best starting point if you can't control the lighting. Log gamma, by design, always sacrifices detail and gradation in the mid tones to achieve the wider recordable detail and gradation in the highlights and shadows so you essentially lose some when you gain some especially in all the compressed formats.

If for any reason such as the inability to block out some light from the windows or light up the room to raise the illumunation level close to that from the windows for instance, then C-log might work for you but again it won't be anything like well-lit or properly angled shots.

I use Resolve to deal with the rare instances when I have to use C-log and sometimes only use the level control on FCPX Color Board to get the footage to look right on the Rec.709 monitor.

[Gary Huff]

Originally Posted by Terence Morris

Isn't the reason some shooters use Clog is not just to maximise dynamic range, but to begin with a much flatter profile that most LUTs are designed to then reshape?

Log gamma is entirely about the DR. The problem is that you will be exporting to Rec.709 for YouTube/Facebook/Wistia/etc. and you'll lose all those additional stops at that point anyway. Now, if you like to go back to old projects and "remaster" them, then when these online streaming sites begin supporting Rec.2020/HDR10, it would be good if you shot in Log gamma. If you don't foresee yourself doing that very often, then you're giving yourself more time in post for little benefit. I am experienced enough to decide what I want to lose in the highlights right there at the moment. Shooting in Log makes you take the same decision in post later on.

I'm wanting to experiment with my new C100 MkII using Clog for film emulation or Arri-type looks. Most of the LUTs ask for Clog as the starting point. Am I wasting my time? Should I just use Wide DR (which I love BTW) and just tweak it with say Colorista to my preference?

As far as the flatter color profile, they are often synonymous with log, because you get a "cinema" color space with it, but again, it doesn't matter. FilmConvert, ImpulZ, and Red Giant Film all can start with the normal color space and don't require you to shoot in the desaturated Cinema one. In fact, less tweaking is better when it comes to highly compressed codecs, such as the C100s AVCHD. Which was why, when I did shoot log, it was always out to an Atomos/Convergent Design/Videodevices recorder in ProRes HQ.

Check out this video (I didn't shoot it):

BMW Unscripted

Can you guess which camera that was shot on?

Originally Posted by Wacharapong Chiowanich

I'm a frequent user of the C100xx and agree with Gary that on this particular camera at least the Wide DR mode is almost always the best starting point if you can't control the lighting.

Well, I would say you use WideDR when you can control the lighting. I have a big shoot I am doing right now where everything is with the C300 Mark II's version of WideDR, and there are a lot of windows. I have control inside, but not out, so I light mainly for the talent and then to get just enough detail outside the windows under changing lighting conditions that it looks nice. Log would be if the lighting differences were just too extreme, but again, I still have to lose it in post anyway. So a blown out window shot in Log that retains detail will be blown out after correcting for the subject in Rec.709.

[Dan Brockett]

A lot of it depends on the camera. The C100 shoots 8 bit so it's ability to record LOG in a usable fashion is limited. If you shoot with a camera like the C300 MKII, especially in 12-bit, LOG can be a very effective tool. For the C100, IMHO, I agree, WDR is the best for almost all situations other than if you are under exposed, then it is grainier than some other picture profiles you could use. C100 into a Blade recorder, you can use Log but not sure if the end result is better or even as good as WDR in a correctly exposed scene.

[Gary Huff]

Originally Posted by Dan Brockett

A lot of it depends on the camera. The C100 shoots 8 bit so it's ability to record LOG in a usable fashion is limited.

Clog was built for 8-bit.

[Dan Brockett]

Originally Posted by Gary Huff

Clog was built for 8-bit.

I know, I am just speaking from results I have seen. It's just like the HDR upgrade on my Ninja Blade. On a 450 or 500 nit monitor, it's more of a nice wish when compared to the higher end screens that have 1500 nits brightness with HDR.

[Terence Morris]

I can always rely on some substantive feedback from the dv.info folk! Thanks, everyone. Work kept me from responding earlier, not tardiness.

It makes perfect sense, now I see it, losing tonal steps in the mid-tones, especially given we have only an 8-bit image to begin with. And I am one obsessed with skin tones. It is easy for the less enlightened, such as myself, to get swayed by flat out assertions, even by ostensibly pro videographers (top of my head, e.g., Dan McCombe) that to get the "best" from the C100, you should pretty much always default to Clog and then LUT the footage in post, as if this were a raw digital image (which of course it isn't).

I will continue to use Wide DR for most projects, but on this reading, I should probably use the "normal" setting, i.e., no picture profile rather than Wide DR, for the occasional green screen stuff I have been doing for a corporate friend (together with a Ninja Blade / HQ ProRes). And I'm guessing that without setting a picture profile the C100 puts out some variant of Rec 709? The Canon manual is oddly reticent about stating that explicitly, but maybe I missed the small print.

-Terence

[Gary Huff]

If you were ETTRing your image, then that's why you were not getting good skin tones.

[Terence Morris]

I actually haven't had ANY problems with skin tones from the C100 on Wide DR - they look gorgeous so far. This was merely a question about the utility of Clog, which so far I haven't tried out. Sorry - I have no idea what ETTRing is.

[Gary Huff]

ETTR = expose to the right. This means exposing your image at a higher IRE value than the Clog spec calls for. This is to crush the blacks and hide noise. It will do that but at the expense of your image, notably skin tone. If you want good skin tone in Clog, you have to expose the skin at the proper IRE value, which is about 50IRE.

[Terence Morris]

Thanks for the extra info, Gary. Makes sense whenever the day comes that I use Clog. I've always been a duffer for acronyms!