c300 Mark II CLog2 Nitty Gritty

[Barry Goyette]

Spent a good chunk of yesterday in my studio with a 15-16 stop test scene cycling though the myriad of gamma and color space options available on the new camera. I had two goals. One was to compare Clog on the original c300, which is what I'm used to, with Clog on this camera. The second goal was to get a handle on CLog2, to see what it's doing, and to see how much flexibility it gives, but most importantly to learn its quirks (and it has a few) so I don't make any huge mistakes on the first job or two with the camera.

Both tests are ongoing, and given my work schedule the next few weeks, I'm not sure whether I can do a detailed post or not. So, I thought given that I'm up early today, I'd take a few minutes to mention a some of the takeaways from what I've seen so far.

CLog -- New versus Old
This test needs a lot more work, but right off the bat I'm seeing lower noise overall with the new camera...but this comes with a caveat. With the old Clog we saw a relatively uniform noise profile across the tonal range of a given scene -- almost like it was added in (it was :-). The new camera exhibits about the same noise as the old camera below 25 ire and generally… shockingly clean results above that point. even at higher ISO’s. A slightly lower contrast scene shot "to the right" at ISO 20,000 saw almost no noise except in the deepest shadows that would normally get crushed in the grade. Phenomenal. Overall, there seemed to be more color range and saturation in the lower end of the spectrum on the new camera.

CLog 2 - All New
Canon is really stretching the limits of both it's sensor and the 4:2:2 flavor of it's codec (my cards arrived but no reader, so I'm currently limited to capturing pro-res on the Atomos), it's really important to get a couple of things right when exposing for clog2.

During the lead-up period to the C300 Mk II release, there were a number of early user videos, many of which, in my terribly arrogant opinion, had poor, or certainly challenged color. Sometimes this could be put off to the grade, but something told me there was something going on, on the camera side, that was causing some of these results. Many of the videos had a reddish tinge, but one video in particular had flummoxed me, shots of a yoga girl in Japan, as it appeared to have strange crossovers in much of the footage...greenish shadows with red mid-tones. At the time I put it off to inexperienced grading, but then on my first shots here in a "very" neutral set, I was seeing exactly same thing. Red overall with a sudden green shift at about 5 ire.
This freaked me out at first. But it turned out to be two things, both unsurprising, but still worth mentioning.

White Balance
It can be difficult to judge white balance when viewing Log Gammas, and Clog 2 is an order or two more difficult in this respect than the original Clog. (I wasn’t using a monitor LUT as I wanted to see what the native log tones were doing). The scene I set up was lit predominantly with a single Area48 LED with the daylight panel installed. These lights are among the most accurate LED on the market with a TLCI hovering between 95-98. With my C300, I've come to prefer a manual Kelvin setting of 5600 with these lights, and this is how I set the new camera at first. After that I cycled through the new AWB setting (it registered 5300K), the daylight preset, and a range of Kelvin levels. I also applied a manual WB which surprisingly, settled on a level of 4300 for these lights. From my experience with the C300, I've learned to be skeptical with led's and manual white balance and the fact that the AWB and manual WB produced startlingly different results combined with typically good c300 results at 5600K, I shot most of the test using the manually entered 5600k. Once I got the footage into my system though, I was in for a rude surprise: the daylight preset, AWB, and 5600 Kelvin settings were all quite red compared to the C300 and every other camera I own. The manual WB on the other hand was in fact quite accurate . I haven’t so much as taken this thing out to shoot a second of actual daylight, but I think I understand now why I've seen so much red in many of the videos posted so far.

ABB -- Auto Black Balance
With my C300 I mostly used this feature to clean up (or pre-empt) any hot pixels that occasionally occurred. With Clog2, it turns out that this is an essential procedure in terms of color balance, and one that requires perhaps more than a "do it and forget it" attitude. After my first round of shots produced the funny red with green shadows (the green shadow effect isn't subtle and is visible on the camera EVF and LCD even while in Clog2), I ran an ABB with my favored, lazy, lens cap technique (this is the big, coffee can lid lens cap that comes with the cinema lenses -- which has always worked fine on the C300) and watched on my atomos as it cycled through the test. When it finished I noticed now that the shadows were now red instead of green. Several other cycles of ABB using this technique produced similar results. At that point I decided to do what the camera says (use a body cap) and wah-lah...finally I'm seeing a neutral shadow. Certainly the argument goes that you should always ABB, I just think its worth noting that the effects of “not” black balancing when using CLog2 will be more noticeable than other gammas on other Cinema Eos cameras.... and hang on to your body cap.

ISO, Noise, and CLog2
This is a broad topic and one that’s been covered in a lot of places from Cinema5d to CML. I don’t intend to challenge any of what’s been printed thus far. I had a couple of specific goals in mind as I ran through the various gamma settings and ISOs. First up, like all Cineon type curves, CLog2 shows quite a bit of noise in the shadows compared to other gammas, even at base (800) iso. One could argue that the noise in Clog 2 is a bit more than other cameras by other manufacturers, and is more “electronic” than what we’re used to with canon’s 8 bit cameras, and I’d agree with that, adding that in minimizing noise reduction with this camera, Clog2’s shadows seem to harbor more detail than many of the other cameras with similar curves. Also, when properly black balanced, this noise is mostly luma noise, making it much easier to grade than some cameras I’ve seen.

Taking it higher.
One of the interesting things I noticed was that in high ISO situations, with the same exposure, sometimes there’s benefit to shooting at a Higher ISO than you need, as long as you’re not clipping anything. Canon is doing some pre-processing gain on the sensor and in my tests, I found that I could use ISO to “shoot to the right” and achieve a result that was a bit cleaner at a given exposure level (f-stop). I also did a shot at 51,200 and cleaned it up with Neat Video and it really looks stunning. Virtually no detail loss and plenty of dynamic range.

Below the belt - The Low End.
Base ISO on this camera is supposed to hit a happy medium of shadow noise and dynamic range. But some might find that the shadow noise at this setting bugs them, (and require a certain amount of hand-holding when delivering ungraded footage to a client which I occasionally do). The general rule here is to rate at 800 but to overexpose by a stop or more, and this works, but in high dynamic range scenes, one may not want to give up that stop or more of headroom to control noise in the shadows. I experimented with lowering the ISO down as far as 200 (the native ISO of the sensor is actually 100), and I was quite surprised by what happened. As you lower the ISO below 800, the camera starts lowering the maximum IRE level accordingly. Essentially whatever maximum exposure you’d use at ISO 800 is the same at ISO 500…400, 320, and 200…they all peak at the same Fstop. Whats interesting though as you lower the ISO below 800, is the overall dynamic range stays the same, the shadows compress a little and the noise characteristic in shadows changes dramatically (it gets really pretty). Essentially you get a look that is similar to the original Clog, but with a full 15 stops of range and very clean shadows, the caveat is that more of that range is below 18% grey than base iso (similar to Clog but with more highlight range). Interestingly, when I graded ISO 800 and 200 samples back to “normal”, meaning I was stretching the mid tones up on the 200 clip and pulling the shadows down on the 800 clip…the result was still a significantly cleaner shadow on the 200 clip. Again..we’re talking about the same exposure here. I have to say I really liked the look of the lower ISO’s on this camera and I think for any low key situation or anything with “lower than 15 stops DR), I’ll be choosing to shoot at lower ISO rather than the recommended “shoot 800 and meter at 400” method.

I’m thinking this approach might be a bit controversial, (and I haven’t tested this in the real world or with real skin tones) so I’m interested in hearing what other users have to say.

Much more to come on this topic.

[Jim Martin]

Brilliant Barry!

[Sabyasachi Patra]

Barry,
Great to see your observations.

I was about to ask you for a comparison of high ISOs between C300 and C300 II. I would love to see the ISO 51200 sample. If indeed it can be used, albeit with some neat video, then it would be helpful. Till what ISO one can shoot without neat-video?

The 51200 sample is C-log or C-log 2?

I am used to manual white balancing with my C300 and also the body cap method for AWB. So no problem in that front.

Thanks a ton. Look forward to more of your observations.

Cheers,
Sabyasachi

[Barry Goyette]

Hi Sabyasachi,

I shot the 51,200 sample in CLog2. I think in CLog, 20000 is still usable without denoising as long as you can keep most of the tones somewhat to the right. If you're fighting for light at this ISO, or if you have a heavy scene, then you'll need to consider a denoising pass.

[Barry Goyette]

Originally Posted by Sabyasachi Patra

I was about to ask you for a comparison of high ISOs between C300 and C300 II.

This was a quick side by side I did the first night I had the camera. Halogen tungsten lighting. ISO 20,000 at 200%. Mark II on the left. C300 on the right. Canon Log. (I'm not sure the detail difference in the isn't focus or even a slight lighting change). Noise is slightly more present in the older camera. (FWIW...the CLog2 at 20k is event quieter, albeit shot at lower fstop. The noise is finer and is mostly luma noise. (not happy with the color on it so I'd rather not post an image yet).

[Barry Goyette]

A couple of updates. Used the new camera on it's first proper shoot a couple of days ago. Kind-of a crazy one man shoot involving two cameras, substantial lighting, an ad-hoc choir of 7-11 year olds and a program director turned Martha Stewart client.

White Balance -- I can confirm that my C300MkII consistently white balances at numbers 1000ºK warmer than it should under most lighting sources. Known Daylight LED are reading 4400k. Daylite metal halide practicals that read 4600 on the C300 read 3600 on the new camera. Actual daylight reads at 4200-4600. For those of you looking to match C100/c300 footage with the mark II, I don't see many problems. Once balanced the two cameras looked largely identical (Canon Log, Rec 709, Original Canon Log matrix), although the new camera's image is a notch or two cleaner.

Completely...or partially off topic. On my way home, I decided to meet up with my girlfriend who was Tango dancing at our neighborhood coffee bar/gallery. Argentine Tango Dancers love to dance in the dark. And they had turned off all the lights of the cafe and strung a single low wattage rope light on the floor along the perimeter of the room. That's when I decided to do something stupid. I ran out to the car and grabbed the camera, which was still rigged up with the handle, monitor unit and an 85mm Cinema lens. About 11 pounds I'd guess. I then put the thing in 120 frame crop mode for the first time and dialed it up to 12,800 iso and proceeded to attempt to handhold a few shots....all the while telling myself...that this shouldn't be possible...that shooting in a room with almost no light using a crop sensor, a long lens and a 120th sec shutter speed (the camera defaults to this, and I think it's why some of the footage we've seen doesn't look sharp, it should default to 240th sec.) -- this situation I found myself was inherently wrong..yet...somehow...it worked... and it looked great. Sure there was some noise...but really nothing to be worried about. The moody lighting combined with a bit of grain reminded me of the wedding scenes in the Godfather, pretty much how it should look. (There was a dedicated sony shooter in the room, and she walked away shaking her head at what she was seeing.). Impressed?....yes.

The next day I decided to try the 120 frame mode in the daylight. I don't really see any sharpness issues like some of the videos we've seen posted. It's not the same as the full sensor HD (I'd say the look is somewhere between the 5dIII and the C300)...but I wouldn't have any problems cutting 120 frame shots into any project that I work on.

[Noa Put]

There was a dedicated sony shooter in the room, and she walked away shaking her head at what she was seeing.). Impressed?....yes.

Are you sure she was not holding a a7sII shooting the exact same scene at 204.000 iso? She might have been shaking her head for another reason. :)

[Gary Huff]

Originally Posted by Barry Goyette

The next day I decided to try the 120 frame mode in the daylight. I don't really see any sharpness issues like some of the videos we've seen posted. It's not the same as the full sensor HD (I'd say the look is somewhere between the 5dIII and the C300)...but I wouldn't have any problems cutting 120 frame shots into any project that I work on.

Apparently Canon has this "feature" in which the shutter angle will change for you to compensate for exposure differences between frame rates. I believe the difference with the 120fps footage is that some shooters are shooting at 360 degrees and others, like myself, are shooting at 180 degrees (i.e. properly).

I took the camera out over the weekend and was very impressed with the quality of the 120fps footage I shot. All of which I shot with a 180 degree shutter (after the camera reset itself to 360 degrees when I made the frame rate change).

Canon has a history of trying to do things that make their images look like shit when put the hands of somewhat unskilled operators (i.e. the PF24 b.s. in the C100 that made people deinterlace instead of properly removing 3:2 pulldown that made some videos look ugly and soft).

[Barry Goyette]

Originally Posted by Noa Put

Are you sure she was not holding a a7sII shooting the exact same scene at 204.000 iso? She might have been shaking her head for another reason. :)

No...she uses a real camera, like me..:-)

From what I could tell, and I don't have an A7sII, but looking at the 120fps cropped low light footage Dan Chung posted awhile back, the C300 looks better in crop mode at 12,800 than the A7sII at 6400. I'll leave that 204,000 stuff to you, Noa.

[Noa Put]

I was just pulling your leg but seriously, it's never a good idea to take the camera with you when you have a date with your girlfriend :)

[Jon Fairhurst]

Originally Posted by Gary Huff

...I believe the difference with the 120fps footage is that some shooters are shooting at 360 degrees and others, like myself, are shooting at 180 degrees (i.e. properly)....

I think the "proper" shutter angle depends on the use case. For high speed shooting that will be slowed to 24 fps for a film look, 180 degrees would be correct. For high frame rate playback at 120 fps for sports or documentaries, 360 would be proper.

The reason is that 180 is standard for a film-like experience, but 360 at 120 fps playback gives a seamless experience without an unnatural strobe effect. When the bat swings or the helicopter blades turn, you will see a continuous blur, rather than discrete "samples" of the motion. I've recently been studying 120 fps playback and this gives the most artifact-free experience.

Canon engineers might have been considering the sports case above the narrative case. It would be nice to have a programmable default that one could set based on one's output target.

[Barry Goyette]

Originally Posted by Noa Put

I was just pulling your leg but seriously, it's never a good idea to take the camera with you when you have a date with your girlfriend :)

Yeah...I know...that was me pulling your's back. Lucky for me, it wasn't a date...she was dancing (with other guys...mostly 60 year old tango nerds) and I was eating and watching. And I've never known a dancer who didn't like the camera pointed in her direction (as long as she's dancing)...so I did all right. :-)

[Sabyasachi Patra]

Thanks Barry!

You are confirming my suspicion that once my current project is over, Canon will get my cheque.

Also, any idea if the C300 Mark II LCD can be used in the original C300?

[Barry Goyette]

No. Canon rewired the connections so that one carries audio and the other video... So if a cable goes down, you can still get video over a single cable. The older LCD requires both cables to work. I think the connector is different too.