Video: Upgraded Canon Log2 and New Canon Log3

[Barry Goyette]

Jon Carr and Canon released a video today showing the new "upgraded" Canon Log2 and Log3 in the newest version firmware.

C-Log2 looks much improved in it's shadow noise. Log3 seems like a modest upgrade to the original C-Log, with less saturation in near clipped highlights and perhaps a little cleaner color in the shadow. New firmware should be released tomorrow.

C300 Mark II Firmware Update: Side-by-Side 4K Comparisons of Canon Log, Canon Log 2 and Canon Log 3 - YouTube

[Mark Dobson]

Thanks for that Barry.

Having fried my c300 doing a firmware upgrade a year ago I might pluck up courage and install the new C300mk2 Firmware although I'm pretty happy with Canon Log.

[Barry Goyette]

The new firmware v.1.0.4.1 is now available via the CanonUSA website.

https://www.usa.canon.com/internet/p...B0AMD0F1Q42K25

(I think I'm going to set up a DR/Color test in the studio to compare before and after. While the noise reduction in the shadows of cLog2 looks pretty good, canon was generally proud of how much detail they were holding in the deepest shadows with CLog2, so I'm curious how much, if any, of that detail we'll be losing, plus any color changes that might have happened in the interim.)

[Jon Roemer]

Matt Porwoll has a pretty extensive look at C-log 3: Matt Porwoll | Cinematography » Canon C300 MKII: First Look at the new Canon Log 3 Gamma

[Barry Goyette]

I upgraded to the new firmware, shooting a before and after test in the studio with my homemade ghetto xyla chart.

Not much in the way of surprises. Clog2 sees a modest reduction in noise at 800 iso, and is very usable at up to 3200 I think. Clog3 adds a stop of DR in the highlights, and the color in the highlights looks cleaner. The net effect for someone shooting Clog3 "to the right" is a much more open mid and shadow range, greater tone separation below 20 IRE, compared to the original Clog, something that I always was yearning for from that gamma. This could be my new favorite setting, although CLog2 is certainly much more useful than it was before.

As far as the noise reduction in Clog2, there doesn't seem to be much penalty. I see no loss in details. There is a drop in luma noise, which slightly unmasks the chroma noise that was already there. The highlight smearing is reduced, but not eliminated. It's still visible in the darkest chip of the chart, but has disappeared further up the scale, which is exactly what you'd hope for.

I'd say, good job Canon. But I always say that :-)

[Dan Parkes]

Thanks Barry for the review, sounds good to me.

I'm also looking forward to checking this particular 'new' feature: "Enables magnification to be used even during recording." Finally! Glad that Canon is listening to its customers. I thought it might a technical limitation, but apparently not. Now for some slow mo frame rates in 4K and we'll all be happy.....

As I have two Canon C300 Mk2s, I am planning on installing this firmware only on one for now, to do a comparison, especially of Clog2.

[Barry Goyette]

Originally Posted by Dan Parkes

Thanks Barry for the review, sounds good to me.

As I have two Canon C300 Mk2s, I am planning on installing this firmware only on one for now, to do a comparison, especially of Clog2.

Great idea. I forgot to run an ISO range pass before I did the upgrade. While I can say with some surety that things look better in CLOG2 at higher ISO's up to about 6400, and that 3200 looks reasonably clean, I don't have the before/after comparison to prove it. What I can say for sure is that both the CLog2 and CLog3 upgrades have made this camera more useful than before, and I really didn't have much to complain about before. Haven't tried the magnify while recording, but I'd imagine it's pretty much as advertised.

[Gary Huff]

Canon also fixed the issue where switching frame rates (i.e. 23.98 and 29.97) would have the camera reset the resolution. So if I had been shooting 29.97 1080 at one job and I switched to 23.98 for another, the camera previously reset the resolution to UHD. Now it stays at 1080.

I have a list of issues Canon still needs to address, such as S&Q toggling via a body button, a fixed shutter angle (that drives me absolutely bonkers), DPAF functionality in VFR modes 60fps and under, Face Detect+Follow DPAF (so when the talent turns their head and Face Detect switches into DPAF mode, the targeting reticle is now where Face Detect was last used instead of where you last moved the DPAF target box), and Normal Recording (crop) mode to eke out just a bit more zoom for telephoto moments when you aren't using slow motion.

As for 4Kp60, if that happens, it will be by the end of the year, and if you don't see it by year's end, I don't think it will ever happen. Also, keep in mind that the ability to do 4Kp60 means the bandwidth is there to do 1080/2K in 120 without the crop. So It seems highly unlikely in my opinion.

[Barry Goyette]

Yeah the frame rate reset thing has gotten me more than once, so happy to see it fixed.

As for the 4kp60 one, when you look through the image pipeline white paper, the image is processed at this rate until it is downsampled and compressed. So on the processing side, the bandwidth is there The bottleneck seems to be in the compression stage, which, to me, sounds like a typical Canon move. They feel 4kp60 needs more than 515 mbps or whatever the max is for the codec currently.

And then, of course there is that camera they are supposed to unveil at IBC.

[Gary Huff]

Originally Posted by Barry Goyette

They feel 4kp60 needs more than 515 mbps or whatever the max is for the codec currently.

I've seen 600Mbps, not sure what that is in practice though. I would assume Canon is thinking 800Mbps minimum, possibly even 1Gbps? I don't know that I mind topping it out at 800Mbps for 60p, given how efficient XF AVC is.

However, it's not simply a codec thing because, again, if the bandwidth is there on the front end, then there's no need for a crop mode. If you get 4Kp60 working on this camera then crop mode is no longer needed. And the bitrate in crop mode is the same as the bitrate normally, so it's the upfront processing that makes crop mode necessary, which means it's the bandwidth from the sensor to the encoder (because otherwise the sensor could be fully scanned at 120fps for 1080 120 instead of cutting out a 1080 piece of it).

[Barry Goyette]

So...again this info is from the C300 II white papers...the maximum bit rate in XF-AVC for the camera is 550 in 120 frame HD or 2k mode (vs 410 for 4kp30).

When you look at section 6.0 of the image performance enhancements white paper, it gives a workflow for the 1080p60 YUV 4:2:2 (figure 3). If you read the whole document, it becomes clear that the YUV workflow is essentially processing the image at 4kp60 (balloon showing RGB 8mpix frames) followed by downsampling to HD or 2k. The pipeline is identical to the one used when it's processing 4kp30, the only difference is in the 4k mode it's doing it at 30 frames and then skips the downsampling step prior to compression. (figure 5). So the camera is fully capable of processing the image all the way to the point of compression at 4kp60 in 10bit 4:2:2 YUV. It really seems like a compression (encoding) or "write-to card" issue, which, I think was why initially Mitch at Convergent Designs stated that they should be able to record 4kp60 to the odyssey recorders (until he got his hand slapped by Canon and retracted the statement).

I really had hoped that we'd get an upgrade for this...but given that they didn't do it with this most recent firmware bump, I think we're looking at a feature that will differentiate the c500 replacement.

[Gary Huff]

I think that's fine and dandy, but then that still does not explain why there is a crop mode for 1080/2K 120 at 10-bit 422. If what you say is true, then why is there a crop mode at all? The bandwidth is the same, and picking between downsampling and a crop is something done right at the front of the image processing chain.

[Barry Goyette]

There's a section in that white paper that talks about the 120 fps mode. I think it's more than "the same" bandwidth.

---"the data rate of the video components emanating from the image sensor system must be constrained so that the processing and recording can retain a high integrity."

If we look at how it's processing the 2kp60 image in full frame, it's processing it at 4kp60 and then downsampling to 2k/HD. Given this scheme, full frame, 120fps 2K/HD would need to be processed at 4kp120 and then down sampled. So the actual processing bandwidth would need to double, or they would need to debayer in a completely different way for this.

Now sure...sony's done it, although their process seems to add about the same amount of aliasing as canon's does....I don't think either of them look that great. I believe the C500 dropped some vertical resolution to get it's higher frame rates.

...but I'll bet that new camera coming out next month....

[Gary Huff]

Originally Posted by Barry Goyette

So...again this info is from the C300 II white papers...the maximum bit rate in XF-AVC for the camera is 550 in 120 frame HD or 2k mode (vs 410 for 4kp30).

Not sure where you got that. The only option you can select when you record 120 VFR is 160Mbps XF AVC 10-bit 422. I thought perhaps you were talking about the image processing bandwidth, but you do mention XF AVC. Also, it should be pointed out, that 12-bit 444 1080/2K are the same bandwidth in XF AVC and cannot shoot over 30p.

Originally Posted by Barry Goyette

If we look at how it's processing the 2kp60 image in full frame, it's processing it at 4kp60 and then downsampling to 2k/HD. Given this scheme, full frame, 120fps 2K/HD would need to be processed at 4kp120 and then down sampled. So the actual processing bandwidth would need to double, or they would need to debayer in a completely different way for this.

I see what you are saying and I went back to the whitepaper and something stuck out at me, how the camera was always sending out a 4K raw (i.e. uncompressed in practice) signal whenever Canon Log 2/3 was selected in the preset. So I tested it with my Atomos Shogun and, true enough, it is sending out 4Kp30 even when the internal format is 1080p60. That is very interesting I think.

Now sure...sony's done it, although their process seems to add about the same amount of aliasing as canon's does....I don't think either of them look that great.

Agreed. I think Canon's version eliminates more of the artifacting at the expense of DR and detail. I haven't seen anything yet that is Bloom's horrendous shot of the child from The Wonder List where his forehead has a heavy moiré effect going on (I have never once seen moiré on skin except in that instance), and the 120fps mode is definitely softer (though not as soft as some of those pre-release clips clearly shot at a 360 degree shutter). I have used 120fps about three times in the year that I've owned the camera, and far more at 48 and 60.

I believe the C500 dropped some vertical resolution to get it's higher frame rates.

The C500 output 4K "half raw", which dropped out every other line of vertical resolution. 2160 divided by 2 is 1080. So it was an effective 3840 (or 4096) x 1080 image. I would be okay with that only for clients who want 4K and slow motion and don't know how to do a proper upscale. I don't have any of those at the current time. However, for other jobs, I'd just as soon shoot 1080/2K and upscale myself with proper software and the heavier processing power of my workstation.

[Barry Goyette]

Originally Posted by Gary Huff

Not sure where you got that. The only option you can select when you record 120 VFR is 160Mbps XF AVC 10-bit 422.

These charts (from the extended recording options white paper) have appeared in several iterations since the camera was announced. The 550mb/s rate never made sense to me (you would think it would be 320 or less).I don't really use this mode, so I've never checked to see what was actually being recorded.

But...that's where I got it from...