AI algorithms for debinning

[Jonneh]

There is no 3584x1730 crop mode in 5D3

It might be slightly modified in the latest build (don't have my camera with me to check), but it was there in Danne's September 2020 build (see post 619 here: https://www.magiclantern.fm/forum/index.php?topic=23041.600). Either way, I take your point that there seem to be different sensor readout limits in different modes, which is very interesting (I'm assuming you have a way of know that the limiting factor in each case is indeed the readout speed, and not something else).

we can already do 3072x1920 @ 24 FPS in 1:1 mode, but we can't achieve 1920x3072 @ 24 FPS in 1x3 Binning (anamorphic) mode on 5D3, even if it the same read out speed

Weird! If the binning is done at the analogue level, could this affect the readout speed?

What I'm still in the dark about is where the 135 MB/s card-spanning write-speed limit comes from. Is this another mystery?

[theBilalFakhouri]

@Jonneh

Oh sorry, you are correct . . yes there is 3584x1730 @ 24 FPS in latest Danne build . .

Weird! If the binning is done at the analogue level, could this affect the readout speed?

Not the Binning modes exactly, but the FPS timers:

Timer A is directly related to horizontal resolution. Timer B is directly related to vertical resolution. They are not the same, but if you increase one, you may also have to increase the FPS timers.

from:
https://www.magiclantern.fm/forum/index.php?topic=19300.msg197098#msg197098

In order to increase vertical resolution you need to increase FPS Timer B (increasing FPS Timer B decreases FPS) , I could do 1920x3072 1x3 @ ~20 FPS, but not in 24 FPS, in this case we need to lower FPS Timer B to get 24 FPS in 1920x3072 in 1x3 mode, but doing that broke the image and might freeze the camera . . it's weird because we didn't hit read out speed limit yet . . there are other *head* timers are related to FPS Timers, tweaking it are not enough . . maybe there are other registers needed to tweak . .

BTW there is no problem like that on 700D . .

What I'm still in the dark about is where the 135 MB/s card-spanning write-speed limit comes from. Is this another mystery?

In LiveView the camera uses more memory cycles resulting in lower write speeds, lowering framerate from "FPS override" helps . .

In my previous tests, maximum write speed with card spanning in PLAY mode is ~155 MB/s (5D3.123) using 160 MHz, 192 MHz and 240 MHz overclock presets, in LiveView the write speed decreases a bit due to more memory cycles are used which became ~135 MB/s write speed when the framerate @ 24 FPS . .

~155 MB/s write speed limit in PLAY mode is coming from the memory (RAM), so I think it's a memory speed limit here . . bypassing this memory speed limit somehow may increase card-spanning write speed in theory . .

[mlrocks]

I just did some tests on 650D in the mode of anamorphic UHD AR 2.4 14 bit /14 bit lossless 24 fps, for a complex scene, the data flow is calculated by ML to be around 55 MB/s. If 5D3 can bypass the fps speed limit control in high fps mode, with a current maximal writing speed of 135 MB/s, on 5D3, 60 fps slow motion of anamorphic UHD AR 2.4 14 bit /14 bit lossless 60 fps may be possible. On 5D3, UHD and DCI 4K use sensor sizes of about super 35mm 3-perf to 4-perf. So they are very "cinematic". It will be exciting that 5D3 can do UHD/DCI 4K raw 60 fps slow mo.

[Bender@arsch]

Interesting discussion

Btw, the maximum writespeed on the 5D Mark III is not 135mb/s. The edge is somewhere else.
In my Tests I got 138mb/s and I wrote this in the Forum here.
https://www.magiclantern.fm/forum/index.php?topic=23041.msg230881#msg230881

But later I reached 139mb/s, but never more.
I reached this with the 3.5K Preset in 3584x1730, 23,976fps at 10bit lossless (tweaking from 14bit lossless) and with cardspanning, sd overclocking 160mhz and kill global draw (5x crop preview).
I stopped manually;) and this is not a high peek Number, this is a average number -> I double checked this on the computer.

[Jonneh]

In order to increase vertical resolution you need to increase FPS Timer B (increasing FPS Timer B decreases FPS) , I could do 1920x3072 1x3 @ ~20 FPS, but not in 24 FPS, in this case we need to lower FPS Timer B to get 24 FPS in 1920x3072 in 1x3 mode, but doing that broke the image and might freeze the camera . . it's weird because we didn't hit read out speed limit yet . . there are other *head* timers are related to FPS Timers, tweaking it are not enough . . maybe there are other registers needed to tweak . .

Fascinating how byzantine the gears and levers are that need to be moved to get a desired result. Proper detective work!

In LiveView the camera uses more memory cycles resulting in lower write speeds, lowering framerate from "FPS override" helps .

In my previous tests, maximum write speed with card spanning in PLAY mode is ~155 MB/s (5D3.123) using 160 MHz, 192 MHz and 240 MHz overclock presets, in LiveView the write speed decreases a bit due to more memory cycles are used which became ~135 MB/s write speed when the framerate @ 24 FPS . .

~155 MB/s write speed limit in PLAY mode is coming from the memory (RAM), so I think it's a memory speed limit here . . bypassing this memory speed limit somehow may increase card-spanning write speed in theory . .

I see---that makes things clearer. So the 155MB/s is a RAM bottleneck and the 135MB/s (or 139, per Bender's current record) is the same minus the LiveView overhead. I'm sure I'm missing something obvious here, but what is PLAY mode? As I know it, it's just for playback, and no writing occurs there.

[theBilalFakhouri]

..
Btw, the maximum writespeed on the 5D Mark III is not 135mb/s. The edge is somewhere else.
In my Tests I got 138mb/s and I wrote this in the Forum here.
..

But later I reached 139mb/s, but never more.
...

Yeah, never said it's exactly 135 MB/s . . I always added the approx sign before the numbers "~135 MB/s" . . at some point I also got ~138 MB/s write speed, let's say it's around these numbers ~135 MB/s to ~139 MB/s write speed using card spanning (23.976 FPS)

I'm sure I'm missing something obvious here, but what is PLAY mode? As I know it, it's just for playback, and no writing occurs there.

We use PLAY mode for running cards benchmarks since in this mode there is no overhead happening by anything, so this mode gives us the highest CF/SD card controller speed.

[Jonneh]

We use PLAY mode for running cards benchmarks since in this mode there is no overhead happening by anything, so this mode gives us the highest CF/SD card controller speed.

Gotcha---good to know!

[masc]

I'll try to answer all the MLVApp questions...

In MLV App latest version, if a low contrast lens is used and sky is overcast, I use 81 contrast, 81 clarity (microcontrast), 81 chroma separation- sharpening.

I wonder if it has something do do with the order of operations, such that MLV App is sharpening before stretching, but if ILA_ML is getting good results (and given that ilia knows what he's doing), that seems unlikely.
Do you happen to know what MLV App uses by default?

Don't use the MLVApp sharpen sliders for anamorphic footage. Stretching is done after sharpening, so you'll get bad lines. Better sharpen after the export in your NLE. By default, MLVApp doesn't sharpen at all.

If MLV App has a transformation/debinning algorithm to reverse engineer the Canon binning process, or has an AI algorithm to guess right the original 3 pixels from this fat pixel, then the anamorphic UHD will be very close to the native UHD.

You can't undo binning. You can just use better and worse algorithms for unsqueezing: most applications use bilinear or bicubic for this job. MLVApp uses AVIR, which brings better stretching results.

I once accidentally underexposed my footage, after elevated the exposure in MLV App for about 3 stops, the noise made the footage not usable. Yet 5D3's low light performance is pretty good in photo mode.

The results should be the same between photo and video mode. And if you use the same applications for processing, you'll notice that. MLVApp brings very similar results to Adobe ACR - just ACR has a denoiser enabled by default (switch it off and it looks mostly identical). When using defaults, processing video in MLVApp and photo in ACR, you'll thing photo is better - but it isn't.

[mlrocks]

I'll try to answer all the MLVApp questions...Don't use the MLVApp sharpen sliders for anamorphic footage. Stretching is done after sharpening, so you'll get bad lines. Better sharpen after the export in your NLE. By default, MLVApp doesn't sharpen at all.
You can't undo binning. You can just use better and worse algorithms for unsqueezing: most applications use bilinear or bicubic for this job. MLVApp uses AVIR, which brings better stretching results.
The results should be the same between photo and video mode. And if you use the same applications for processing, you'll notice that. MLVApp brings very similar results to Adobe ACR - just ACR has a denoiser enabled by default (switch it off and it looks mostly identical). When using defaults, processing video in MLVApp and photo in ACR, you'll thing photo is better - but it isn't.

Thank you very much for the instructions on MLV App, masc. It is very nice to know these tips.

[mlrocks]

I just did a test on 5D3 in the following modes: 1x1 UHD, and 1x3 anamorphic UHD. All in 10-bit color depth, 14-bit lossless compression. Aspect ratio was set to 3 to make 1x1 UHD continuous. The scene was composed of side trees with dense green leaves, an apartment gate, a parking lot with cars. The focus length of the lens was about 28mm. I used MLV App to process the raw into prores 4444. The footage was viewed in Potplayer on my computer screen of 27 inch 1920x1080 in full screen mode. I can see that the details of leaves are noticeably better in 1x1 UHD mode than in 1x3 anamorphic UHD mode. For the apartment gate and the park lot and the cars, the difference is not noticeable.
I have a little concern here with this experiment. The 1x3 anamorphic UHD is not an independent mode on 5D3. It is in the anamorphic mode, but can choose the horizontal resolution of 1280. Not sure if this UHD submode is optimized enough. I tested on 650D anamorphic UHD which is an independent mode and the results for the same scene (different dates, maybe different time of the day) showed that tree leaves were pretty sharp. I will do more controlled tests on this aspect.
Right now, probably IDA_ML's experiment is more convincing. Hopefully others can do more tests on 1x1 versus 1x3 modes using different approaches, such as similar experiments on an Apple 5K Retina monitor, etc, so that the conclusion will be more solid.

[IDA_ML]

I can see that the details of leaves are noticeably better in 1x1 UHD mode than in 1x3 anamorphic UHD mode. For the apartment gate and the park lot and the cars, the difference is not noticeable.

I am wondering what is so special about the green leaves.  Is it the green color, maybe, that causes the trouble?

[Jonneh]

Don't use the MLVApp sharpen sliders for anamorphic footage. Stretching is done after sharpening, so you'll get bad lines. Better sharpen after the export in your NLE. By default, MLVApp doesn't sharpen at all.

Good to know. Does this order of precedence have to be the way it is? Intuitively, I would think that most operations, and not just sharpening, would be best done on the resized image, but I could be wrong about that. I don't typically need (like) to sharpen, so it's unlikely that I did when I noticed the artefacts, but I'll bear it in mind for when I do a comparison and troubleshooting. By "default", I was actually referring to the resizing algorithm---good to know it's AVIR.

I just did a test on 5D3 in the following modes: 1x1 UHD, and 1x3 anamorphic UHD.

Out of curiosity, do you have a DNG (or just a jpeg) of the anamorphic shot where you see the difference in quality in how the leaves are rendered? I'd be interested in seeing if our results are comparable. If not, any jaggies and colour artefacts, or just a general softness? And did you focus on the trees or somewhere else (depending on this distance, all may be in focus with a 28mm, so this might be moot)?

I'll do some tests of my own in a few days' time. I have the 100D with its own anamorphic mode to compare results

NB: Interesting reflections on the state of the industry vis-à-vis motion blur and resolutions in your last reply to me. Good to hear from someone following these trends---I'm just a hobbyist who doesn't watch series. I'm told I should.

I am wondering what is so special about the green leaves.  Is it the green color, maybe, that causes the trouble?

I always assumed it was the high contrast of a backlit object combined with the typical intricacy of branches and leaves. I've seen similar problems on silhouetted trees, so I don't think it's the green, although it was a plausible guess!

[mlrocks]

I am wondering what is so special about the green leaves.  Is it the green color, maybe, that causes the trouble?

I guess that the dense details caused the problem. Most people use this foliage test for wide angle landscape challenge against the camera or the lens to check the weakness.

[mlrocks]

Good to know. Does this order of precedence have to be the way it is? Intuitively, I would think that most operations, and not just sharpening, would be best done on the resized image, but I could be wrong about that. I don't typically need (like) to sharpen, so it's unlikely that I did when I noticed the artefacts, but I'll bear it in mind for when I do a comparison and troubleshooting. By "default", I was actually referring to the resizing algorithm---good to know it's AVIR.

Out of curiosity, do you have a DNG (or just a jpeg) of the anamorphic shot where you see the difference in quality in how the leaves are rendered? I'd be interested in seeing if our results are comparable. If not, any jaggies and colour artefacts, or just a general softness? And did you focus on the trees or somewhere else (depending on this distance, all may be in focus with a 28mm, so this might be moot)?

I'll do some tests of my own in a few days' time. I have the 100D with its own anamorphic mode to compare results. For my rough test, the leaves were noticeably softer in 1x3 than 1x1. I did not see significant chroma abberation.

I will do more rigorous test later. I need compare 650D's UHD modes with 5D3's UHD modes. It may take several weeks due to not enough free time. Stay tuned.

NB: Interesting reflections on the state of the industry vis-à-vis motion blur and resolutions in your last reply to me. Good to hear from someone following these trends---I'm just a hobbyist who doesn't watch series. I'm told I should.

I always assumed it was the high contrast of a backlit object combined with the typical intricacy of branches and leaves. I've seen similar problems on silhouetted trees, so I don't think it's the green, although it was a plausible guess!

I did not have a dng shot for the scene to compare the video footage. I think IDA_ML already did that test.

[Jonneh]

I did not have a dng shot for the scene to compare the video footage. I think IDA_ML already did that test.

Oh, I just meant a DNG corresponding to one frame of the video, not a CR2 raw file, but you may not have the file in that format. A jpeg screen capture would do, but not to worry otherwise.

[mlrocks]

Oh, I just meant a DNG corresponding to one frame of the video, not a CR2 raw file, but you may not have the file in that format. A jpeg screen capture would do, but not to worry otherwise.

I did not do that. In this rough test, the footage in 1x3 was noticeably softer than 1x1. But it might be due to other reasons. In the near future I will do more controlled test to eliminate or at least reduce the confounding factors.
I think IDA_ML's approach and results should say enough that 1x3 is good enough. My original purpose of this rough test was to see if the footage in video mode would even reduce the difference.

[mlrocks]

I just did an experiment. The scene was composed of side trees with dense green leaves, an apartment gate, a parking lot with cars. The evening sun lightened some part of the scene. There was strong wind. I used one lens on 5D3 and 650D. The cameras were set up on a tripod. The whole experiment was done within 30 minutes. The focus length of the lens was about 28mm. All of the parameters in MLV App were default (except one footage I will mention it later). I used MLV App to process the raw into prores 4444. The footage was viewed in Potplayer on my 27 inch computer monitor of 1920x1080 in full screen mode.


The following modes were tested:

5D3 1x1 UHD
5D3 1x3 anamorphic UHD 10 bit color depth
5D3 1x3 anamorphic UHD 14 bit color depth
5D3 1x3 5.7k anamorphic 10 bit color depth
5D3 1x3 5.7k anamorphic 14 bit color depth
650D 1x1 3K
650D 1x3 anamorphic UHD 10 bit color depth
650D 1x3 anamorphic UHD 14 bit color depth

The common acquisition parameters were 14-bit lossless compression. Aspect ratio was set to 3 to make all modes continuous. The acquisition period was 1 minutes for each take.


Here are my observations:

First, 10 bit color depth modes and 14 bit color depth modes were not different in terms of IQ, because the MLV App parameters were default.

Second, confirming my previous experiment, I can see that the details of leaves were noticeably better in 5D3 1x1 UHD mode than in 5D3 1x3 anamorphic UHD mode. For the apartment gate and the park lot and the cars, the difference was not noticeable. Some of the trees had wind shake, so the difference was not noticeable. Thus, motion blus will mask the difference.
However, the difference of 5D3 1x1 UHD mode and 5D3 1x3 anamorphic UHD mode was much greater than the difference of 650D 1x1 3K and 650D 1x3 anamorphic UHD. In addition, 5D3 1x3 anamorphic UHD 14 bit color depth footage meta data were not recognized in MLV App, so I had to manually change the stretching ratio to 0.33. I suppose that the 5D3 1x3 anamorphic UHD submode is not optimized. I recommend not using this mode, even for testing. It will be great to have a separate preset of 1x3 UHD 60 fps on 5D3.

Third, 5D3 1x3 5.7k anamorphic was as detailed as the 5D3 1x1 UHD, if not more. Actually watching these footages again, I think that 5D3 1x3 5.7k anamorphic was noticeably a little bit sharper than 5D3 1x1 UHD, not much though. Therefore, there is no advantage to use 5D3 1x1 UHD, considering that 5D3 1x3 5.7k anamorphic 14-bit color depth is continuous, except that 5D3 1x1 UHD has much shorter processing time in MLV App. In the future, a test on the details of 5D3 1x3 5.7k anamorphic vs 5D3 1x1 5.7k will be more proper. If the difference in IQ is not significant, as demonstrated on 650D, I would rate 5D3 as a 6K Raw camera. Red Komodo users, BMPCC 6K Pro users, Canon C500 MKII users are welcome to challenge this claim.

Forth, 650D 1x1 3K was the sharpest of all the modes tested, 650D 1x3 anamorphic UHD was very close to 650D 1x1 3K in terms of IQ details. The sharpness of these modes is consistent with my previous experiments on 650D, so I consider that it is true. I am confident that the general audience will not see the difference between the 650D 1x3 anamorphic UHD and the 650D 1x1 3K in many commercial theatres with 2K projectors, neither by watching cable TV, nor by watching internet streamed videos. Therefore, for myself, I will use 1x3 anamorphic UHD 14-bit color depth on 650D as the main mode. It has a data flow of 55 MB/s thus continuous on 650D. I would rate 650D as a 4K Raw camera. BMPCC 4K users, Canon C70 and/or C200 users are welcome to challenge this claim.

Fifth, I am surprised to see that 650D modes were noticeably sharper than 5D3's. More experiments are needed to verify if this is true.


Future directions:

All of the above observations are based on "unprocessed" neat footage. I will do PP for each footage to improve the IQ. I think that PP will mask or at least mitigate the difference observed.

More studies with different approaches to test 1x1 vs 1x3 modes by community members are helpful. I am curious to see if results from similar experiments viewing on a 5k monitor will be the same.

[IDA_ML]

Forth, 650D 1x1 3K was the sharpest of all the modes tested, 650D 1x3 anamorphic UHD was very close to 650D 1x1 3K in terms of IQ details. The sharpness of these modes is consistent with my previous experiments on 650D, so I consider that it is true. I am confident that the general audience will not see the difference between the 650D 1x3 anamorphic UHD and the 650D 1x1 3K in many commercial theatres with 2K projectors, neither by watching cable TV, nor by watching internet streamed videos. Therefore, for myself, I will use 1x3 anamorphic UHD 14-bit color depth on 650D as the main mode. It has a data flow of 55 MB/s thus continuous on 650D. I would rate 650D as a 4K Raw camera. BMPCC 4K users, Canon C70 and/or C200 users are welcome to challenge this claim.

This is exactly why the 1x3 UHD/24 fps/12bit lossless is my mode on the EOS-M too which, as far as I know, has the same sensor as the 650D.  I am glad to see that you came to that conclusion too.  Yes, processing time is longer in MLVApp but it is well worth it.  The results are way better compared to the 3x3 mode, that I was filming in before, especially in terms of aliasing, finest detail rendering and tone transition smoothness.  It simply looks much better on full screen, period.  What I usually do is let the laptop process all my footage overnight and when I wake up in the morning it is ready for video editing in Resolve.

And thank you for the extensive experiments, Mlrocks!  I am sure, after reading this thread, many people will fall in love with the 1x3 anamorphic mode on ML capable cameras.  And if Masc and Ilia could think of some magic to fix the "green leaves" issue in the 5D3, that would be absolutely fantastic!

[mlrocks]

This is exactly why the 1x3 UHD/24 fps/12bit lossless is my mode on the EOS-M too which, as far as I know, has the same sensor as the 650D.  I am glad to see that you came to that conclusion too.  Yes, processing time is longer in MLVApp but it is well worth it.  The results are way better compared to the 3x3 mode, that I was filming in before, especially in terms of aliasing, finest detail rendering and tone transition smoothness.  It simply looks much better on full screen, period.  What I usually do is let the laptop process all my footage overnight and when I wake up in the morning it is ready for video editing in Resolve.

And thank you for the extensive experiments, Mlrocks!  I am sure, after reading this thread, many people will fall in love with the 1x3 anamorphic mode on ML capable cameras.  And if Masc and Ilia could think of some magic to fix the "green leaves" issue in the 5D3, that would be absolutely fantastic!

Thank you for your enlightment on 1x3 anamorphic modes, IDA_ML. I can tell that you have extensive experience and have passion for 5D3 and ML. ML will be a landmark in the history of digital cinema camera. Cheers!

[mlrocks]

To be conservative, based on experimental data, I would confidently rate 5d3 ML as a full sensor vista vision 14-bit color depth 4K Raw cinema camera. 5D3 ML's 14-bit color depth 5.7K 1x3 anamorphic footage is as good as any top end 4K Raw cinema camera. ML's 14-bit lossless compression raw is equal to the uncompressed Arri Raw, better than Red Raw, BRaw, Sony Raw Lite, Canon Cinema Raw Lite, even at their best compression ratios. 5D3 ML's overheating issue can be solved by frequently turning off the camera during the takes. Considering the booting time of 5D3 ML is less than 10 seconds, instead of minutes on Red cameras, this is a practical measure. Also, two or more 5D3 ML can be used in turn to have time to cool down. Therefore, even in mission critical professional shooting environment, the overheating issue can be solved.

I would rate 70D ML as a super 35mm 10-bit color depth 4K Raw run-and-gone camera. 70D has a maximal writing speed of 80 MB/s, can be implemented with a preset of continuous 10-bit color depth 14-bit lossless compression 1x3 anamorphic 5.2K raw 24 p AR 2.4. 70D ML's 5.2K 1x3 footage may well be equal to Red and Black Magic cameras' 4K raw with a compression ratio of 12. With its excellent video AF and on-camera flip LCD screen, 70D ML can be used on steadicam or on drone, etc.

It is generally agreed that 4K Raw is good enough for theater size large screen. With several 5D3 and 70D cameras in the bag, with vision and passion, MLers are ready to rock out Hollywood features.

Good job, ML and MLers.

[mlrocks]

To bust another million dollar myth to benefit MLers, Arri's Alexa and Amira series excel in high light rolling off that no other camera can match, which is the best selling point of Arri to charge 10 to 50 times more than other cameras like 5D3 ML. In real world shooting, cinematic setup typically is controlled environment, meaning that the lighting can be controlled. You can use lighting to reduce the DR. Therefore, you are buying $100k over 5D3 ML as an insurance, but not a guarantee that your final footage will be better when using Arri Alexa than when using 5D3 ML. On the contrary, the footage may be very close and intercuttable if the lighting is set up right.
Arri's Alexa and Amira series are best used for uncontrollable environment, when the lighting can not be controlled, such as news gathering. I think that Arri Amira may be the best news shooting camera. However, you will be happy that your backbone is not broken after a whole day of shoulder shooting with Arri Alexa or Amira. On the other hand, nobody appreciates that you are shooting news with Arri Cameras, including the news agency, the common TV audience. They can tell the difference, but they don't care. Because it is just one time piece.
The truth is that you are buying Arri Alexa for insurance, for that prestigious big top brow camera looking to impress your customers on site, not really for the cinematic or filmic look the internet is raving about. With the proper lighting setup, 5D3 ML can do the same as the Arri Alex and Amira do.

[IDA_ML]

Also, two or more 5D3 ML can be used in turn to have time to cool down. Therefore, even in mission critical professional shooting environment, the overheating issue can be solved.

If you watch this tutorial by Masc:

https://www.magiclantern.fm/forum/index.php?topic=25180.msg231798#msg231798

you will see that he is not using SD-overclocking at all and he gets continuous recording at the anamorphic 5,7k/12 bit lossless/24 fps/2,35 AR setting.  At my daughter's graduation party I used the 5D3 extensively all day long and its temperature never exceeded 56 deg. C.  In my experience, overheating is not really an issue when filming UHD 1x3 anamorphic on the 5D3 and SD-overclocking is not really necessary.

One more word about 10-bit recording.  As you have noticed there is not really a difference in image quality between 10 and 14 bit lossless.  The only issue that you may experience with 10 bits is in high-contrast scenes if you severely crush the darkest areas.  In that case you get these ugly brown-redish colors in the crushed areas, (more pronounced on the EOS-M than on the 5D3).  That is why I always try to expose to the right until zebras start appearing and then I dial the exposure back by some amount to protect the highlights.  I always use a VND filter for that to preserve the nice full-frame vision with the narrow depth of field.  In this case severe crushing of the dark areas is very unlikely in most filming situations.   

I have also found that Dual ISO does a great job in reducing noise and protecting the darks in high-contrast scenes such as sun sets with the sun in the frame and night videography at street lights.  The 5,7k anamorphic mode provides enough vertical resolution for that, so that very beautiful high image quality videos with a filmic look are possible.

[mlrocks]

If you watch this tutorial by Masc:

https://www.magiclantern.fm/forum/index.php?topic=25180.msg231798#msg231798

you will see that he is not using SD-overclocking at all and he gets continuous recording at the anamorphic 5,7k/12 bit lossless/24 fps/2,35 AR setting.  At my daughter's graduation party I used the 5D3 extensively all day long and its temperature never exceeded 56 deg. C.  In my experience, overheating is not really an issue when filming UHD 1x3 anamorphic on the 5D3 and SD-overclocking is not really necessary.

One more word about 10-bit recording.  As you have noticed there is not really a difference in image quality between 10 and 14 bit lossless.  The only issue that you may experience with 10 bits is in high-contrast scenes if you severely crush the darkest areas.  In that case you get these ugly brown-redish colors in the crushed areas, (more pronounced on the EOS-M than on the 5D3).  That is why I always try to expose to the right until zebras start appearing and then I dial the exposure back by some amount to protect the highlights.  I always use a VND filter for that to preserve the nice full-frame vision with the narrow depth of field.  In this case severe crushing of the dark areas is very unlikely in most filming situations.   

I have also found that Dual ISO does a great job in reducing noise and protecting the darks in high-contrast scenes such as sun sets with the sun in the frame and night videography at street lights.  The 5,7k anamorphic mode provides enough vertical resolution for that, so that very beautiful high image quality videos with a filmic look are possible.

Thanks a lot for your great tips, IDA_ML. It is good to not do SD overclock if using 5D3 in professional settings, thus there is no overheating issue. I agree that 10-bit lossless is good enough for most cases. I have not tried dual ISO much due to the monitoring difficulties. I will try more. Regards,

[mlrocks]

I just did a quick test on my 5D3, with card spanning on and sd card overclocking off. The following modes are continuous for 1 minutes on a relative complex scene, then I manually turned off the recording. The data flow calculated by ML was about 110 MB/s for both modes for the scene. So overheating can be avoided totally.

1. 10 bit color depth, 14-bit lossless compression, 5.7k 1x3 anamorphic raw, AR 2.67, 24 p
2. 10 bit color depth, 14-bit lossless compression, centered 3.5k 1x1 raw, AR 2.67, 24 p

The centered 3.5K is good for specific reasons, because this mode has a super 35mm/APS-C image circle, so EF-S lenses and lenses designed for super 35mm can be used in this mode, like Sigma 18-35 f1.8 and Canon 10-18mm F5.6 IS. 3.5k on super 35mm is actually the most optimized resolution, more than this number other side effects may show up. Arri Alexa Classic uses a 3.4k super 35mm sensor, the latest Arri LF uses two of the same sensor, and the Arri 65 uses three of the same sensor. It seems that Arri considers 3.4k is the resolution limit for a super 35mm sensor size. And 5D3 has a 3.5k super 35mm sensor within.

[mlrocks]

For the 650D, I did a quick test, with 4.5k 1x3, 10-bit color depth, 14-bit lossless compression, AR 2.67, 24 fps, the data rate calculated by ML was about 36 MB/s for a complex scene. So 5.2k 1x3, 10-bit color depth, 14-bit lossless compression, AR 2.67, 24 fps, seems continuous on 650D with SD card overclocking at 240 hz if such a preset is implemented. 5.2k 1x3 anamorphic will use the full APS-C/super 35mm sensor width, so there will be a lot of benefits. The resolution of this 5.2k 1x3 may be close or even indistinguishable to native 4k 1x1.