Canon EOS R5 / R6

Started by SiSS, February 15, 2020, 01:53:06 AM

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Levas

Wanted to know some more how the camera(Canon R5) behaves under different modes and different iso settings.
Shot some dark frames in different photo and video modes and loaded the into raw digger to calculate dynamic range based on noise.

Made a spreadsheet in google drive with some more info about the Canon R5:
https://docs.google.com/spreadsheets/d/1D3lpiMQniUzPiaVqDzAs5Gmc2hR9mIjDXpDe5IBTP9E/edit?usp=sharing

What suprises me are the different black levels.
In photo mode in iso 100 and iso 200 it's about 512.
While in all other iso modes it becomes 2048 (which is normal for most Canon camera's with digic 5 with ML support).
In raw video mode black level is 1024, all iso's also iso 100 and 200.

The Canon 6d always has black level in the 2048 range, unless when shooting 12 bit or 10 bit raw, then it becomes 512 and 256)
Does this mean that the Canon R5 is using 13 bit a/d conversion for video modes ? (would explain the black level shift from 2048 to 1024)
And what is going on with iso 100 and 200 in photo mode, the only modes where black level is 512, can't be because 12 bit a/d conversion I guess, dynamic range is highest at iso 100  ???

Furthermore, it seems that iso 200 can be best avoid(dynamic range wise), if 100 is not enough, you can go directly to iso 400  :P
Also, after iso 3200, every more stop of iso is a direct stop loss in dynamic range, so there is probably not much reason to shoot higher then iso 3200, since digital exposure push in post should give similar results.

So anyone has any idea what's going on with the different black levels, especially the black level of 512 with iso 100 and 200 in photo mode?

Levas

What is also interesting, when shooting raw video in the raw lite codec, which has a compression ratio of 6:1instead of normal raw which has 4:1 compression ratio.
The max white value of both green channels become about 10780, not 15359. (16383(max 14 bit value) - 1024(black level) = 15359)
Both the red and blue channels still have 15359 as maximum white level.
So the extra compression is achieved with using lower values for green channels, which according to the measurements done with dark frames doesn't impact dynamic range.
Weird enough, there seems to be a slight advance in dynamic range when shooting raw lite instead of normal raw  ???.
Although this probably comes with a penalty of less fine detail, since the green channels seems to contain more noise reduction done already in camera, or the standard noise reduction kicks in more because of the lower values.

Levas

For those interested, some comparison of raw video against the 6d.
Was hard to do, not easy shooting the same scene and layering the footage and matching colors etc.  :P

8k raw of the R5 scaled to ultraHD matched to aspect ratio of the 3x1 mode of the 6d.
It starts with R5 footage and wipes to 6d footage (3x1 mode, 1832 x 1856 -> 5496 x 1856 resolution scaled to ultraHD)
The footage is very comparible, but R5 wins on detail, far more detail in the leaves.
And the R5 can shoot more usable aspect ratios of course  :P (R5 footage aspect ratio is matched to 6d 3x1 mode.).
https://drive.google.com/file/d/1c059wQoWCMJmlSClCrJ7aq2N7DgEv2r8/view?usp=sharing

Another comparison, here the 6d is used in crop mode 2880 x 1200.
The 6d footage is placed on the R5 footage which uses the whole frame.
So the frame somewhere in the middle is the 6d footage.
https://drive.google.com/file/d/1ktI5tKHdYd80gjpT6c5AdFYYRvTDsdVq/view?usp=sharing

c_joerg

Quote from: Levas on June 10, 2022, 07:44:37 PM
The Canon 6d always has black level in the 2048 range, unless when shooting 12 bit or 10 bit raw, then it becomes 512 and 256)
I don't have 6D anymore, but how could you shoot 10 bit RAW with it?

Quote from: Levas on June 10, 2022, 07:44:37 PM
So anyone has any idea what's going on with the different black levels, especially the black level of 512 with iso 100 and 200 in photo mode?

We had some trouble with my G1x and the Black level. This is also issue for some P&S.
The M100 changes its black level from 512 to 2048 at around ISO320.

May be something interesting for you:
https://chdk.setepontos.com/index.php?topic=12165.30
https://chdk.setepontos.com/index.php?topic=7069.0

But is changing black level from 512 to 2048 losing of 2 Bit?
If I have a maximum exposed pixel with 16383 and I half the exposure, then theoretically the value goes 16383/2 = 8192.
What I see is on my G1x:

With black level 512  =>   ((16383 - 512) / 2 ) + 512 = 8848
With black level 2048  =>   ((16383 - 2048) / 2 ) + 2048 = 9216

The RAW values in 1EV steps with black level 512 can be seen here

https://chdk.setepontos.com/index.php?topic=12165.msg126374#msg126374

EOS R

70MM13

That's a great comparison, thanks very much!
The darks were far better on the R5 also.  Nice and crisp detail on the trunk of the beech tree.  The 6D was just mud.

If you are so motivated, a comparison of a very dark scene would be much appreciated, with the shadows lifted several stops...

Levas

@C_joerg
Interesting, so black level changes happen on more canon cameras.
Not sure if I understand the stuff discussed in the links you send.
So am I right that one theory is that the camera actually uses a lower iso then it actually reports ?
So in case of the Canon R5, which only has black levels of 512 in iso 100 and 200, you think it actually uses a lower iso/gain, like 25 or 12.5 ?
Iso/gain is the only thing they can use,  a faster shutter speed or smaller aperture would both be noticed by people I guess.

The 10 bit and 12 bit raw recording is possible on the 6d with raw video recording in magic lantern raw.
This was done by using a register that act as digital gain, it pushes the values recorded 2 or 4 stops lower.
Now I think about it, that makes sense that in this case the black level becomes lower in value.
Digital negative gain also lowers the noise signal, so this means lower black level  ???

What I also see discussed in the links you send, is that the image data is rescaled in the raw files in camera.
This is also the case with the R5, max white value is always at 16383 - black level.
This makes it difficult to see what is going on...

The whole iso magic is also happening with clog1, clog3, highlight tone priority etc.
Minimum iso that is possible in 8k raw:
No log -> iso 100
Highlight tone priority enabled -> iso 200
Log1  -> iso 400
Log3 -> iso 800

When actually using the above settings and iso, and load the files in raw digger, you can see in the noise level that it's all the same, it's all recorded in iso 100 :P



nikki

i like the 6d footage better

HondaATC

Been a while since I was on the ML forums - recently upgraded from a 5DMK3 finally to an R5, already missing some magic lantern functions...

didn't read through all 12 pages, do we have a semi-stable build that works on the R5 now?

names_are_hard


vastunghia

Quote from: HondaATC on December 22, 2022, 03:52:28 PM
Been a while since I was on the ML forums - recently upgraded from a 5DMK3 finally to an R5, already missing some magic lantern functions...

Would love to hear specifically which ML functions you are missing switching from 5D3 to R5. A genuine, non-rhetorical question.
5D3 for video
70D for photo

C0dR

Well regarding ML functions and Firmware development: wouldn't it be possible or even be easier to port cinema menu functions from the R5 C to R5, since they are almost the same camera and (i guess) most of the features are pure software implementation? I know this is far away from easy but just thinking maybe someone with more knowledge than me might poke around in the R5 and R5C firmwares and might find something interesting and/or usable?

Walter Schulz

Quote from: C0dR on December 23, 2022, 09:28:26 AM
Well regarding ML functions and Firmware development: wouldn't it be possible or even be easier to port cinema menu functions from the R5 C to R5, since they are almost the same camera and (i guess) most of the features are pure software implementation? I know this is far away from easy but just thinking maybe someone with more knowledge than me might poke around in the R5 and R5C firmwares and might find something interesting and/or usable?

Not gonna happen. It would be a violation of Canon's IP for sure.

Example what is considered to be allowed:
Canon introduced an electronic zoom for video in EOS 600D. Better image quality but cropped.
Same code was found inside 650D, 700D, 100D, EOS M. Just no menu item for the function to get accessed (simply speaking). So ML devs used what they found.

Example what is considered to be a no-go:
AF adjustments are not available for entry level cameras. Such code is not present in cam firmware then. It was asked several times to make it happen but it was declined because of IP issues.

HondaATC

Quote from: vastunghia on December 22, 2022, 09:54:17 PM
Would love to hear specifically which ML functions you are missing switching from 5D3 to R5. A genuine, non-rhetorical question.

Focus Peaking for video and zebras in over exposure places on image review are the main thing so far. Magic zoom was also really handy.

Seems like there was also some custom button programming I did that I can't figure out how to replicate on the R5 (like changing the ISO by holding the select button and just rolling the front switch). Maybe that was a normal canon setting but its been so many years ago I don't remember how i configured it.

Maybe the R5 can do all of these things, but I haven't figured out how yet.

vastunghia

Quote from: HondaATC on December 23, 2022, 01:24:20 PM
Focus Peaking for video and zebras in over exposure places on image review are the main thing so far.

I see. However with 5D3+ML in many cases focus peak and zebras (as well as raw histograms, fwiw) are pretty unusable — that is, they work bad with correct framing and are anyway hard to use with the small cam LCD (even with real time, cropped preview that is).

An external monitor does the trick I think, both with 5D3+ML and with R5. Actually, I guess you will also get correct framing with R5+monitor, which is not the case with 5D3+ML+monitor.

Just my 5 cents.

S
5D3 for video
70D for photo

fred_76

Hi, I did some review on the R6 Mark II, for low light photos only. It is in french here :
https://www.webastro.net/forums/topic/236222-test-complet-canon-eos-r6-mark-ii/

I also found it has the two offsets of 512 below 320 ISO and 2048 from 400 ISO.
The 200 ISO setting is worse (noise/dynamic) than 100 and 400 ISO.

Strange thing happens to the RAW when looking at the FFT of the bias images, two horizontal lines below and above the central module line... maybe due to Dual Pixels ?

Fred

kitor

For those wondering what the Digic X issues are, here is the list:

https://github.com/reticulatedpines/magiclantern_simplified/issues/80
https://github.com/reticulatedpines/magiclantern_simplified/issues/81
https://github.com/reticulatedpines/magiclantern_simplified/issues/82

TL;DR: Like I described in this post, memory management is interesting.
Camera appears to have 5GB of RAM (4+1) that maps somehow into <2GB of memory space on ICU.
There's a new resource manager that seems to handle that. There's not a lot of debug prints though, I tried to understand it for a few days but got nowhere.

I personally gave up on this for now, since I believe we have a whole backlog of Digic 6, 7 and 8 models to support. And as for now, only R5 and R6 would benefit anyway - as we already know newer R models have Canon Basic and UART ocked - which means there's no (easy) way to run the code on them... at least for now.
Too many Canon cameras.
If you have a dead R, RP, 250D mainboard (e.g. after camera repair) and want to donate for experiments, I'll cover shipping costs.

yourboylloyd

I understand giving up. Since the overheating isn't an issue anymore, I'm not sure how ML would benefit the R5 or R6 much anyway unless it can somehow let us do Open Gate recording.
Join the ML discord! https://discord.gg/H7h6rfq

Sapporo

R6 has 20,1 effective megapixels and 21,4 total megapixels. Including the optical black field to the left and top I get 5568x3708 pixels. Total 20646144 pixels. Where are the others? To the right and trashed before saving to card like 5D III?
https://d1hjkbq40fs2x4.cloudfront.net/2020-07-03/files/canon-eos-r6-image-sensor_2061-03.JPG

names_are_hard

Quote
R6 has 20,1 effective megapixels and 21,4 total megapixels

Got a source for that 21.4 MP?  I suspect it's just wrong.

theBilalFakhouri

Quote from: names_are_hard on April 02, 2023, 07:20:29 PM
Got a source for that 21.4 MP?  I suspect it's just wrong.

It's actually written on Canon UK, R6 specs:


Walter Schulz

Also found in EXIF data

And
Image Width/Height is 5472x3648

names_are_hard

Lots of different numbers from different sources then.

Listed image resolution is 5472 x 3648 (19.9MP?).  That's usable data I suppose.  Exif suggests 20.6MP.  Size with masked areas?

No idea how 21.4 is calculated.  Perhaps it's the same inflation that leads to 19.9 being reported as 20.1?

Walter Schulz

RAWtherapee tells the picture I used for Exiftool is actually 5488x3662=20,097,056 which is legally rounded to 20.1
No, don't ask me why exif shows different numbers.

Sapporo


names_are_hard

Could be.  I don't have an R6 so can't investigate (and don't care enough to bother anyway).