Messages

Spot meter show %. But it basically correspond to IRE on the waveform.
40% is 18% gray. Actually measured 42-44% with Canon 5D Mark III and ML spot meter, but fairly close

For linear video profile as Canon RAW, typical values for human skin tones are:

Lightest skin: 60 - 65 IRE or 62-67% on the spot meter
Darkest skin:  45 - 50 IRE or 47-52% on the spot meter

It is easy to check those values if you load a part of the movie or video in resolve and check values on waveform scope. You'll see they fall most of the time within those values.

You have to put the spot meter on the brightest part of the face as it is rarely evenly lit

The nice thing with False color is that with a single glance I can also check if there are part of the image which are overexposed or underexposed and also if skin tones are within the range.

Why not use False Color in ML ? Many reasons:
1. False Color requires processing power so everything else slows down.
2. Many clicks to switch it on and off. On a monitor it is just one click of a button or on the touch screen. Maybe it can be assigned to a button on ML as well. Never tried. While spot meter is on all the time and you can immediately see the value. 
3. Low resolution LCD not practical for the purpose
4. Small LCD on the back of the camera - leads to limited monitoring and camera movements. Uncomfortable to monitor, frame and shoot that way unless on a tripod or monopod with a LCD viewfinder on LCD

IMHO Spot meter would be the best. You can set exposure very precisely. In other cameras would use False color. But on the tiny low res LCD of EOS M or Canon 5D Mark III with ML spot meter function would be my friend when trying to set correct exposure on human faces.

In my experience ML RAW is like Canon RAW photos. It has more latitude toward underexposure than overexposure. Which means you can miss and recover more stops when underexposed than when overexposed. That's why I never use ETTR method with ML RAW. ETTR is mainly for log profiles on modern cameras where you need to overexpose at least 1 stop even 2 in order to get rid of the noise.

Lack of monitoring in more interesting and high image quality modes as crop is the reason why I rarely use 5D Mark III and EOS M with ML nowadays. It's a major pain in the a.. . In 1080p can use external monitor which is much more comfortable for setting exposure and focus and even more importantly - framing. Every cheap Chinese monitor has False color and wave form as tools. False color is by far my favorite one, perfect for exposure of people and skin tones. I never missed correct exposure with False Color. Never, not even once. But again in ML land external monitors work only in normal 1080p mode. And are not usable or even work with higher image quality modes as crop and anamorphic.

You are absolutely right ! Nothing wrong with recording. It played OK in camera, no damaged frames. Card reader is OK actually, when plugged to a fast USB 3.0 port it works OK
Problem was when card reader was on a slow USB2 port. Never had a problem with this USB 2 port. It was slow but worked.

Anyway, thanks for the help and apologies for bugging you with something that is way off ML
But sometimes it's just a bad day and my brain doesn't work as it should

By the way with kill global draw 3584x1730 (2:1 my favorite ratio) at 10 bit recording times are excellent. Way more that expected !
Again thanks a lot for your work and help.

Always used 2:1 ratio. And until recently it worked without any problem
Here is a test with 2.35:1 ratio set in presets:

https://ibb.co/SB4jt9B
https://ibb.co/XzWNQDc

Still bad. Thought that breaking point is card spanning. But it's not.  Tested 3K crop, anamorphic 2.35:1 ratios.  All bad even when using only the CF card
Only 1080p normal mode works OK.
It's really strange. Will try to reset everything later and start again from scratch. 

P.S. Will wait some time to clear my head, then reset everything and start from scratch.

Tried on the second set of SD + CF cards - same (bad) result.
Writing speeds are good. But green indicator on 3.5K, 2:1 ratio, 10 bit at 3584x1730 resolution ?
Hmm this is kind of fishy. Never had this before.

https://ibb.co/61GJrK7

Before writing speed indicator was yellow at best and red most of the time. Which is expected in such a high resolutions
But for relatively short clips it worked well and without major problem.

Here are my settings:

https://ibb.co/Y0XRdDc
https://ibb.co/zSTnBb8
https://ibb.co/TwpfRhH
https://ibb.co/xXSr6jp

24fps in camera and same in MLV when open the files.
Also 3K is the same. As far as card spanning is enabled all crop modes are affected
Tried : Kill global draw - on and off, no effect.

Firmware version 1.2.3, latest from you at 1st of April 2021. Unfortunately didn't kept previous versions to test
Previous day formatted a second SD card, copied the firmware and discovered that had to do the installation on that card too.
Otherwise ML won't load from the card. Apparently it has to set the some flag on the card not just in camera ?
Wanted to have a second set of cards (SD+CF) as one was not enough to go trough the day and shooting
And it worked OK for a day. Then it went totally crazy. It seems this second installation somehow messed things up

Followed your advice: Uninstalled ML, format both SD and CF cards in camera. Reinstalled ML on SD card.
Same (bad) result when trying to write on both cards at 3.5K crop.

https://ibb.co/chKbzm2
https://ibb.co/Fnmg2Gh

Problem with crop modes and card spanning:

5D Mark III in 3.5K crop mode. It worked OK for several days. But opened footage from last day and it's all garbage.
Tried different cards, result is always the same. As far as card spanning is ON and crop mode is 3K or 3.5K it's all garbage.
When shooting nothing suggested that there is a problem. Most of the time indicator is green which is kind of surprising. In 3.5K it is yellow most of the time or red with limited filming time.
Maybe messed up with a setting ? Green indicator is kind of hint in this direction.
ML version is the last one from Danne (April 2021)

Check the frames bellow. Any ideas why ?

https://ibb.co/R3Lzx1f
https://ibb.co/MNJHZJ6

Thanks a lot for the latest build, Danne. It's oustanding ! 3.5K 2:1 aspect ratio at 24fps 1.6 crop. It's basicaly 4K Super35 (APS-C) format. Just perfect for me !
Don't need anamorphic modes anymore. 

Not sure if this is a problem or not but modules don't show on the menu.
See only two of them atg_gui and bench. But can see them in the respective folder.
Is this a bug or by design ?

When bench marking a SD card instead for some values for read performance get this message:

          malloc error buffer: 16777216

Two difference Sandisk Pro 128G cards, same message.

But the work and report write speeds of 50mb/s

Question about anamorphic fullres mode:
Currently it is fixed to 15fps.  Is is possible to increase frame rate ? Tried to use FPS override but camera locks and freezes. Have to pull the battery out in order to make it operational again.

With SD card overclock + card spanning in theory can get 1800 x 2700 12 bit or even 1920 x 2880 10 bit running at 24fps for at least 10-15 sec, which is enough for me. 2:1 is my favorite aspect ratio.

[Micro Four Third lenses only]

C-mount lenses are not an option. Been there, tried some of them. Very low quality optics made mostly for security cameras or machine vision that don't do justice to crop mode resolution
Simply skip them and don't waist your time and money.

Not many wide angle lenses for crop mode, but still some:

Fish eye lenses:

Samyang / Rokinon 7.5mm f3.5  - 190gr 250$
Samyang / Rokinon 8mm f2.8     - 260gr 260$
7Artisans 7.5mm f2.8                  - 278gr 140$

They all will give you angle of view equivalent to 24mm-28mm FF after correction in Davinci Resolve and do exists for EOS M

Regular / rectilinear lenses:

Laowa 7.5mm f/2 MFT   150gr (Lightweight Version) / 500$
SLR Magic 8mm f4          130gr  / 140$

Both are made for drones as one of main applications. Laowa is rectilinear and near perfect - sharp wide open, f2 aperture. Could be used for night shots. But relatively expensive.

But both are Micro Four Third lenses only. You'll have to find somebody to change the bayonet for you to Canon EOS M. And this will cost you even more money. A local guy have done this for me for many other lenses but decided to buy a better camera and abandoned the project

For scenery / landscapes used mostly Canon 10-18mm with regular adapter. 35mm FF equivalent angle of view which is my favorite. But drones typically use 24mm-28mm.

Did somebody tried Viltrox EF to EF-M speedbooster + Canon 10-18mm combination on EOS M?

Had high hopes for it. Would be perfect for those crop modes. 

But so far it doesn't work.  Yes had to cut the back of the lens first. 

Viltrox EF to EF-M speedbooster + Canon 18-55mm IS II (with back cut off) works no problem at all. Viltrox + Tokina 11-16mm f2.8 also works. Canon 10-18mm works on Full Frame Canon bodies (some limitations on Mark III), works on Sony cameras with cheap Chinese adapters. But not with the Viltrox. Canon EOS doesn't recognize the lens when Viltrox speedbooster is used.

And by the way Viltrox Speedbooster has an adjustment for infinity. The whole group of lenses moves forward / backward when you rotate them from the inside.
https://www.youtube.com/watch?v=vu_rVCw5cGU

Manage to find a position where infinity is OK but the lens of the speedbooster is back enough so Canon 10-18mm @10mm doesn't hit the glass. Lens could be used trough the whole range of focal lengths.

Now only if speedbooster would recognize the lens 

Thank you Danne and optical-work for the help! Setting preview to 'framing' indeed made live view work as wanted and expected.
Was not aware that lua script was not needed anymore. Formatted the card, installed ML latest version and message about sd_uhs is gone. Maybe there is an easier way to stop lua script but this one works too

Many thanks to Danne and others for the great work that made EOS M such a nice raw video camera ! 

When using last version from 24th of March get always a message at the start:

Please enable sd_uhs module.

But this module is enabled. Somehow ML doesn't recognize it. Is somebody else getting this error or it's just me ?

Reverted back to the 14th of March version and there everything is OK. sd_uhs is recognized and started with the start of the camera.

Another small issue is with live view and custom ratios.

Using 2.5K 2520 1418 mode from crop_mode menu

With standard ratio of 2.35:1 set by the script in crop_mode menu, live view works correctly. Image is refreshed at slower rates and turns black and white when recording but presents a correct view of what will be recorder. This in my understanding and experience is how live view works in crop mode.

But my preferred ratio for video is 2:1. And in order to get it follow Danne's instructions in previous post:
   - 2.35:1 ratio in crop_mode is turned off
   - change the ratio to 2:1 and resolution 2400x1200 in RAW_video menu. 2520x1250 doesn't give me enough seconds of recording so I lower the resolution a bit

But at this point live view doesn't work as it was working when 2.35:1 ratio was set. It turns to x5 crop. So I see only a portion of the recorded image. Only when half pressing the shutter, then see the picture as it will be recorded - at lower fps and as it was when ratio is 2.35:1.

So my question is: Is this behavior by design ? And could it be made to work consistently across all ratios ?