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[Speed Test: Samsung EVO Plus mSDXC UHS-I 256GB]

Speed Test: Samsung EVO Plus mSDXC UHS-I 256GB
R130/W130
Product Number: MB-MC256KA (MB-MC256K written behind the Card)
MDT: 2023/10
PRV: 3.0

Highest CropMood speed reached for a 1 minute Clip (Peak Orange): 87 MB/s @ 2.8k/14bits
Highest CropMood speed reached for "Continuous"  (Steady Green): 76.6 MB/s @ 2.8k/14bits
Highest CropMood speed reached for a 15 seconds clip (Red Speed): 88.9 MB/s @ 2.8k/14bits
240MHz / SDR104 (Benchmark is identical with SDR50)



Card has been formatted in camera (EOS M), moved to a Mac to copy the CropMood files, then back to the camera to make it bootable.


     

The testing method is outlined here: https://www.magiclantern.fm/forum/index.php?topic=25841.msg245694#msg245694


This time, I filled up the whole card's capacity with tests. This gave me more data: (The cam stops recording by itself)

30 Seconds: 87.6 MB/a
23 Seconds: 88.2 MB/s
18 Seconds: 88.6 MB/s
10 Seconds: 91 MB/s

The card is not as consistent as the Lexars in the red zone, but is very consistent in the Orange and Green Zones.
The performance is on par with the Sandisk Extreme Pro 256GB R200/W140, and costs 30% less even at regular price.
No Safe Mode triggers, no throttling, only a few sporadic "Frame Order" error messages (4 messages out of 90+ clips recorded), where the recording stops early.

Regarding the Benchmark:

The benchmark runs between 8-10 seconds and the number it gives is close to the 10 seconds results I got in the test. In this area, there is a lot of variability, except for the most expensive cards.
As discussed previously, a 1-2 MB/s difference can double the possible recording time at the higher end, and add up to several minutes in the low orange zone.

Most compatible "Pro" cards can perform reliably in the Green Zone (76-78 MB/s), but around this data rate, 1x3 4.4k/12bit and 1:1 2.5k/12bit are the highest settings where you'll get reliable recordings.

So, the most interesting zone to test is the Orange zone, where the cam can record continuously for 1 minute +. This is where the door opens to the highest resolutions.
1 minute is plenty to record about everything I see posted as examples on the facebook group...

Very few people will go through the trouble of testing the cards manually, and most people return the cards immediately if those don't work as expected. This makes it hard to know what can be done with a particular card, and those vary, sometimes substantially, between revisions.

So it would be nice if the Benchmark could test for SUSTAINED speeds for a given length of time,
which would make it a lot more useful and make it easier to build a reliable Card Database, as reporting would be simplified.

I use the Neutral 0,0,0,0 profile. I will add a note about it.

Thank you, full of useful information. However, you didn't mention that false colors are linked with the image profile and level of contrast used, so it's not accurate in RAW.

May I ask why you would want to change anything other than the sharpness in the picture profile? In RAW, it isn't recorded, so you would have no idea of what you are actually recording...

MOD: Please leave this post blank, as I will add more at a later date!

[Contents:]

This post will be very useful for anyone wanting to get the best image-quality-to-performance ratio, and newcomers who would rather make movies than spending countless hours browsing through too many posts. It may seem daunting at first and will probably require a few readings for some, but it will get you to the proper image quality level in a fraction of the time it would otherwise take you to absorb that much info.
I think that time can be better spent learning about proper lighting and exposure techniques than fighting with a camera for purely technical reasons!
So, here is a summary of everything I learned about ML for Eos M in the past 2 years.

Contents:

Where do those numbers come from?
1- Getting a proper SD Card.
2- Prepping the Card.
3- Using optimal Camera settings.
4- Optimal Scene Exposure Method (With False Colors examples).
5- Useful Links


Where do those numbers come from?

You can find an interactive version of the Data Rate Estimator here ;
You can read about the tests and procedure which lead to the above Estimator here (This has been written for a completely different purpose, but can still be very useful for those wanting to know more about the lossless compressor's efficiency);
You can read more about the way I tested some SD cards and detailed SD cards tests from this post onwards.

1- Getting a proper SD Card.

First, let's have a look at the Data Rate requirements for Lossless Raw Recording. Here is a Data Rate Estimation chart with a Lexar Silver Series 1066x 256GB Card, which is one of the fastest cards I have tested so far:

The numbers you see above are what you will get when exposing the image according to the method I will describe in Section 4. If you were to use the ettr (Expose as close to the clipping point as possible) method, those numbers would be even higher!
The Data Rate is highly dependant on scene complexity and brightness (More on this later). Therefore there are two numbers for each Bit Depth, for a particular preset:Normal and Complex.
The Normal number is the average Data Rate you will get for a scene with a moderate amount of details and some background blur, and the Complex number is the average Data Rate you will get for a scene with a lot of tiny details (Tree branches, blowing leaves, snow or tiny textures) and / or several reflective or shiny objects.
If you follow the guidelines explained later in this post, your Data Rate will be between those two numbers.

For example, you can see in the chart above that with a Lexar Silver Series 1066x 256GB Card, you can record comfortably (With less chances of the Camera stopping in the middle of a recording) at 1:1 2.5K 2.39:1 14bit (Data Rate between 69.4 and 81.2 MB/s) and lower; or 1x3 4.2K 16:9 12bit (Data Rate between 72.6 and 84.9 MB/s) or lower.
You could also record at 1:1 2.8k 2.39:1 12bit (Data Rate between 76.1 and 89.1) by exposing slightly below what is recommended. Underexposing by 1 stop reduces the Data Rate by 6-7%.

If you need to underexpose by 2 Stops  or more to get a low enough Data Rate, it is preferable to select the next lower bit depth (i.e. go from 14bit to 12bit).
I did a detailed test on that topic here.

The Lexar Silver Series 1066x 256GB Card is a very fast card capable of sustaining 88 MB/s for 1 minute or more and short bursts of up to 90.8 MB/s for 15 seconds. This is definitely not the case for the lower-end cards! (Those tend to yield inconsistent results when recording in the High Orange / Red Recording Indicator zone).
What the people on Youtube (Those who like to Hype things up) fail to disclose is that when they claim the camera can record continuously, it is often because they underexpose the image significantly, record very short clips or use the lower resolution and Aliasing-Prone 3x3 "1080p" mode. This is all fine if image quality is not your main concern, but definitely not if you want a clean image.

If someone recommends a Card saying "A lot of people said it works", ask them for a short clip and at which resolution they recorded. If you like what you see, then it is a good card for you!
The ML Benchmark fails to report certain subtleties that make a card suitable for longer recordings. There is no direct correlation between the numbers reported and the actual recording capabilities. Some cards just won't work despite showing good numbers! Therefore, I had to manually test a few cards to get a better idea of what's required. There is a list of tested cards in the Data Rate Estimator tool I linked above.

What I recommend is to get the fastest Card you can afford, otherwise, you will eventually have to buy another one...

Also, for applications where you just can't afford to redo a take (Weddings, some interviews, etc.) it would be wiser to use something like a Sony a6400. It will give you a sharper picture, full autofocus, ready-to-use files, better low-light performance and guaranteed recording times. In such cases, the less vibrant colors and banding issues are of lesser importance than the obligation not to miss a single moment!

The Eos M with ML will give you rich 12-14bit banding-free colors and the ability to deeply work those. You can modify white balance in post and apply LUTS to your footage with a lot less chances of getting a blocky image. But it requires more planning and is better suited for a "Scene-by-Scene" recording approach. Even if recording 30 minutes-long takes is possible, it is just not the way to go.

2- Prepping the Card.

Take the habit of doing a low-level format (Use the "Keep ML Files" option) before each filming session. For this, I will quote someting I said in a previous post:

I don't know about the magnitude of the speed gain when the blocks are pre-erased (format), but I know this:
Each time you insert the card in a different system, the file system is modified. The Mac writes a bunch of invisible dot files, Android writes extra folders both visible and invisible, etc.

After enough going back and forth (You need to transfer the files to your Mac or PC), the FAT gets corrupted (well, modified differently by a different OS, especially if you use the computer to erase the files)  and you slowly begin to get errors and corruptions, until the card needs a complete re-format and re-copying of all the files.

Ever since I started to Low-Level format before each recording session (There is a option to keep the ML files on the card. I don't know how they did it, but it works) I stopped having those kinds of problems. This is anecdotal of course, but I recorded about  7 TB over the course of the summer, most of it on the same 256GB card. So I guess this is a large enough sample.

3- Using optimal Camera settings.

For those who prefer using the higher resolution / high bit depth Presets, or just extend recording times, the following is recommended:
Kill Global Draw must be set to On;
ISO / Aperture assignments to the custom buttons must be avoided while recording. (On Danne's build, More Hacks must be set to "Allow" in the Customize Buttons section).
Also, it is preferable not to use shutter fine-tuning. You can find a very close match to the 180° rule by setting the shutter range to "Full range" in the ML menu, if what you get with the "Original" settings is too far off. I usually set it to 1/46 for 23.976 fps and it gives the expected motion blur.
You can read about the Data Rate impact of certain settings in this post.

To insure that the False Colors display correctly, use the Neutral Picture Style. You can change the sharpness, but not the other values. (I use 3,0,0,0). Those settings have no effect on the recording, but change the way the image appears in the Live View.


4- Optimal Scene Exposure Method.

Because Data Rate is Scene and Exposure (Brightness) dependant, it is important not to overexpose the image, if one seeks to use Higher Resolutions and Bit Depths. So, I did some tests to determine how to expose to maintain low noise levels and keep the Data Rates within the current Card's / Overclock capabilities. I did some preliminary testing from this post onwards.
The easiest way to reach an acceptable compromise is to use a combination of the False Colors and Histogram functions in ML.


By exposing the frame with the highlights showing mostly Yellow and only hints of Dark Red on the False Colors display, and by having the histogram (Which displays the rough average brightness of the frame) at 1.3 or below (The number is usually between 2.4 and 1.3 for 1:1 modes, mostly 2.0 when recording in 1x3 modes); you will reach the Data Rate figures found in the Data Rate Estimator Chart.

Here are a few examples where I recorded scenes with most of the frame in focus and plenty of details: (There are reflexions in the false colors images, as it was a sunny day)



2.8k 2.39:1 12bit, 87.07 MB/s. (The chart says 76.1-89.1 MB/s, we're quite close to the Complex number).



The same Scene, but 1 stop underexposed, 80.17 MB/s. (a reduction of 8% in Data Rate)



2.8k 2.39:1 12bit, 82.71 MB/s. (The chart says 76.1-89.1 MB/s, we're within range)



The same Scene, but 1 stop underexposed, 77.39 MB/s. (a reduction of 6.5% in Data Rate)



2.8k 2.39:1 12bit, 83.93 MB/s. (The chart says 76.1-89.1 MB/s, we're within range)



The same Scene, but 1 stop underexposed, 77.47 MB/s. (a reduction of 7.7% in Data Rate)



2.5k 2.39:1 14bit, 78.38 MB/s. (The chart says 69.4-81.2 MB/s, we're within range)
Here, I were able to push the clouds into the Bright Red Region, because there is very little of the frame in the highlights region (Yellow and above).



2.5k 2.39:1 14bit, 80.49 MB/s. (The chart says 69.4-81.2 MB/s, we're still within range, but close to the upper limit)
Here I pushed the clouds very close to clipping (Black spots in False colors). This needs to be avoided unless a large portion of the frame is well below the highlights region, otherwise the Data Rate will be too high. Note that the histogram is still below 1.3, this is why we are within range nonetheless.

The key is to have as little Red as possible in the false colors, just enough to keep as much of the frame as possible in the low-noise range.

When working with people, it is always better to use a Reflector or a powerful enough Led Light to avoid having to underexpose your talent because of a very bright environment.
Skin tones and the subject in the frame must be around the Orange False Color (Or higher) to be as clean as possible.

Here is an example of the noise level in the different False Colors areas when doing shadow recovery: (Click to see the animation)


There are some more Scene / Data Rate examples in this post;
And a primer on using False Colors here.

5- Useful Links.

Bilal's Crop Mood repository Link.
Danne's Custom Crop Mood repository Link.
Canon Eos M Manual Link.
ML Camera Help page (Useful for some functions) Link.

[Speed Test: Lexar Professional 1667x SDXC UHS-II 256GB]

Speed Test: Lexar Professional 1667x SDXC UHS-II 256GB
R250/W120
Product Number: LSD256CBNA1667 / A0185-V60-256BSL A (Written behind the Card)
MDT: 2020/12
PRV: 1.0

Highest CropMood speed reached for a 1 minute Clip (Peak Orange): 88.8 MB/s @ 2.8k/14bits
Highest CropMood speed reached for "Continuous"  (Steady Green): 78 MB/s @ 2.8k/14bits
Highest CropMood speed reached for a 15 seconds clip (Red Speed): 91 MB/s @ 2.8k/14bits
240MHz / SDR104



Card has been formatted in camera (EOS M), moved to a Mac to copy the CropMood files, then back to the camera to make it bootable.





The testing method is outlined here: https://www.magiclantern.fm/forum/index.php?topic=25841.msg245694#msg245694


This card did not exhibit any problems and was consistent. 
The card triggered a few "Frame Error" messages during the test.

This card has a high enough Data Rate to handle good brightness at 2.5k 14bits / 2.8k 12bits 1:1.

So far, I have noted that the difference in data rate between the camera stopping by itself at around 1 minute, and it going past the 2 minutes mark is often of 1-2 MB/s for most cards.

Unless you plan on recording clips at 3K 1:1/12bits (or Bright 2.8k 1:1), Samsung EVO Plus, Sandisk Extreme Pro and Lexar Silver 1066x are a better value, as this is one of the most expensive cards.

Micro SD vs SD card, both are the same.  Real shooting experience.

There is no way for us to replicate what you are seeing because you don't give any information, so it's not useful to anyone.  If you list what cards you use, in what conditions, people could check.

What happens with microSD cards is that not every SD adapter is created equal.
For example, the white samsung adapters make it easy to remove the microSD card, so it ends up moving a little sometimes and you get a faulty contact. With Lexar and some Sandisk, it is so tight that it is hard to remove the card from the adapter.
Usually, just removing the microSD card from the adapter and pushing it back in properly solves all problems.

Yes! But on the EOS M, the screenshot fumction only works to capture the ML Menus. Raw video needs to be turned off, so False colors and other overlays are not recorded.

I tried with both Bilal's (Raw video needs to be turned off manually) and Danne's (Raw video is turned off automatically) variants.

Screenshots: these now save in BMP format, not PPM.  This means...  you can view them just by opening the card.

It would be a good idea to eventually allow screenshots to also capture overlays. It would make taking examples in the field a lot easier, as holding a phone to take screenshots under the sun is not always convenient

Your results are in line with what I got when I tested mine here: https://www.magiclantern.fm/forum/index.php?msg=245718

Power up your camera in video mode.
Press MENU
Go to the last menu to the right -Custom Functions(C.Fn)-
Go to menu number 6 to the right.
Make sure the Trash button function is assigned to 0:Normal

Don't know what is causing this difference in benchmark results.

PS:
I haven't tested the card in Photo Mode because I don't know how to access the Crop Mood settings in that mode.

You access ML the same way, by holding the trash button a few seconds.
Try formatting your card in camera. Use the "Keep ML Files" option, restart.
In photo mode (Use the middle one, not the left most A) As soon as you start the benchmark, press the blue  play button. That's how the benchmark performs best.

The camera often records better after 1 or 2 recordings. Why? No one seems to know. But I didn't know this extended to the benchmark also. There is an option for "Card Warmup" but it is not necessary with the eos m. Just record for a few seconds once, then the subsequent recordings will be done at full speed.

@Zenny, If you want to avoid having a darker image than the camera can handle cleanly, you can use the false colors to help expose properly. This is not a Sony which can record cleanly at ISO 800! Have a look at this image (Click for the animation) The whole white portion was exposed so that it showed the corresponding False Color.

You see that at ISO 100, you can expose above Dark Grey (Charcoal) and have a relatively clean image, but as you bump up ISO, you must expose more to have a noise-free image.
At ISO 200, the noise starts being quite noticeable below Orange and at ISO 400, you need to be above Orange.
Looking at the images you posted, my guess is that most of the frame was exposed around the Cyan region, which is quite noisy.
To get the cleanest image possible, most of the frame should be exposed above the point where noise starts becoming noticeable.

Also, if you want small details like the tree branches in your images to come out sharp, you need to avoid using the 1x3 modes, as those make small details "Mushy".

@iaburn's advice is one to follow. If you need more light, you can use a tripod and use a slower shutter speed, so that you can keep the lenses at smaller apertures for more sharpness.

I did 2 posts on false colors / exposure vs noise here if you're interested:
https://www.magiclantern.fm/forum/index.php?msg=245760
https://www.magiclantern.fm/forum/index.php?msg=245761

Check built in console while program is crashing for hints.

WIll have to do more investigation on my end then.
How do I display the console?
Are you guys using the MLVApp version downloaded from the official site, or the runner on the GitHub page?(That one won't run on my machine, OS too old I think)
Could you try the pixel map I downloaded: https://bit.ly/4bKWy5C
(To make sure the error doesn't happen when downloading the file manually)

EDIT: It's because I downloaded the individual pixel map file manually. I just downloaded the whole MLVApp Code .zip file and got the pixel map from there. It works as expected now.
Maybe someone can have a look at the pixel file I downloaded individually (Linked above) to figure out what went wrong.

Here is the complete file: https://bit.ly/3wk4LNU
Thanks.

Hello, I tested Danne's magiclantern-crop_mood.2024Feb18_Custom.EOSM202.zip and ran into the following issue:
MLVApp 1.14, official build.
OSX 10.13.6

If I load a clip I just recorded using the new 1920x1080p preset, without the focus pixel map installed, the clip opens fine (With the focus dots showing).

If I shutdown MLV APP, Install the new 80000331_1992x1109.fpm; when I launch the app and open any 1920x1080p clip, I get a beach ball and I need to force-quit (I'm on OSX).

If I launch the app again, but load a 2.8k clip this time, all is well.

If I shutdown MLVApp, remove the 80000331_1992x1109.fpm file, relaunch and load a 1920x1080p Clip, the clip opens fine again.

In any case, as long as I load any previously recorded clip at a resolution other 1920x1080p, it works without a problem.

[The effects of different settings on Write Speeds / Recording times:]

Here's a test I made last week, checking overhead. Could be useful as a baseline.

The effects of different settings on Write Speeds / Recording times:

Because I didn't know what the parameters were ahead of time, I give the following figures in seconds of recording time instead of speed in MB/s.
This allowed me to set a fixed exposure level and only change Settings.
As the slightest change in exposure can make a difference of +- 30 seconds, this approach will make the test length more manageable, because there are too many variables to take into account to do several trials to check repeatability.

Card Tested: Samsung Evo Plus microSDXC UHS-I 512GB MB-MC512K (Fresh Low-Level Format)
Build Used:magiclantern-crop_mood.2024Feb11_Custom.EOSM202.zip
Resolution: 2880x1206 14 bit
More Hacks set to Always, unless specified.
Filming a test chart on LCD Screen, slightly off-focus to avoid moiré (Which would affect the Data Rate).

I set the exposure to be slightly under the Write Speed limit of the card,  so I could get a max record time of about 30 seconds (Baseline).

1- MF (Manual Focus), No Custom Buttons Assignments, Kill GD ON = 31-35 Seconds (Baseline)

2- AF (Auto Focus), No Custom Buttons Assignments, Kill GD ON = 31-45 Seconds

3- MF, No Custom Buttons Assignments, Kill GD Off = 20-21 Seconds

4- AF, No Custom Buttons Assignments, Kill GD Off = 20-21 Seconds

5-MF, Custom Buttons INFO x10 Zoom , SET False Colors, Kill GD On = 31-33 seconds

6-AF, Custom Buttons INFO x10 Zoom , SET False Colors, Kill GD On = 31-33 seconds

7-AF, Custom Buttons INFO x10 Zoom, SET False Colors, U/D ISO, Kill GD On = 6 seconds (31-33 seconds if More Hacks = Always)

8- MF, Custom Buttons INFO x10 Zoom, SET False Colors, U/D ISO, Kill GD On = 6 seconds (31-33 seconds if More Hacks = Always)

9-MF, Custom INFO Aperture Expo, SET False Colors, U/D ISO, Kill GD On= 6 Seconds (31-33 seconds if More Hacks = Always)

10-AF, Custom INFO Aperture Expo, SET False Colors, U/D ISO, Kill GD On= 6 Seconds (31-33 seconds if More Hacks = Always)

11-AF, Custom INFO x10 Zoom, SET False Colors, Kill GD On, Histogram On= 31 Seconds

12-AF, Custom INFO x10 Zoom, SET False Colors, Kill GD Off, Histogram On= 16-18 Seconds

13-AF, Custom INFO x10 Zoom, SET False Colors, Kill GD Off, Histogram On= 11-16  Seconds; Kill GD On=30-31 Seconds

14-AF, Custom INFO x10 Zoom, SET False Colors, Kill GD On,  =1:07 (I lowered the exposure to get a New, Longer Baseline)

14b-AF, Custom INFO x10 Zoom, SET False Colors, U/D ISO, Kill GD On,  = 6 Seconds

14c-AF, Custom INFO x10 Zoom, SET False Colors, Kill GD Off,  = 21-25 Seconds

Conclusion: For those who prefer using the higher resolution / high bit depth Presets, or just extend recording times, the following is recommended:
Kill Global Draw must be set to On;
and ISO / Aperture assignments to the custom buttons must be avoided while recording.

The map causing Mlv App to freeze? Works over here  .

Yes. If I load a clip recorded at any other resolution, everything is fine.
If I load a clip I just recorded at 1080p, without the focus pixel map installed, the clip opens fine (With the focus dots showing).
If I shutdown MLV APP, Install the new 80000331_1992x1109.fpm; when I launch the app and open a 1080p clip, I get a beach ball and I need to force-quit (I'm on OSX).
If I launch the app again, but load a 2.8k clip this time, all is well. MLVApp 1.14, official build.

[New build]

New build

- When Histogram and RAW-based is enabled 14bit preview whie in other bits is turned off working as regular 12,11,10bit preview. Fixes the histogram issue mentioned by @gabriielangel

Needs some testing.

@Frank7D, Yes, stretched, but only a little right? Maybe could be done better but I don´t know how.

The 1920x1080 preset needs a proper focus pixel map. The one I just downloaded makes my MLVApp freeze.
It records without corruption.
Preview is a little stretched, but as long as we know that it records fine (it does), we can at least see the full, uncropped preview.
It doesn't disturb me, as I use AF before recording, but someone who uses MF could chime in.

Note: Because we cannot skip the MLVApp Step no matter what, it would be wiser to record  using the 1440P preset and export to 1920x1080 with MLVApp. This gives sharper images (Oversampling) and the crop isn't as brutal.
The real reason to use the 1920x1080 preset would be to record 14-12bit Uncompressed (Which has been removed in this version).
When recording on a ski slope for example, this would prevent the camera from stopping the recording because of sudden variations in image brightness, which is likely to happen when recording at 14bit lossless.
It would also allow you, for example,  to clip the highlights a little to get more exposure for people's faces, as long as you know that if you clip too much, the pink highlights cannot be removed.

The histogram now works as before at all bit depths. I tried with both Kill Global Draw ON and OFF.
So, to make it clearer:
If you enable the Histogram, the Preview's Bit Depth is always the same as the recording Bit Depth selected (If you bump up ISO to 6400 and raise shutter to 1/1000 or more it is easy to verify.)

If Histogram is disabled, The Preview's bit Depth is always 14bit, regardless of the recording Bit Depth selected. The recording Bit Depth selected will kick in as soon as you hit record and will return to 14bit when you stop.
Especially when using 11-10bit, this gives an artifact-and-color-cast-free preview, which makes focus and evaluation a lot more enjoyable.

I will use it during the week and let you know if I find anything else.

Hello, The Histogram is broken at lower bit depths with the latest build magiclantern-crop_mood.2024Feb12_Custom.EOSM202.zip.

To reproduce the issue:

Load any 1:1 Preset (Because Histogram is steadier in this mode)
Set Histogram to RAW-based (RGB) / ETTR hint
Set the preset to 14bit
Aim the camera at something bright and steady (Lamp, LCD Screen)
Take a Histogram reading
Press Record
Take a Histogram Reading again, Everything is ok, the number is identical.
Set the preset to 12bit
Take a Histogram reading
Press Record
Take a Histogram Reading again, The Histogram number is now higher than it should.
The number will go progressively higher than normal as you select lower bit depths.

My guess is that the Histogram takes its reading after the Live View Brightening adjustment. Because you recently made it so everything stays 14bit until we hit record (...) fill in the blanks
Although it has always been off by about +-0.2 EV in the past when using 12,11 and 10bit, it was still close enough. Now the difference is such that it will display OVER, so we can't do the translation in our heads.

It was last seen working as before in Crop Mood 2024Jan08 Custom, and 2024Jan12 Custom releases (I don't have the others ATM).

BTW, the changes you've made in the Movie menu really make a positive difference, as everything is "Right There" (As opposed to the Jan08 and Jan12 versions I just tried).

[By how much can we reduce the Data Rate with Underexposure?]

By how much can we reduce the Data Rate with Underexposure?
Another chapter in the quest for Data Rate Optimization on Eos m.

Several people report long recording times on the various social media, but after close inspection, one sees that the footage is often severely underexposed.
So, how much gain (or rather, loss) can we expect, while keeping the quality as high as possible? See the attached animated .png below.

at 2.8k 1:1 14bit, The Data Rate can be reduced by 7%, by underexposing 1 Stop; and 13% by underexposing 2 stops (Will vary slightly depending on the scene being shot, of course).
Because the Bit Depth reduction is obtained by reducing the Analog Gain in the camera, Underexposing 2 stops equals switching to 12bit (3 Stops=11bit, 4 Stops=10bit).
BUT, as you can see in the image below, Underexposing is a lot noisier than reducing the bits with Analog Gain(!)
Therefore, as soon as you need to underexpose significantly, it is better to lower the Bit Depth to the closest match instead.

The color chart was lit by 2 LED panels, and was exposed so that the white square was right below the clipping point.
I recorded 1 clip per aperture, in 1/3 stop decrements. I then boosted the exposure accordingly in MLV App to normalize the smaller aperture clip's brightness against the first clip (Wide Open).
This clearly shows that the clip recorded at 12bit (12bit-ML) is cleaner than the clip recorded 2 stops underexposed (12bit-Equivalent). The same goes for 10 and 11bit at the transition points.
Also, the Data Rate is lower for the clips recorded with Analog Gain Bit Depth reduction (When you change the Bit Depth in the Movie / Crop Mood menus), because of the lower noise.
You can also see that at image 13, 4 Stops below, the noise is already quite apparent.

So, again, it would be a good idea to add a 13bit option, as this would allow a significant reduction of the Data Rate, while having almost no impact on image quality.
This would also give about 1 extra stop of cleaner exposure (Compared to underexposing by 1 Stop).
With a good card, it would be easier to reap the benefits of recording at higher Resolutions / Bit Depth / Exposures.
(Click on the image to load the full resolution animated version)




All the images in a .zip file, if you get dizzy: https://bit.ly/3SB7FoP

New build:
When up/down or SET or INFO buttons are assigned to ISO or Aperture More hacks is bypassed. If up/down button is disabled and other functions to SET and INFO are assigned than ISO and Aperture More hacks is active.

Could you elaborate a bit on the intended effect of adding More_harck Allow? If what's in the quote above is still active, I'm not sure what it targets exactly.

I Think Test 2 is better also, because we see the whole recorded frame (Some of the bottom was missing in the original preset). Test 1 is too small and could give the impression that something is broken.
In Test 2, there is a distortion at the bottom of the frame in the preview, but the image records cleanly.

About the Feb05 build additional tests, I tried the following settings at 2160x1620, 10 seconds clips, 5 trials each:

Manual Focus, Kill Global Draw On, 12bit
Manual Focus, Kill Global Draw Off, No Overlays, 12bit
Manual Focus, Kill Global Draw Off, Histogram On Screen, 12bit
Manual Focus, Kill Global Draw On, Histogram On, 12bit
Auto Focus, Kill Global Draw Off, Histogram On Screen, 12bit
Auto Focus, Kill Global Draw Off, Histogram On Screen, 14bit
Auto Focus, Kill Global Draw On, Histogram On, 14bit
Alternating AF/MF, Kill Global Draw On, Histogram On, 14bit for 6 trials

I got 1 corrupted frame on 1 out of 5 trials with Auto Focus, Kill Global Draw Off, Histogram On Screen, 12bit
No corrupted frames in any of the other trials.

Same Sandisk Extreme Pro 128GB R170W/W90 (Freshly Low-Level formatted)
Same button assignments as previously reported.
Files recorded @ 76MB/s (The cand can handle  76.5 in the Green)

I did not change focus, switch presets or used any of the custom buttons.

I updated my EOS M Data Rate Estimator Chart: Here
You need to save it locally or copy it to your google drive in order to use it properly.

No need to enter the numbers manually, you can now select one of the tested SD/micro SD cards using a Dropdown Menu.
Hopefully, more people will test their cards so that we can have a larger database.

What I have gathered so far is that, unless one plans on using only the 3x3 Modes, a card which can remain in the Green Zone at 76 MB/s or more
is required to be able to use most presets comfortably @23.976 fps. The higher resolution presets require one of the fastest cards.
It appears that some manufacturers have some cards run with a series of short "Bursts", so that those look good on benchmarks.
Although ok for file transfers, what we need here are steady sustained speeds! So, a different kind of benchmark is necessary.

If the quality of the image is important, 14 and 12 bit are to be preferred. At 12 bit, due to the way the bit depth is reduced,
we are already running almost 2 stops below optimal exposure. So trying to underexpose further to lower the data rate is not ideal (Would progressively make the image noisier).
I have seen a few posts on the facebook group where people are complaining about the noise, not knowing that recording at 10 bits is not ideal, and requires a very bright scene to look decent.
In such cases, choosing a faster card / higher bit depth is the best cure. This may all be obvious for most people on this forum, but it is definitely not so for someone first putting their hands on the cam!