Levas' crop_rec_4k experiments for 6D

[Levas]

The preview is indeed very slow, unfortunately I don't have the knowledge to fiddle with the preview options in source code.
I made the custom resolutions for crop recording on the 6d, so learned a lot about the crop_rec module, but the rest of magic lantern source is like magic to me 

Canon liveview is broken in 4896x2160 crop rec option.
You could however use the 5496/3x1960 at 24 fps option in crop_rec menu.
5496/3x1960 has canon liveview working (although a bit squeezed and zoomed in)
Depending on your 'preview' setting in the submenu of raw recording, you could switch from Canon liveview to slow correct preview with half shutter (works while recording)

The way I would use it:
Use 5496/3x1960 at 24 fps in crop_rec menu.
Go to RAW video submenu (use Q button on RAW video in the MOVIE tab in ML menu.
Set resolution lower to get desired resolution/aspect ratio, you can use scroll wheel on top of your DSLR to set it (for example) from 1824x1960 to 1568x1960 to get 4704x1960 at 24 fps (2.4:1 aspect ratio).
Now go to preview option and set it to 'real-time'.
Now exit menu and you will see some distorted canon liveview which is as fast as Canon liveview, although not correctly framed, but if you do half press the shutter button, the correct framing preview shows up 
So use half shutter to get framing right, release half shutter to set focus right and keep track of your subject. While recording, you can check framing by using half shutter press.
So that's the most usable way I found, using real-time preview and occasionally using half shutter press to check framing.

[zezic]

You could however use the 5496/3x1960 at 24 fps option in crop_rec menu.

Oh, it works! This squashed view is totally fine for me. But, I got data corruption to often. It's almost impossible to get even a few seconds of clean recording without data corruption at 1960px vertical resolution. The 1872px vertical resolution is more stable, but data corruption is also happens sometimes, you can notice few flickers: https://youtu.be/pKkrqyrQykA (sorry, handheld shaky video).
Can you suggest something to lower the chance of the data corruptions? The benchmark shows that my card is able to do ~90MB/s (with 240MHz overclock, of course).

[Levas]

Corrupted frames is not good   
Made a new crop_rec module where the max vertical resolution is lowered by 16 pixels. (So 16 lines less to read out by the sensor)

5496/3x1944 @ 24 fps
5496/3x1856 @ 25 fps

I expect this should prevent corrupted frames. Could be that it's still a little too much.
If you still experience corrupted frames, let me know, then I make a crop_rec build with the vertical resolution slightly more lower till no more frames are corrupted.

The crop_rec.mo file can be downloaded here from my google drive. you can replace this crop_rec.mo file with the crop_rec.mo file on you sd card (location on SD card:  ML/MODULES/ )
https://drive.google.com/file/d/14Rff7xmEOOVF9nxSFRYYVyKutGqhYS-D/view?usp=sharing

[zezic]

Corrupted frames is not good   
Made a new crop_rec module where the max vertical resolution is lowered by 16 pixels. (So 16 lines less to read out by the sensor)

5496/3x1944 @ 24 fps
5496/3x1856 @ 25 fps

I expect this should prevent corrupted frames.

Looks like it fixed the issue. I was able to record this ~1 minute example at 5496/3x1944 @ 24 FPS : https://www.youtube.com/watch?v=ePmpH5QNuGU
Thank you! I'm very happy, going to post more tests with steadicam soon.
By the way, do you have a repository at GitHub or other Git hosting where it's possible to see the edits you made to the source code?

UPD: Another quick test, now with steadicam: https://youtu.be/Lrc_npKrWaQ

[Levas]

Good to hear it’s working without corrupted frames 
I don’t have the source online.
But I could upload it to my google drive.
It’s mostly the crop_rec module where changes are made.

The steadycam footage looks good on youtube in 4k 

[lightwriter]

Looks like it fixed the issue. I was able to record this ~1 minute example at 5496/3x1944 @ 24 FPS : https://www.youtube.com/watch?v=ePmpH5QNuGU
Thank you! I'm very happy, going to post more tests with steadicam soon.
By the way, do you have a repository at GitHub or other Git hosting where it's possible to see the edits you made to the source code?

UPD: Another quick test, now with steadicam: https://youtu.be/Lrc_npKrWaQ

Is the steadycam a real steadycam or a stabilized lens? Looks amazing, by the way!

P.S.: I can buy a 6D with 190.000 actuations for €180 euros. I know the MTBF is 150.000. What do you think about this? Should I go for it? Right now I have the EF 35mm f/2 (the non stabilized version).

[zezic]

Is the steadycam a real steadycam or a stabilized lens? Looks amazing, by the way!

Thanks! It's a real steadycam, the model is Glidecam HD-2000, I'm not very good at it yet, just started practicing. The lens is Helios 40-2-C 85mm (dumb metal+glass, no electronics). The lens combined with 6D and this steadycam make the whole setup a heavy thing, but I like it!

P.S.: I can buy a 6D with 190.000 actuations for €180 euros. I know the MTBF is 150.000. What do you think about this? Should I go for it? Right now I have the EF 35mm f/2 (the non stabilized version).

Probably, it can be a good setup for recording some static shots and maybe even some scenes with slow careful panning without stabilization (the shake is less noticeable on 35mm than on 85mm, but you have to try it yourself to check if you can hold it steady in your hands). What's about shutter live span – honestly, I don't even know how to estimate it, I bought mine 6D with ~23k shutter count so I'm not worrying about it at all. The 190k shutter count can turn out to be a lottery and maybe it's not that important for video, however, I'm not sure that 6D is the best option for RAW videos at its own.

[anto]

Corrupted frames is not good   
Made a new crop_rec module where the max vertical resolution is lowered by 16 pixels. (So 16 lines less to read out by the sensor)

5496/3x1944 @ 24 fps
5496/3x1856 @ 25 fps

like 5k anamorphic on the eos M? there is a real time preview?

[Levas]

No realtime correct framing liveview.
There is realtime liveview, but it is squeezed and zoomed in.
So to check framing, you need ML preview (the preview with slow refresh rate)

[Levas]

For those interested:
Posted some comparison shots 6D to R5 and posted them in the R5 topic.

https://www.magiclantern.fm/forum/index.php?topic=24827.msg239189#msg239189

[Sténo]

I was wondering where is the ettr module in this version

where can we find it on the site to install it?

[orcslayer]

Any idea what is causing flickering effect in some of my videos? Same effect during camera preview - 1X1 pixel binning 3072x1152@25fps[magiclantern-Nightly.2020Jul16.6D116] 7 out of 37 videos have this flickering effect going on.

[Levas]

The build is based on the same branch as the ML build on the download page on magiclantern.fm -> experiments -> 4K raw video recording; lossless compression

https://builds.magiclantern.fm/jenkins/job/crop_rec_4k/80/artifact/platform/6D.116/magiclantern-crop_rec_4k.2018Jul22.6D116.zip

That build contains a ettr module, see folder 'ML/modules/ettr.mo', you can copy the ettr.mo file to the build on your card in the same folder as the other modules, should work.

Haven't used the ettr module myself, so not sure how good it works, I'm using raw histogram and adjust exposure to that.