Canon 60D RAW Video

Started by nzpeterb, July 05, 2022, 10:33:31 AM

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nzpeterb

Hi all,

I have a Canon 60D I use with a telescope for recording 3 minute videos of Jupiter and 7.5 minute videos of Saturn.
Using the 640 x 480 video crop mode I get videos with 50 frames/second, so a 3 minute video is 9000 frames.
I then convert the video from MOV to AVI and stack the best half of the 9000 frames into a single image using dedicated software to get a single image of the planet.

I was reading that the Canon MOV file is compressed so have downloaded ML to see if the quality will improve if I start with an uncompressed video.
Magic Lantern is working and I see it has useful features like chip temperature, but I cannot get the software to save anything other than MOV files.

Can I get some direction please to save a RAW MLV video instead of an MOV file. The only quality setting I can see is changing QScale.
There does not appear to be any setting in ML for RAW video.

Thanks in advance.

Peter.

Walter Schulz

https://wiki.magiclantern.fm/faq -> Usage -> 3rd
The module you need is mlv_rec.mo
To avoid aliasing I recommend to use crop mode 1:1.

nzpeterb

Thank you Walter,

I was looking on the first menu screen that doesn't show the module option, but got that and the reply module sorted now. 

I understand the 60D write speed to the card is limited to between 21 and 25 MB/sec dependent on the information source.
Setting the camera to 640 x 480 crop mode in the Canon menu which uses just the centre of the chip, I then used ML to set the video mode and had to use 640 x 320 pixels for an aspect ratio of 2:1 to get the write speed down to 21 MB/sec. This was with a shutter speed of 1/64 sec as this was the lowest speed I could set.
Does this sound right, or do I need to implement another module to drop the video shutter speed to say 1/50 sec, which would allow the video size to be increased?

Regards,

Peter

Skinny

if you have crop_rec module for 60D, use it.
try usual 24 or 30fps 1080p in canon menu, you don't need to change it.
then press zoom x5 and check if you have good resolution in crop mode, you should be able to record more than full-hd resolution (around 2,5k) and it will be cropped from the center of the frame, 1:1 pixels.

so obviously such high resolution is a lot of mb/s, go to FPS override, and lower the fps (select lo-light setting there). somewhere around 3-4 fps you will be able to record continuous with 21mb/s.
then go to expo tab, select "exposure override" and now you can use very long exposures, up to the frame rate (1/3 second or what you selected).

then you will end up with MLV files on SD card, use MLV App to develop them or to export them as dng files to use in another program.

p.s. when using fps override at slow settings the UI will become also very slow, so it is easier to set other parameters (as well as focusing) before enabling it. And when you go to low fps - picture becomes brigther because now you use long exposures, so you can probably drop the ISO to 100, so less noise.

you can also make a dark frame with MLV App and apply it there.

nzpeterb

Skinny,

Thank you for the reply. I have been reading the forum and various support documents, then trying different settings on the camera.
There does not appear to be a crop_rec module for the 60D.

For anyone interested I thought I should write about what I want to use the ML software for, as it is likely not your normal application.
Because of the instability of the atmosphere when capturing video of the solar system planets the aim is to have the fastest shutter speed possible to try and capture frames during fleeting moments of good seeing.
Higher ISO's are needed as the scope/lens is 3600 mm focal length and f24. I normally capture video at ISO 3200 or 6400.
Due to the rotation of the planets being photographed the videos are maximum 3 minutes for Jupiter, but 7.5 minutes for other planets.
Based on quality the best 25% to 50% of the video frames are then stacked into a single image.
With the ISO's I am using the noise is too great is less than the best 2,000 frames are stacked.
The stacking software is sophisticated as it breaks the frames into pieces to stack the best frames of different planet features, then reassembles the stacked result back into a single frame. 

With the original Canon software I get a 640 x 480 pixel H.264 compressed video (MOV file) at 1:1 scale (not down sampled). This is captured at 50 frames per second, so 9,000 frames in 3 minutes.

With Magic Lantern I can get a 640 x 640 pixel RAW video (MLV file) captured at 30 frames per second, so 5,400 frames in 3 minutes. This is achieved using 5x zoom and gives the same image scale as the Canon crop mode. Any time I get the frame rate up (by deliberately underexposing the video) the higher frame rate exceeds the write speed to the SD card.

So assuming I have the ML settings optimised the question is whether stacking 50% of 5,400 RAW frames to create a single image will be better quality than stacking 50% of 9,000 compressed frames. Unfortunately the weather here is forecast to be poor in the next couple of weeks so it may be a while before I have an answer.

Thanks again to the ML team for making the software available and for responding to my questions.

Regards,

Peter. 



names_are_hard

This is lucky imaging, yes?  Raw image quality will be quite a bit higher, but if you have to lower fps to 30 you may get more atmospheric disturbance.  I think you'll have to try it and see.

If you can upgrade to a 650d you should be able to do 640x640 at 50fps.  With lossless compression 800 something, with SD overclocking perhaps as high as 1280x1280 60fps.  I am sure the 650d would be much less than your scope and mount, plus you'd get some back if you sell the 60d.

nzpeterb

Yes, this is lucky imaging.
I did find the table of camera capabilities on the site and agree a 650D should allow an increase in frame rate.
For anyone looking for this information it is in the forums here: https://www.magiclantern.fm/forum/index.php?topic=6215.0

I have had the 60D a few years and it was specifically purchased as I use my scope, camera, and mount without a computer tethered.
The 60D is one of the few models Canon provide with the 640 x 480 1:1 crop mode.
However using ML would allow 1:! crop mode with a range of cameras such as the 650D with an increased write speed and therefore frame rate, so this is an option I will look into after these initial tests.

Regards,

Peter.

nzpeterb

Sorry, another question.
I started looking at the 650D in the table referenced in my last post.

Then I found another calculator at https://www.magiclantern.fm/forum/index.php?topic=14909.0
When I open this it shows none of the cameras can record at 50 fps with 1 x 1 sub sampling.
If this calculator obsolete, or is 30 fps the maximum achievable without down sampling?

Regards,

Peter.

Skinny

It's just an old information.. this is what you will get with 650D or 700D: https://www.magiclantern.fm/forum/index.php?topic=25784
And Bilal is also working on 100D, I wonder if 100D have less sensor noise than 650D

What about 5D3? it is full-frame camera so no 1.6x "magnification" but it will probably have much lower noise with high iso..


heder

Hi Peter

Your goal is to get maximum of 9000 frames in 3 minuttes, but perhaps it is'nt your real goal. You are currently "stuck" in 640x480, but perhaps its time to free your mind :), ML can do other aspect ratio that be be used to get more than 9000 frames in 3 minuttes. There is a calculator out there to guide you :  https://rawcalculator.netlify.app/calculator_desktop  This calculator says the 60D has a 285 MB buffer, 21 MB write speed and max 60 fps (CROP MODE), the calculator is not 100% precise but its good. So what is the max fps you can get in 3 minuttes ?. That is the fps were you utilize the entire buffers before the camera memory is full and the camers stops, after presicely 3 minuttes.

Set

  • the resolution to 640
  • aspect ratio 4:3
  • crop mode
  • 43 fps (custom)
You will see that the max recording time is 4 minuttes and 45 seconds.  In three minuttes you'll get 43*3*60 = 7740 frames.

Set

  • the resolution to 640
  • aspect ratio 1.85:1 (640x346)
  • crop mode
  • 60 fps (custom)
You will see that the max recording time is 3 minuttes and 57 seconds.  In three minuttes you'll get 60*3*60 = 10800 frames.

But the real format is the one that fits the planet or object that you need to capture. Clear Skies !

(And accordingly to the https://docs.google.com/spreadsheets/d/16cgnRivbUv7nA9PUlCLmLdir3gXdIN3pqzCNAAybepc/edit#gid=3 60D should be capable of going up to 60 fps in CROP mode)
... some text here ..

nzpeterb

Thanks for the replies.
I will have a look at frame rates and aspect ratios to get the frame rate up 60 fps.
The 1.85:1 option will work as Jupiter (the largest of the solar system items as viewed from earth) is only 80 pixels diameter.
Due to the long focal lengths used this does require the tracking mount to be well set up and aligned.
Testing I have done also shows image brightness will affect the frame rates achieved.
That is, a darker exposure (less data) results in a higher frame rate.

Thanks again for everyone's help, Just waiting for a clear night to try the various options.

Regards,

Peter.