Messages

1

Raw Video / Re: Canon 60D RAW Video

« on: July 09, 2022, 03:31:54 AM »

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.

2

Raw Video / Re: Canon 60D RAW Video

« on: July 07, 2022, 06:01:07 AM »

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.

3

Raw Video / Re: Canon 60D RAW Video

« on: July 07, 2022, 04:38:37 AM »

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.

4

Raw Video / Re: Canon 60D RAW Video

« on: July 07, 2022, 03:35:36 AM »

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. 

5

Raw Video / Re: Canon 60D RAW Video

« on: July 05, 2022, 01:10:33 PM »

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

6

Raw Video / Canon 60D RAW Video

« on: July 05, 2022, 10:33:31 AM »

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.