All Sky settings

Using SharpCap for other Astro Imaging such as all sky cameras and meteor detection
dfisherows
Posts: 12
Joined: Fri Jun 09, 2017 4:39 pm

Re: All Sky settings

Post by dfisherows » Sun Oct 01, 2017 1:46 pm

Here is a link to the video on my YouTube channel. Ignoring the title the video is 23 secs long. Each raw video was 3-4 secs in length and I can't figure out why.

https://youtu.be/hIjBtXqbKAw

User avatar
admin
Site Admin
Posts: 733
Joined: Sat Feb 11, 2017 3:52 pm
Location: Vale of the White Horse, UK
Contact:

Re: All Sky settings

Post by admin » Sun Oct 01, 2017 2:57 pm

Ah, that makes sense - SharpCap sets a frame rate of 30fps on the created AVI file (regardless of the actual frame rate or exposure time). This is usually a good value as you really wouldn't want to be waiting 30s for each frame to change if it set the true frame rate for your exposure times and it means you have a good chance of seeing detail in frames if you are capturing at very high rates.

You should be able to change the frame rate of the saved file using something like the "AVI Frame Rate Changer Tool" described here - https://superuser.com/questions/45250/f ... f-avi-file (note - I've not used this tool, but it sounds like it would do the job).

Robin

dfisherows
Posts: 12
Joined: Fri Jun 09, 2017 4:39 pm

Re: All Sky settings

Post by dfisherows » Sun Oct 01, 2017 4:58 pm

Thanks for the info Robin.

User avatar
turfpit
Posts: 92
Joined: Mon Feb 13, 2017 8:13 pm
Location: UK
Contact:

Re: All Sky settings

Post by turfpit » Sun Oct 01, 2017 7:02 pm

I will try this out tomorrow on the bench with an ASI120MC and see what happens.

Dave

dfisherows
Posts: 12
Joined: Fri Jun 09, 2017 4:39 pm

Re: All Sky settings

Post by dfisherows » Mon Oct 02, 2017 5:38 pm

Will keep trying the AVI, but until then here is an example of a time lapse of the night sky using Sharp Cap and a ZWO ASI120MM-S using the PNG setting. Approx. 1250 images. Link is below.

https://youtu.be/APs_IzVlfPY

User avatar
admin
Site Admin
Posts: 733
Joined: Sat Feb 11, 2017 3:52 pm
Location: Vale of the White Horse, UK
Contact:

Re: All Sky settings

Post by admin » Mon Oct 02, 2017 5:49 pm

Nice video :)

Just had a look, and it looks like PIPP (https://sites.google.com/site/astropipp/) can change frame rates when re-saving as AVI. You could also experiment with saving as SER (which has a timestamp for every frame) and then processing to AVI in PIPP.

cheers,

Robin

User avatar
turfpit
Posts: 92
Joined: Mon Feb 13, 2017 8:13 pm
Location: UK
Contact:

Re: All Sky settings

Post by turfpit » Tue Oct 03, 2017 9:20 am

David

I had a look at this as a limited test but enough to document what is happening. I think Robin will be able to expand on this. What I can say is that the capture settings you used are being interpreted by SharpCap as we expect.

The tests were carried out on the bench using an ASI120MC with wide angle lens, set at 1280 x 960 (maximum) with an exposure time of 30s.

1st test
A straight 60s capture. 30s exposure for 60s should give us 2 frames. When loaded into Autostakkert, the software reported 2 frames were loaded.

These were the settings used for the extended captures.
capture-settings.PNG
capture-settings.PNG (13.62 KiB) Viewed 49 times

So the expectation is using a 30s exposure - capture for 10 minutes (should result in 20 frames per capture), 6 captures (should result in 6 files).

These are the results:

AVI capture
AVI-files.PNG
AVI-files.PNG (26.46 KiB) Viewed 49 times
6 files as expected. The Length column of 00:00:00 - not too sure what that means.

AVI-in-PIPP.PNG
AVI-in-PIPP.PNG (19.62 KiB) Viewed 49 times
20 frames indicated but the fps is shown as 30. I think Robin has commented on this above.


SER Capture
SER-files.PNG
SER-files.PNG (27.46 KiB) Viewed 49 times
6 files as expected.

SER-in-PIPP.PNG
SER-in-PIPP.PNG (18.62 KiB) Viewed 49 times
20 frames indicated with a fps of 0.03. 0.03 multiplied by 600 (10 minutes) gives 18 frames - so about right.

Note the files sizes for both AVI and SER are around the same. When both types of files were loaded into Autostakkert, the software report 20 frames.

There seem to be lots of anomalies thrown up on forums concerning AVI files - a particular one being a size limit of 2Gb (sometimes). Also, historically, there seem to be different 'standards'.

The SER format seems much better defined and would certainly be a good choice for high speed planetary imaging where large files are produced. I always use SER now for video capture as with PIPP there are plenty of conversion options available. The SER Player is also useful as it reports file properties and shows a histogram if that option is switched on.

Hopefully this will help clarify what is happening (even if it doesn't fully answer your question) and demonstrate that SharpCap is working reliably.

Dave

dfisherows
Posts: 12
Joined: Fri Jun 09, 2017 4:39 pm

Re: All Sky settings

Post by dfisherows » Sat Oct 21, 2017 5:55 am

Thanks for all the info/help. Doing fine now that I understand it.

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest