Time lapse capture with live view at same time

[mconsidine]

Hi,
Apologies in advance if this is suggested or covered in a how-to elsewhere. I've searched the forum as well as Google and not hitting on anything.

I'm interested in trying to find out how I can create a time lapse video while maintaining the ~live display. I was able to do this in Firecapture with its TimeLapse button and figured something similar should be available here.

The video would be, say, 1 hour long with half-second exposures (or even bursts of exposures) every 5 minutes. The result ending up in a SER or AVI file.

The use case is the following: a colleague has a coronagraph with a very good mount. But the solar disc needs to stay behind the occulting cone/disc as much as possible and with the high resolution of the instrument it is easy for wind or gear errors to knock things around, requiring a manual adjustment to the guiding/positioning of the scope. So having the "live" view going at the same time as the much less frequent video creation would be extremely helpful.

I found one other post from a number of years ago that seemed to be a similar request, but it didn't seem possible at the time. Has anything changed? Is it possible to do this now or should this be considered a feature request?

Much obliged for any help!
Regards,
mconsidine
PS: Admin - if this post should be in a different part of the forum and it could be moved, I'd appreciate it.

[admin]

Hi,

the only simple thing I can think of is to use the 'frame rate limit' control, but that affects the display as well as what is saved to file. For example you could set exposure to 0.5s and the frame rate limit to 1 every 5 seconds. If you record for an hour you will get 720 frames about 5 seconds apart, and the display will update once every 5 seconds too.

You could also set up something like the timed sequencing to capture one frame every 10 seconds with the exposures set to 0.5s. You would then get 360 still frames over 1 hour which you could convert to a video with some other tool.

cheers,

Robin

[Jean-Francois]

Hello Matt,

If I understand correctly ... you want to have an animation with for example 13 single images taken during 1 hour ... one image every 5 minutes.

I'm sure that you can write a script for that ... here a beginning ...

Code: Select all

SharpCap.SelectedCamera.PrepareToCapture()
SharpCap.SelectedCamera.RunCapture()

Here a loop ...   
    time.sleep(t1)
    SharpCap.SelectedCamera.Paused = True
    time.sleep(t2)
    SharpCap.SelectedCamera.Paused = False
    
SharpCap.SelectedCamera.StopCapture()
    

With t1 = time of image capture and t2 = time until next capture.
You can pause and resume a capture with the function "SharpCap.SelectedCamera.Paused".

The script should be more elaborated:
- allow user time selection
- error handling
- allow to quit the loop before end of the sequence
- ....

Regards,
Jean-Francois

[mconsidine]

The key is to have the live view active while the saving of images is taking place into a video, the latter happening at a fairly long interval.

That way, the observer can focus on other things, like nudging the scope to keep the sun behind the occulter.

Hope that makes sense!
Cheers,
Matt

[admin]

That's a good suggestion from Jean-Francois... The pause function being turned on and off automatically would do the trick nicely as it leaves the live video active and suspends/resumes the writing of frames to file. Currently this would need to be done via the python scripting though.

cheers,

Robin