Video for Stacking- How Much is Too Much?

[xa-coupe]

I took a mammoth (73gb) video of Jupiter last night and to be frank, the quality of the resultant picture didn't seem to be hugely better than a 14gb file.


Is there a point of diminishing return with the size of videos being used for stacking?



Using Firecapture, Autostakkert! and RegiStax..

[Merlin66]

Jeff,
My example is solar imaging....
If you use say AS3! For quality assessment and stacking. What is does is analyse the total video for the best quality image and then matching the rest of the frames to that. If there’s no movement - rotation etc then each frame will effectively have the same basic data. In this case the final stack should reflect the best quality outcome.
If, like me in solar, there’s dynamic movement across ALL the frames (think about prominences changing over the duration of the video) a long AVI video is a bad choice! The stacking program will attempt to stack the best frames which may be subject to movements.
It’s much better to run a series of shorter AVI to get the best quality result with minimal movement. Processing each AVI and then if appropriate stacking the final images.
It may well be that the rotation of the planet in aggravating the quality of the stack. You could use Vdub to cut the large video into smaller AVI’s and see if there’s any improvement.
Summary: large AVI files are not the best solution.

[xa-coupe]

Thanks Ken .. makes sense. I'll have another bash later tonight when Jupiter and Saturn clear the roof, I will keep the videos relatively short.

[iborg]

Hi

Jupiter does rotate fast - so de-rotate the video!

See https://www.skyatnightmagazine.com/astrophotography/astrophoto-tips/use-winjupos-derotate-planetary-images/

One of the many things I haven't yet tried.

Good luck

Philip

[xa-coupe]

Thanks Philip ... I see that they recommend 1 minute per video ... err.. I have none even close to that small. Good thing tonight is another night. I will have a go at many small ones and see how it works out.
Winjupos definitely has possibilities ....

[Camelopardalis]

I typically capture in 30 second spurts, but it really depends on your pixel size and scope focal length as to what time period is best to not see rotation in one of your captures.

But yeah, you'll need to get up close and personal with WinJUPOS. It's not all that time consuming once you get the hang of it, and you can usually tell whether the data is any good or not from a single sequence stack (i.e. if it's blurry, move on to the next one ;) )