#1  
Old 03-05-2019, 09:50 PM
billdan's Avatar
billdan (Bill)
Registered User

billdan is offline
 
Join Date: Mar 2012
Location: Narangba, SE QLD
Posts: 1,320
Anyone tried Live Stacking with Sharpcap?

Sharpcap allows live stacking of subs which can be calibrated with a master dark and master flat on the fly.

I was thinking this would be good for lucky imaging, instead of saving 100's of ASI-1600 short exposure subs, just stack them all as they come in. Just have to run the risk that no sat trails are stacked as well.
Reply With Quote
  #2  
Old 03-05-2019, 10:15 PM
Camelopardalis's Avatar
Camelopardalis (Dunk)
Drifting from the pole

Camelopardalis is offline
 
Join Date: Feb 2013
Location: Brisbane
Posts: 4,637
Bill, I’ve used it a few times for hits and giggles from here in the city, but don’t trust anything that works that quickly to calibrate and restack the frames precisely

It takes a lot longer to do the same thing in PixInsight with 4 cpus blazing...just saying
Reply With Quote
  #3  
Old 03-05-2019, 11:33 PM
Hemi
Registered User

Hemi is offline
 
Join Date: Dec 2010
Location: Darwin
Posts: 261
Iíve done a bit of it...near real time imaging, with live stacking in sharp cap. Itís a lot of fun. I posted some pics in the beginners section recently. There are lots of threads about it on cloudy, in the EAA section.

You can use darks, flats and bias calibration frames on the fly with each sub. Iím in the process of making a library of calibration frames, but havenít used them in my stacks so far. The amazing thing is it works well for near real time, without the calibration frames.

There are people doing live webcasts on nightskiesnetwork, showing how they do it.

Cheers

Hemi
Reply With Quote
  #4  
Old 04-05-2019, 08:20 AM
billdan's Avatar
billdan (Bill)
Registered User

billdan is offline
 
Join Date: Mar 2012
Location: Narangba, SE QLD
Posts: 1,320
Thanks guys, sounds like you both have had a lot of fun with it.

Does it have any rejection algorithms, like can it recognise satellite trails or aircraft? If you could set a FWHM size would be good to, so it can reject subs with fat stars.
If it did have these, this process could revolutionise astrophotography into the future. Especially now with low noise CMOS cameras allowing shorter subs than CCD's. As the saying goes its the total integration time that counts not the sub length.

EDIT: Hemi, I just had a look at the images you posted and they came out not too bad, darks (and/or dither) will eliminate the hot pixels, and flats will eliminate the bright spot in the centre. You also answered my question about FWHM as well.
If you have Startools, don't do any stretching or white balance in Sharpcap (must be saved as a FITS file), let Startools do it all.

Last edited by billdan; 04-05-2019 at 08:47 AM.
Reply With Quote
  #5  
Old 04-05-2019, 09:14 AM
ChrisV's Avatar
ChrisV (Chris)
Registered User

ChrisV is offline
 
Join Date: Aug 2015
Location: Sydney
Posts: 1,223
Been doing it for a few years - only for live imaging. Short subs (2-10sec) at highish gain. It's fun watching the image emerge and you can bang through a dozen targets in an hour or so. The more recent introduction of correcting with darks and flats makes it so much prettier. You can set rejection levels for individual subs but I never bothered with that.
Reply With Quote
  #6  
Old 04-05-2019, 10:04 AM
Camelopardalis's Avatar
Camelopardalis (Dunk)
Drifting from the pole

Camelopardalis is offline
 
Join Date: Feb 2013
Location: Brisbane
Posts: 4,637
Yeah you can apply FWHM filters and there are(simple) controls over the pixel rejection.

It can be quite effective with short exposures, especially from light affected areas such as here in the city.
Reply With Quote
  #7  
Old 08-05-2019, 06:44 AM
tvandoore (Tim)
Registered User

tvandoore is offline
 
Join Date: May 2016
Location: Buderim
Posts: 35
Good for showing kids/visitors that my space pictures really do come from my equipment and not the internet.
Reply With Quote
  #8  
Old 08-05-2019, 01:11 PM
billdan's Avatar
billdan (Bill)
Registered User

billdan is offline
 
Join Date: Mar 2012
Location: Narangba, SE QLD
Posts: 1,320
Here is a link to Cloudy Nights of lucky imaging in luminance of M51 doing 5 sec subs.
I quote
An ASI1600MM Pro CMOS camera was used for both image capture and guiding. The luminance image was computed using ~ 50 10 minute subs. Each sub was the average of up to 120 5 second exposures.

https://www.cloudynights.com/topic/6...y-imaging-m51/

Interesting he uses the one camera for imaging and guiding, however he did write his own guiding software (on a Mac) to do this..
Reply With Quote
  #9  
Old 09-05-2019, 04:36 PM
Star Catcher (Ted Dobosz)
Registered User

Star Catcher is offline
 
Join Date: Feb 2006
Location: Bankstown
Posts: 945
The live stacking works a treat for shortish or long exposures. The flat and dark calibration works well on the fly but I have not done any stacking shorter than 15 seconds nor any longer than 10 minutes using an ASI294MC pro.

Ted
Reply With Quote
  #10  
Old 09-05-2019, 08:49 PM
AstroJunk's Avatar
AstroJunk (Jonathan)
Shadow Chaser

AstroJunk is online now
 
Join Date: Jan 2006
Location: Brisbane
Posts: 1,676
I'm using it right now - Good fun, and as I only take 'Happy snaps' it works well for me
Attached Thumbnails
Click for full-size image (eta-snip.jpg)
197.2 KB39 views
Reply With Quote
  #11  
Old 10-05-2019, 07:41 AM
billdan's Avatar
billdan (Bill)
Registered User

billdan is offline
 
Join Date: Mar 2012
Location: Narangba, SE QLD
Posts: 1,320
ETA C looks really good Jonathan and it appears you are using just over 1 sec exposures.
On the bottom it shows you stacked 32,511 frames and discarded 44 frames. Imagine the disk space required if you had to save each individual frame and stack separately.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 06:47 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement
NexDome Observatories
Advertisement
SkyWatcher Australia
Advertisement
OzScopes Authorised Dealer
Advertisement
Celestron Australia
Advertisement
Lunatico Astronomical
Advertisement
Meade Australia
Advertisement
Astronomy and Electronics Centre
Advertisement