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Long exposures with CMOS camera?

Posted: Thu Aug 03, 2017 8:30 pm
by abillionnewstars
Can I use Sharpcap for long exposure with a CMOS camera to image something like a nebula?

thanks

Re: Long exposures with CMOS camera?

Posted: Fri Aug 04, 2017 8:52 am
by admin
Hi,

it depends on the type (brand) of camera that you are planning on using. You need a camera that can do exposures of at least 1s, ideally up to 30s or more to capture galaxies and nebulae. Because CMOS cameras have lower read noise than CCD cameras it is possible to build up good images from lots of shorter (1s-60s) exposures in a way that wouldn't work with CCD cameras.

thanks,

Robin

Re: Long exposures with CMOS camera?

Posted: Fri Aug 04, 2017 12:14 pm
by abillionnewstars
I have the ASI1600MM-C in mind.
Can I go beyond 60s and cool it at the same time, save the subs (and why not) have live stacking at the same time. :D

thanks!

Re: Long exposures with CMOS camera?

Posted: Fri Aug 04, 2017 1:21 pm
by turfpit
Have a look at this http://www.astrokraai.nl/viewimages.php?id=266&cd=7. Done by the author of Autostakkert.

Dave

Re: Long exposures with CMOS camera?

Posted: Fri Aug 04, 2017 1:52 pm
by abillionnewstars
turfpit wrote: Fri Aug 04, 2017 1:21 pm Have a look at this http://www.astrokraai.nl/viewimages.php?id=266&cd=7. Done by the author of Autostakkert.

Dave
Thank you for this.
I suppose that was all done using SharpCap? He did this as he could not track well the DSOs. So that is an option.
My question remains: Can I do more than 60s with a 1600MM-C using SharpCap and can I cool it ( I don't see cooling modules in SC, so I doubt it)?

thanks

Re: Long exposures with CMOS camera?

Posted: Fri Aug 04, 2017 5:05 pm
by turfpit
Emil actually uses another capture program but that is irrelevant. The technique (capturing DSOs as SER files and stacking with Autostakkert) is important and will work on SharpCap. An alternate approach to having to worry about tracking - I will be giving this a try once I get some peltier camera cooling rigged up and if the clouds ever go away. See this CN post https://www.cloudynights.com/topic/5338 ... second-16/ . Emil is MvZ on the CN forum. That stunning image of M51 was the result of around 30 minutes of capture!

To answer your question, have a look at http://docs.sharpcap.co.uk/2.9/#ZWO%20Camera%20Controls , Thermal Control section. It is the manufacturer's SDK that provides the controls - SharpCap just exposes them to the user. I suppose the length of exposure is limited by how good the tracking/camera cooling is. See this Gary Palmer M31 done with SharpCap and 62 x 120s exposures https://twitter.com/Solar_Gaz?t=1&cn=Zm ... +272699405 . Having attended a couple of Gary's imaging workshops, it is highly likely that PixinSight was used to post-process this. The Altair Hypercam 183 which was used has an internal fan I believe.

Dave