Longer, colder subs?

[rubecula]

I've been using my current calibration frames for the last 12 months and was thinking perhaps I should refresh them.  For that time I have been imaging at -20C with exposures of 600sec.

Many of you seem to use much longer subs and as the mount seems to track well I was wondering if I should change to say 900s, 1200s or even 1800s.  Also whether I should move to a lower temperature.

What's really detering me from going to longer subs is the frustration of when a sub has been running for 500+ secs and a bit of cloud comes over and SGP abandons the image thus loosing nearly 10 minutes of clear sky.

I guess loosing nearly 1800s would be 3 times as frustrating.  Maybe this is a question for those living above 51 degrees lat, would you, or do you, use longer subs?

Thanks

 

 

[newbie alert]

If you can track/ guide for longer than the worm period ( usually 7 mins) then theres no reason you can't do 900 or 1200 or whatever

-20... I use -10 on my camera as it's cooling is -25 from ambient  and hopefully I'd be able to maintain the -10 in the summer months.. wouldn't have a chance with -20..my camera isn't noisy and I don't use darks for calibration

What camera are you using? 

[rubecula]

I'm using the Atik 383L.  It maybe belts and braces but I use darks and have PHD2 do a small dither every alternate frame.

I hink the mount would cope well with say 1200 but I'm worried about SGP aborting an image when clouds appear.  At least tonight I hadn't started imaging.  The forecast was for clear sky but just as plate solve had centred on the target the clouds rolled in.  It's still cloudy now despite the forecast!

[newbie alert]

7 hours ago, rubecula said:

I'm using the Atik 383L.  It maybe belts and braces but I use darks and have PHD2 do a small dither every alternate frame.

I hink the mount would cope well with say 1200 but I'm worried about SGP aborting an image when clouds appear.  At least tonight I hadn't started imaging.  The forecast was for clear sky but just as plate solve had centred on the target the clouds rolled in.  It's still cloudy now despite the forecast!

Ok, with the 383 you will need darks and that camera benefits from long exposures.. a friend showed me his single frame and then once stacked looked clean as a whistle...  I'd say 10min + subs for that camera, unless you're looking for core detail on m42!

Go for it, and no harm in trying

[rubecula]

Thanks (not so) Newbie