Imaging at various temps

[Saturn488]

I took a few shots the other night with my camera being at -14 - -20degrees but tonight since it’s warmer I can only get it down to around -9.

How does one combine photos of the same target when taken at different temps?

[RyanJones]

Hi Chrys,

You can still combine the images, you just need a set of darks to suit each sensor temperature. Ideally open another tab in DSS ( if that's what you use ) so that you can associate each set of darks with its appropriate lights.

Regarding temp though. Most cameras with PEC coolers will only cool a given amount below ambient hence why on a hot night you couldn't cool as low. Generally there are diminishing gains by going any cooler than a certain point for a given sensor anyway. By not going to the coolest possible you give yourself some headroom for warmer nights and won't run into this issue.

Cheers


Ryan

[gregbradley]

You can also scale your darks and you need a bias for that. Its an option in CCDstack.

Best practice is to use a temperature on your camera you can achieve all year round except perhaps for the very hottest nights.

CMOS cameras these days are pretty clean so no real gain going -20. 0 to -10 is a common temperature setting. Sounds like you need to use around 0C so its achievable.

Greg.

[multiweb (Marc)]

Originally Posted by Saturn488

I took a few shots the other night with my camera being at -14 - -20degrees but tonight since it’s warmer I can only get it down to around -9.

How does one combine photos of the same target when taken at different temps?

Temperature will only affect your calibration. It has no bearing on your subs. You can mix them. I've had stacks made of subs taken years apart.