Reusing Dark Frames

[Icearcher]

Hi All

A question on dark frames:

At present, I collect my dark frames at the end of each night out, I usually managed to get 12 darks (an hours worth of 5min subs) and usually find that I can use about 10 as the first two are often out due to temp.

My question, since I capture 5 min subs at iso 800 almost every time and I now have quite a few that are all around the same temp, can I reuse darks from other nights out as long as I can get the temp to match?

Is there anything I need to know in regards to building a darks library.

The aim is less time collecting darks and more time collecting photons. :)

[RobF]

Hi Chris

If you have a thermometer on your imaging rig (even just a cheap one attached with velcro) then no reason you can't assemble a darks library - for Canon DSLRs you're probably ok if within 2-3 degrees, or even 5 deg.

Remember you can shoot them on cloudy nights, or inside in a closest (or even the fridge).

My wife was puzzled one night why the air con was going full bore when everyone was asleep upstairs. Said I needed more darks at 19 degrees and seemed a fair enough way to get them :lol:

[gregbradley]

You can use adapted darks that are not temp dependent as they work off the bias.

Images Plus does that. So does CCDstack.

Greg.