ATIK460EX - loving it - Dark Frames and Camera Temp

[Fordos Moon]

Hi All,

As i work on processing only my second ever CCD image following a couple of years of DSLR imaging, I ponder a couple of questions as I read up on CCD imaging.

1. There appear to be some who talk about taking Dark Frames, and others that say they are not needed. Your thoughts?

2. I have been cooling my camera to minus 10 degrees. Can anyone confirm this is about right for my camera?

Thanks as always,

Super-Excited Bob

[red dwalf]

With the sony chip cameras which is what you have, I find taking darks are not needed, I find it more beneficial to take flats.

the camera will cool to 25 below ambient temp, so if its 5 degrees outside your camera will cool to minus 20, I tend not to max my 314 cooler out so go for about minus 15.

its a great camera.

[Sp@ce_d]

I stopped using darks with the 314L+'s some time ago. I was finding they introduced more noise than without. I used to cool to -20 but use -10 now as I can hit that constantly throughout the year. I know you have a 460 but the Sony sensors are pretty quiet so would expect the same if not better. As with everything, experimentation will give you a better idea. I haven't even bothered with any calibration recently & noticed more of a difference than I expected concentrating on getting better quality subs, being picky when sorting them etc. produces better results without calibration than trying to make a silk purse etc etc.. Using calibration & all the tools in the workshop! [emoji3]

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[johnrt]

No need for darks on a 460ex, -10 is fine, I go for -20 and there's only a few really warm nights a year I can't get down to -20.

[Fordos Moon]

Thanks so much guys - music to my ears!

[lensman57]

Hi All,

As i work on processing only my second ever CCD image following a couple of years of DSLR imaging, I ponder a couple of questions as I read up on CCD imaging.

1. There appear to be some who talk about taking Dark Frames, and others that say they are not needed. Your thoughts?

2. I have been cooling my camera to minus 10 degrees. Can anyone confirm this is about right for my camera?

Thanks as always,

Super-Excited Bob

You do not need Darks with a Sony sensor which is cooled to -10C. There is very little gain in cooling the camera below -12C ~ -13C. The reduction in dark current is still measurable but not significant. Kodak sensors do need to be @ - 20C and below. My advice is to enjoy the camera and the imaging and not get bugged down with technicalities. To get rid of the hot pixels a Sigma Clipping stacking routine plus a bad pixel map/ cosmetic correction  will remove almost all of the offending pixels.

A.G

[ollypenrice]

You could always try making a master bias and using that as a dark, or simply try not bothering at all.

Many stacking programmes (I use AstrArt5) have a hot pixel filter option and this will almost certainly for for any that you happen to have.

Olly

[ianaiken]

I'm with everyone else I don't bother with darks in the 460exm just get a good bias and flats. I do cool it down as far as possible for after reading this thread ill not bother and just stick to around -15C

[NickK]

Just to add - the reason why you need the cooler power is that on the warmer summer nights and in warmer locations you need that power to get to -15 or -20. Nice thing is that the 400 series seems to have more cooling power than the 383L..