CCD Temperatures

[cardconvict]

Question for people with CCD's but what default cooling temperature do you keep your camera at all year round.

I have been thinking about -15c or -10c or lower if the ambient temperature stays cool enough but being thinking off creating a darks libary for the whole year.

[libraryman]

I always set to -20C

Ray

[steppenwolf]

Because I can, I choose -20c all year round but many cameras cannot do this in the summer so a compromise might need to be accepted. If I am honest, I don't see any difference in -20c v -10c in my image noise although I have not analysed this exhaustively! I would aim for a minimum of -10c as it is highly likely that most single stage cooled CCDs will achieve this on most occasions but if you do have a two stage cooler then aim for a lower temperature.

[Starlight 1]

Good point Steve about summer . so -15  but I good for -20 later .

[cardconvict]

I have a starlight xpress trius sx694 and says it will cool to a minimum of -40c below ambient temperature it has a cooler and a cooler fan on the outside.

[ollypenrice]

With the Sony chip in the 694 you'll find precious little difference between -15C, which it should manage all year round, and -20C which, in a lovely hot summer, it might not! I no longer use darks, so matching darks to lights in temperature doesn't matter, even with my noisy full format Kodak chips. I suspect your best results would come from cooling as hard as you can and using a master bias as a dark and dithering between subs. You could use a bad pixel map as well but on a Sony chip, dithered, will it matter?

(We just did a test with a guest's QSI583 (Kodak 8300 chip, dither guided) and tried substituting master dark and master bias on separate stacks. There was no difference.

Olly

[cardconvict]

24 minutes ago, ollypenrice said:

With the Sony chip in the 694 you'll find precious little difference between -15C, which it should manage all year round, and -20C which, in a lovely hot summer, it might not! I no longer use darks, so matching darks to lights in temperature doesn't matter, even with my noisy full format Kodak chips. I suspect your best results would come from cooling as hard as you can and using a master bias as a dark and dithering between subs. You could use a bad pixel map as well but on a Sony chip, dithered, will it matter?

(We just did a test with a guest's QSI583 (Kodak 8300 chip, dither guided) and tried substituting master dark and master bias on separate stacks. There was no difference.

Olly

Thanks for the input Olly. I did some darks last night and was amazed how clear they came out such a difference from DSLR

[Starlight 1]

Ido have the 694 and test in my fish room doing darks , room set at 25c all year round camera can hold -28  that it .

[cardconvict]

6 minutes ago, Starlight 1 said:

Ido have the 694 and test in my fish room doing darks , room set at 25c all year round camera can hold -28  that it .

If that's the case I should easily reach -20c all year round if i wanted

[ollypenrice]

1 hour ago, cardconvict said:

If that's the case I should easily reach -20c all year round if i wanted

You need to move to a better climate!! I mean, wearing long sleeves on all nighters in August, nooooo.....

lly

[cardconvict]

God I wish I could do that but in lincolnshire it is very rare it gets hot. Maybe in the olden days it did LOL.