Astro Camera's - to cool or not to cool

[Outcast (Carlton)]

Originally Posted by JimsShed

I made a cooler for my ZWO ASI185MC. Similar body to your 224's. Here in Brisbane over the summer the best delta I could achieve was about 15 degrees. So for me that translated from avg 34c sensor temp down to 15c. And after all that, my images were no better.
My camera was mounted in the eyepiece diagonal and everywhere that wasn't covered with the neoprene insulation was very cold to touch just like a cold can of beer. The problem with the DIY approach is the coldness doesn't get directly to the back of the sensor, and unfortunately I couldn't put a heat sink directly on the back of the sensor because there is a circuit board there. If you had a mill to machine some sort of enveloping heat sink around the perimeter of the sensor you might get a better result.
The other problem you will run into is the lack of cooling temp consistency from one night to the next, and even throughout the night; you would need to write some software to monitor the temp and regulate the cooler so you weren't constantly having to make new sets of darks for each temperature level. Sigh.

Originally Posted by JimsShed

Forgot to mention. I also got full-on condensation on the filter I had put in front of the camera to protect the sensor.

Thanks Jim,

Very useful to know.. as you probably know, our heat & humidity is even worse up here in Cairns.. that's why I was considering just heat sink & fan, to try & avoid that moisture problem...

It's gone off my list of priority projects at present but, next time I'm in Jaycar I might see what the bits will cost.. having said that though, if you got little improvement with a 15* drop in sensor temp.. I suspect chasing 5* will probably just be a waste of time.

Cheers

Carlton

[raymo]

Noise really starts to drop off below about 12-15, and freefalls once it gets
down into single figures. At about 4-6 noise was negligible with my 1100D.
raymo

[Outcast (Carlton)]

Cheers Raymo,

I suspect I will never get down to those temps up here.. best ambient low temp we get up here is about 14*, maybe a few nights of the year in the dry season.. if we are lucky...

I think the only way I will beat this in the end is with a dedicated, cooled Astro camera & to be honest, I don't think I can justify that expense.

I'll do my best to turn off any unnecessary in camera stuff, that will help to some degree but, probably not that much..

Originally Posted by raymo

Noise really starts to drop off below about 12-15, and freefalls once it gets
down into single figures. At about 4-6 noise was negligible with my 1100D.
raymo

[Camelopardalis (Dunk)]

Carlton, you will get more thermal related noise with warmer ambient temperature, but the nature of it is somewhat random, so once you get going with your mount and all the software to control it, just enable dithering and it will help a lot with that. And then there’s always the old adage, just take more subs

Contrary to popular belief, you don’t always have to spend more money to enjoy the hobby and get good results

[raymo]

The battery generates heat when powered up. Get a dummy battery for your 1100D on ebay, cheap as chips. It all helps. Once you begin stacking in earnest, stack large numbers of subs, that helps too. Sorry, Dunk just said that.
raymo

[xelasnave]

I have been thru the diy cooler but would say live without it and see how you can manage without via dithering and proceesing...and realise that one day you will probably want a dedicated cooled colour camera or horrors a narrow band set up...I was of the keep it simple approach until I decidedvto go narrow band...the difference was incredible and all I can say is if you keep at it you probably will end up narrow band...so be careful of wasting money in small fixes and just put money aside for narrow band one day...I wish I had not bought my nikon or 8 inch and just bit the bulet and got my 80mm and zwo narrow band set up first up...I would have saved $1k on the scope and $700 on the nikon...and each although handy are not as useful as the narrow band 80mm...I will set the 8 unch up but there is so much to do to make it really decent...the tube needs more structure as its like a tin can..more money and really needs a better focuser and its big...the 80 is less but the focuser is ok and its just so easy to manage compared to the 8 inch.
I cant see the 8 and the nikon being used as much as the 80mm.

I like you thought..oh its just too much money..but its not...tell me..how much do you need to spend to get a good bass and good amp?...mmm why not just get a cheap one☺
Alex

[sil (Steve)]

For the desparate you can usuaaly easily unpin the battery cover on your dslr as most have some sort of spring clip holding the battery in the body anyway. This can allow the night air to help cool the battery as it heats up during use. Probably wont do squat for your imaging but should at least help battery life


Also before you experimenters waste a ton of money at jaycar on peltiers to play with, be advised they are expensive markups there. Instead jump on ebay and for under a fiver you can find chep crappy "usb drink coolers" that wont do squat for your drinks either but its a peltier, already wired to a usb connector and switch and often with heatsink and fan too all in some ugly chunk of plastic. Its a perfect buy to start experimenting with a peltier. Its what I installed on my zwo120mc and gives as good 13 deg delta. Cut out the lower power peltier and solder in a higher power one for more cooling..

Wonder if anyone's tried doubling peltiers, use a high delta one to suck heat out and sandwich a reversed lower delta on top to take the cold and realease heat on the outside straight to the air.. no interference from fans to worry about or bulky heatsinks? then build your pier with heat pipes to send heat into the ground? and pipe heat from all devices then into pier?

then there's the martian heat ray of course.

[Outcast (Carlton)]

Thankyou Gentlemen,

All good advice; I will investigate the dummy battery idea a little further.. a quick look on Ebay revealed they are indeed cheap as. The additional advice is appreciated from alcon.

Cheers

Originally Posted by Camelopardalis

Carlton, you will get more thermal related noise with warmer ambient temperature, but the nature of it is somewhat random, so once you get going with your mount and all the software to control it, just enable dithering and it will help a lot with that. And then there’s always the old adage, just take more subs

Contrary to popular belief, you don’t always have to spend more money to enjoy the hobby and get good results

Originally Posted by raymo

The battery generates heat when powered up. Get a dummy battery for your 1100D on ebay, cheap as chips. It all helps. Once you begin stacking in earnest, stack large numbers of subs, that helps too. Sorry, Dunk just said that.
raymo

Originally Posted by xelasnave

I have been thru the diy cooler but would say live without it and see how you can manage without via dithering and proceesing...and realise that one day you will probably want a dedicated cooled colour camera or horrors a narrow band set up...I was of the keep it simple approach until I decidedvto go narrow band...the difference was incredible and all I can say is if you keep at it you probably will end up narrow band...so be careful of wasting money in small fixes and just put money aside for narrow band one day...I wish I had not bought my nikon or 8 inch and just bit the bulet and got my 80mm and zwo narrow band set up first up...I would have saved $1k on the scope and $700 on the nikon...and each although handy are not as useful as the narrow band 80mm...I will set the 8 unch up but there is so much to do to make it really decent...the tube needs more structure as its like a tin can..more money and really needs a better focuser and its big...the 80 is less but the focuser is ok and its just so easy to manage compared to the 8 inch.
I cant see the 8 and the nikon being used as much as the 80mm.

I like you thought..oh its just too much money..but its not...tell me..how much do you need to spend to get a good bass and good amp?...mmm why not just get a cheap one☺
Alex

Originally Posted by sil

For the desparate you can usuaaly easily unpin the battery cover on your dslr as most have some sort of spring clip holding the battery in the body anyway. This can allow the night air to help cool the battery as it heats up during use. Probably wont do squat for your imaging but should at least help battery life


Also before you experimenters waste a ton of money at jaycar on peltiers to play with, be advised they are expensive markups there. Instead jump on ebay and for under a fiver you can find chep crappy "usb drink coolers" that wont do squat for your drinks either but its a peltier, already wired to a usb connector and switch and often with heatsink and fan too all in some ugly chunk of plastic. Its a perfect buy to start experimenting with a peltier. Its what I installed on my zwo120mc and gives as good 13 deg delta. Cut out the lower power peltier and solder in a higher power one for more cooling..

Wonder if anyone's tried doubling peltiers, use a high delta one to suck heat out and sandwich a reversed lower delta on top to take the cold and realease heat on the outside straight to the air.. no interference from fans to worry about or bulky heatsinks? then build your pier with heat pipes to send heat into the ground? and pipe heat from all devices then into pier?

then there's the martian heat ray of course.