It is nice and clear here in Melbourne but is has been hot. It is still 25 C outside. I set up tonight and decided to get the Peltier fridge to do a bit of work. It is holding the camera environment at 15 deg C below ambient. Looking good so far.
In the first picture from left to right lens temp, ambient temp and camera or fridge temp.
Even 15C drop in camera temperature makes a lot of difference to the level of noise.
My tinnies are at 3C!
I also lashed out and bought DSLR remote which allows me to better fully control the 5DH from the laptop. It is obvious I don't have access to the camera controls when it is in the fridge.
That looks pretty cool Bert what a great idea, i have been thinking of ways to keep the camera cooler as well, coming up with all sorts of weird and wonderful things, but nothing yet.
Even considered some sort of jacket for the 5D with coolent running through it,
Leon
By the way Bert, although i do have some temp gauges for the lens and Tak, the ones you have look pretty good where might you have got them from.
Leon it gets better as ambient drops. It s now 21.5C and the fridge is at 5.0C. The fridge is held firmly to a redgum 'plate' that holds both lenses. There is no vibration transfered to the Canon lens and camera by the two cooling fans one inside the fridge and one speed controlled on the peltier junction heatsink. The temperature sensors are thermistors, the sort that are used for monitoring computer component temps. They are reasonably cheap and run on 5V.
It is all a matter of controlling harmonics.
Snowyskiesau it takes quite a while, one hour plus. It is not just physically carrying everything out but getting everything connected correctly. It is very difficult to troubleshoot in the dark.
My system has grown organically as each bit is added. The desktop (DOS) in the background controls the mount. One laptop does the guiding control and the other runs the stepper focuser and the camera. Both laptops are wirelessly linked to my network inside. If needs be I can remotely control them.
Gee very nice Bert. Do you ever get problems with condensation?
Scott
EDIT: I just read your reply to a similar question on the other thread, yes it makes sense, essentially your fridge is like a Frost Free fridge, any condensation or ice will always gather on the coldest part, the peltier, thus leaving the slightly warmer rest of the fridge dry and below 100% RH.
Bert, this is something I'm wanting to do as well with my planetary setup - as you say, dropping the temp decreases the noise a lot. I think I read somewhere that the noise drops by 3db for every 7C drop in temp.
For me this is effectively giving me a larger mirror (but no resolution increase) due to the increased s/n. Probably a lot cheaper to build something like this than buy a mirror 2x the size of my current 13" :-)
np Lester, I'd have to use a totally passive cooling setup, or else switch off the fans when I image. If the enclosure was well insulated I could probably go 10 minutes without the cooling running.
what a great idea, i have been thinking of ways to keep the camera cooler as well, coming up with all sorts of weird and wonderful things, but nothing yet.
