Hi guys,
I just finished what I consider my most ambitious project to date.
My little DSI-II Pro can now be cooled down to around -10C without condensation! It is a copy of a project submitted by John Love in the Meade-DSI yahoo group. The idea is to have the CCD PCB inside an insulated chamber, with the peltier module isolated from the chamber and with desiccant packs inside to get rid of the remaining humidity inside the chamber.

I am positive I cannot achieve a perfectly sealed chamber, so I decided to include a humidity sensor. This way I can measure the rel. humidity inside the chamber before I start an imaging session, to check how much I can push down the temperature. Here are some pictures of the final product.



The lecture of 0.82V stands for around 1.15% relative humidity at 25C (According to the sensor's datasheet). This allows to cool down the camera to around -12C without any condensation.

And here is the humidity sensor:


Best regards,
Pablo

Hey Pablo -

That's pretty... COOL! How much weight does that add to the outer end of your setup?

Thanks Dave.

I think it will add about 1.5 to 2 lbs. most of it coming from the massive heat sink. It shouldn't be a problem since there is already an extra ring on my mounting setup to support the focuser tube.

OK.........Now show us some results............

Awesome! (and ditto on showing us some results)
Mike

First light, and it came from the Pelican in Ha.
The camera was cooled to 0C, 12 subs 10min each. Full moon and not very clear. Humidity above 90% and no dew

Awesome picture - particularly for the light conditions!!
Mike

Thanks Mike,
I was able to capture some frames with the OIII filter yesterday. Here is a try of false color using Ha for luminance and red, and OIII for green and blue channels. I had to stretch the histogram way more than I'd like to, but the weather hasn't been cooperative, oh well,...,

Pablo,
I'm always amazed at the high quality of your astro photos! The Ha always adds alot of detail. Looking forward to your instructions at MMSP!
Mike

Pablo, this is a GREAT image! Congratulations on winning the open imaging contest on the Meade DSI imagers YahooGroup, too!! This picture deserves it.