[rcheshire (Rowland)]

I've been investigating methods of cooling a DIY refurbished, Astrodon Inside modded 5DMKII (aside from a centralds mod), which led here and there, with mixed results.

This camera makes a brilliant wide field instrument. I love it.

I read somewhere that Spencers use a passive method of cooling the sensor. Basically, bleeding heat to the camera frame - which gave me an idea. Good or bad, is yet to be determined.

As you can see from the images below, I have made a cold plate/finger to fit to the back of the sensor - it will be insulated from the electronics with a moisture barrier.

This particular mod will use a very low power linear driven TEC device installed under the tongue of the cold plate, consuming no more power than my dew heater.

Heat from the other side of the TEC will be conducted to an external active heat sink by a copper strip. The copper strip will be insulated from the camera chassis, held in place by heavy duty double sided tape.

It won't get that hot. Not like the one used on a previous temperature regulated 1000D cold finger, which had a massive heat sink. All it needs to do is take the edge off the dark current without frosting the thing to bits.

The mod could dispense with the TEC by extending the cold plate tongue and fixing it to the camera chassis or extending it outside to an active heat sink, which I think would work very well.

I'm waiting on a 30mm x 15mm x 3.6mm TEC module that will tuck in nicely.

I will add images over time.