Canon 40D cooling mod.

[mill (Martin)]

Ok i bit the bullet today and completely modded the 40D.
I had a piece of aluminium sticking out of the camera for some time that was connected and isolated onto the cmos.
Today i fitted an peltier onto it, testing it as i type.
It has gone to -11.5C, and before i started it was 20.5C, that is a temp difference of 32C
Nice and steady on -11.5C.
Looks like i better make it regulated so i can leave it at about 0C and have the temp constant during summer.

I will not go into how to open the camera etc and how to do the mod itself

First photo is the modded 40D.
Second photo is the temp (yes that is a - infront of it
Third photo is 10min dark at 21C.
Fourth phot is same as above but at -11.5C

Dont do this at home without an good dose of booze

[DavidU (Dave)]

Thats great Mill ! You must explain the aluminium heat sink and how it is mounted to the CMOS

[mill (Martin)]

The strip is a straight piece of thin alu covered with thin isolation tape (there is not much room between the ccd and the circuit board that goes on top of it).
The strip is held in place with very thin double sided tape and made airtight all around with silastic.
At the end where it will come out of the camera i had to bend it 90 degrees down and then 90 degrees back so it can go thru a slit i made between the two connectors (usb, video etc.)
At that end i had a fin large enough to fit on an peltier element (all this has to be insulated with tape.
Then i had to shorten a usb cable end to fit between the alu and the camera (i cut all the rubber off and then bend the connector 90 Degrees.)
To make it all so i can use the camera without the cooler, i made it so it can be separated easely (see bar under camera in the picture.).
I didn't take note of all the measurements so i can't give you those

[matt]

Very nifty, Martin....and very brave

Not quite ready to do something like that with my 40D.

[leon]

Interesting Mill very Interesting, I have for ages looked at and considered different ways of cooling the 5D.

Layed in bed night after night thinking of some very strange ideas.

Leon

[mill (Martin)]

Mat and Leon it is not that hard to do, you just hve to do it.
I did some testing outside tonight and got it to -18.5C without dewing up
Here is a single picture of the Helix neb of 20 minutes.

[leon]

Not bad Mill, actually very good work.
So Mill as i see it, and to cut a long story short you are actually just cooling the alumimium strip that you have inserted behind the Sensor, with the peltier cooling device.

Dose the cold supplied by the peltier cooler slowly cool down the whole piece of alumimium

I might be miles off here but that is the way i have read it
Leon

[mill (Martin)]

Yes Leon it cools down the whole piece of aluminium, the cold that goes to the cmos goes down slowly, about 6C a minute.
Even at - 18.5C it didn't dew up.
I will do some more tests whem the weather is better and clear.
PS: i left a small part of the strip outside the camera not covered so when the peltier gets switched off the moisture can settle there and dry off.
A good test will be the Snake Valley camp

[leon]

I will be looking forward to seeing that Martin.


Leon

[Bassnut (Fred)]

Martin

A cool project, congrats for the guts to try it.

Im attempted something similar with a 300D, found aluminium a poor thermal conductor, and switched to copper. The temp at the peltier was quite different to the sensor temp with aluminium.

Im a bit confused. At less that 0 c, I got hard frost on the finger and dew on the sensor, yet you dont have dew at -11c, how do you avoid that?.

[DavidU (Dave)]

Based on 1 W/(mK) = 1 W/(moC) = 0.85984 kcal/(hr moC) = 0.5779 Btu/(ft hr oF)
The thermal conductivity of Aluminium is 250 and copper is 450.

[Bassnut (Fred)]

Originally Posted by DavidU

Based on 1 W/(mK) = 1 W/(moC) = 0.85984 kcal/(hr moC) = 0.5779 Btu/(ft hr oF)
The thermal conductivity of Aluminium is 250 and copper is 450.

Exactly

[DavidU (Dave)]

You could use pure silver =429
Gold=310
LOL

[Bassnut (Fred)]

Or diamond .......or the best......carbon nanotubes.

[ozonejunkie]

Very interesting project. How does this affect the high ISO noise? Would be great to see a RAW dark frame at the highest ISO at room temperate and cooled. Please?

[mill (Martin)]

Originally Posted by Bassnut

Martin

A cool project, congrats for the guts to try it.

Im attempted something similar with a 300D, found aluminium a poor thermal conductor, and switched to copper. The temp at the peltier was quite different to the sensor temp with aluminium.

Im a bit confused. At less that 0 c, I got hard frost on the finger and dew on the sensor, yet you dont have dew at -11c, how do you avoid that?.

When you always keep an filter on the camera, the air in front of the sensor is very moisture free.
As soon as i take the filter of, moisture can get to the cmos.
This has been a problem with every camera, as long as the air in front of the cmos or ccd is dry, it will not dew up the ccd or cmos.

At the moment i am imaging and it is on -14.6C.
Will post a raw pic without processing i about an hour or so.
The pic is just about without any noise

[mill (Martin)]

Originally Posted by ozonejunkie

Very interesting project. How does this affect the high ISO noise? Would be great to see a RAW dark frame at the highest ISO at room temperate and cooled. Please?

High iso is never a good idea, even when the chip is cooled.
Just taking pics at iso 800 and they look real smooth.

[mill (Martin)]

Ok one Lagoon image at -14C iso800 10 minutes raw converted to jpg and no processing.

http://i605.photobucket.com/albums/t.../-11lagoon.jpg

There is no noise in this image

[Jeff]

Hi Martin. Just out of curiosity ... what was the peltier brand and cost?

Jeff

[Bassnut (Fred)]

wow, thats very impressive for one 10min exposure and no darks, but the levels are all over the place, a slight tweak does it justice.

Excellent work Martin, and low noise indeed.