Old 31-03-2010, 08:03 AM
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alan meehan (Alan)
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new toy cooled 40d

Well i have finally got my my new toy back from central ds where i had a cooling unit added and modded,i have given it a test and have dropped from 26deg down to 0.1deg so iam happy with the cooling .the whole unit is fairly heavy weighs in at 1.2 kg but my jmi focuser handles it with no problems ,now all i need is some good weather to try it out.
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Old 31-03-2010, 08:25 AM
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[1ponders] (Paul)
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You've been hanging around h0ughy too long Al

Nice buy mate. Look forward to first light and then the real test. Astrofest light
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Old 31-03-2010, 04:27 PM
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Hi Alan, good purchase. I got them to modify a 40D for me a few years back and it cools to 17 degrees below ambient. I was interested to read the temperature drop you recorded, perhaps they are using a better peltier than before.

All the best with it.
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Old 31-03-2010, 05:24 PM
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I still have my 40D and it works a treat. I am planning on using it with a 200mm for those lovely wide fields that many people seem to produce.
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Old 31-03-2010, 06:48 PM
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Alan when my Peltier fridge is at -10.0C the sensor is at 7.0C. I have measured the temperature rise of the sensor in my Canon 5DH when continuously exposing. This temperature rise above ambient is 17C! I would imagine that a 40D would rise a bit less than this.

Your 40D with the sensor directly cooled will have far less noise even at a sensor temperature of 7.0C. I would imagine the trick would be to drop the sensor temperature to a level where condensation just occurs. Then warm up to clear the sensor and stay above this sensor temperature for these ambient conditions.

The dew point would be the important parameter here. What would help is some mild heating from a dew strap around the lens or telescope barrel to raise the dew point inside the lens or telescope barrel. A filter or clear window with anti reflection coating mounted as close to the sensor as you can manage would stop fresh moist air forming condensation on the sensor.

If I don't continuously expose with dummy exposures when the fridge gets below about 0C to -5C I get condensaton.

Hope my ramblings give you some ideas. Looking forward to what you can achieve with your new cooled 40D. It is well worth it as the dim stuff is at or below the noise levels of uncooled cameras.

I can only imagine what a Canon sensor would do at -40C!

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Old 31-03-2010, 09:23 PM
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strongmanmike (Michael)
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Looks awesome AL!

Hope it proves just the trick

..?..just something about big black cameras

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Old 01-04-2010, 09:18 AM
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dugnsuz (Doug)
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I look forward to hearing how you go with this Alan as this mod has been on my wish list for a long while now.
Wow - it dropped 26 degrees on the bench eh!!??
Very promising.
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Old 01-04-2010, 11:39 AM
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Alan congrats on the new cooled camera mate, looking forward to seeing the results.

Originally Posted by [1ponders] View Post
You've been hanging around h0ughy too long Al
Mr Ponderosa, leave Hoss alone.....
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Old 01-04-2010, 12:37 PM
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Congratulations Al. I'm keen to see some images!!
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Old 02-04-2010, 07:58 AM
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Nice! Sounds similar to cooling capacity and weight to my home modded 40D but nice and professional!
I find sitting at 5 degrees gives me practically no noise..
You`l have fun with this!
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Old 04-04-2010, 06:43 PM
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Hope you get all this sorted and obtain some great images
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