Gary Honis
Vendor-DSLR Mods
Reged: 12/15/04
Posts: 220
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Using a Coleman 12V beverage cooler and a small metal Community Coffee canister, I made a peltier cooling system for my Canon 450D (XSi). Some photos posted here:
http://ghonis2.ho8.com/rebelmod450d16.html
Cooling the whole camera is easy with the 450D because of its small size and weight. Since it has one USB cable for all computer control and imaging functions, there is no need to press buttons on the DSLR or view its display. I'll be posting complete construction details along with test results from the cooled camera soon.
Gary Honis
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Gary Honis
DSLR Modification Service
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Andrew Welsh
Carpal Tunnel
Reged: 03/28/06
Posts: 2488
Loc: Rochester, NY
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Let me be the first to say... cool, man. 
Har har.
Thanks for the writeup, I may do this project some day.
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LX200 8" classic, f/10, Meade eq. wedge, .63x FF/FR
Canon 40D and 5DMkII, unmodified
Canon EF 200/2L IS, 300/4L non-IS, 100/2.8 Macro, 50/1.4, 85/1.8, 35L, 24L, 16-35L and Peleng 8mm fisheye
Orion Apex 102mm (4") Mak-Cass
Pimped out with accessories and bling
My DSLR Astrophotography Webpage and photo bucket with full equipment list
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Gary Honis
Vendor-DSLR Mods
Reged: 12/15/04
Posts: 220
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Andy,
Another cool feature is that beer cans still fit in the cooler for those cloudy nights 
Gary
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Gary Honis
DSLR Modification Service
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JerryWise
Postmaster
Reged: 12/26/03
Posts: 7834
Loc: Lexington, SC
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Great job. I'll sure be waiting for your writeup.
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Jerry
Celestron C-11
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waassaabee
Carpal Tunnel
Reged: 11/26/07
Posts: 2700
Loc: Central California Coast
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Gary... That's sick !! I think I have everything to make one too! Well except the Coleman cooler, and the 450D... 
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Gary
34N 120W
-My kingdom for blue squares!-
WO Megrez 90FD/TV 0.8x FR/FF
AT8RC
mini Borg 50/Q-Guide/PHD
CGEM
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My Friend Flickr
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Nils_Lars
Post Laureate
Reged: 01/04/08
Posts: 3422
Loc: Santa Cruz Mountains , CA
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Thats a cool project , would be nice for those summer nights.
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Erik
Orion Atlas Self Hypertuned (EQMOD)
Orion ED 80
Williams Optics VII reducer
Celestron 8" SCT
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http://www.flickr.com/photos/31986095@N05/
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walt r
Post Laureate
Reged: 02/13/07
Posts: 3463
Loc: Doylestown, PA
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Looks good, just the thing for those still hot nights. I would like to see a graph of the dark noise vs. the temperature of your system.
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Walt
Obsession 18" f/4.45 #1370 AN/SC
MK67 Deluxe 6" f/12 Mak-Cass, Super Polaris GEM, JMI MicroMax DSC
DIY 60mm f/6 Achromat
Cookbook 245 CCD
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wrather1
AstroBear
Reged: 10/25/05
Posts: 3880
Loc: Dallas, Texas
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Very cool! 
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"Don't worry about what telescope you own, or its quality. Just get out under the night sky, and enjoy God's wondrous universe." - T. M. Back
Meade RCX400-12 "Ursa Major"
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Ptarmigan
Carpal Tunnel
Reged: 09/23/04
Posts: 2356
Loc: Arctic
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Cool idea.  I like to see the results.
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Ptarmigans=Cute and Cuddly
Meade Starfinder 8
Nikon 10x50
Rebel XT
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Lee Jay
sage
Reged: 02/27/08
Posts: 463
Loc: Westminster, CO
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I've never understood something about cooled sensors/cameras. How come they don't just fog up like crazy and therefore fail to produce images?
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LLEEGE
Running out of Oxygen
Reged: 03/03/05
Posts: 9071
Loc: Cloud-chester,NY
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I would imagine that as long as the sensor is not cooled below the dew point, it shouldn't fog. Cooled CCD's are sealed in an inert gas chamber to prevent fogging. (no moisture to condense.
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"Okay! You draw the straws. I'm-a taking the parachute."
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Mike B.
Carpal Tunnel
Reged: 10/24/05
Posts: 1687
Loc: Louisiana
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Quote:
I've never understood something about cooled sensors/cameras. How come they don't just fog up like crazy and therefore fail to produce images?
I would think the humidity level would dictate whether it fogs up or not. You could put a bag of dessicant inside if it was too high, maybe?
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Clear skies!
Mike B.
My Homepage and Astrophotos
Edited by Mike B. (07/08/08 10:22 PM)
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Gary Honis
Vendor-DSLR Mods
Reged: 12/15/04
Posts: 220
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Thanks for the suggestion, will do. I also thought an animation of the dark frame crops as they improve over time and lower temperature would be good.
I had a chance to test the peltier cooled 450D on my scope tonight. I took 5 minute dark frames every 5 minutes with a 55 second pause between exposures over a three hour period. The results were discouraging. After 30 minutes I only got a 7 degree Fahrenheit drop and after one hour the system leveled out at a 10 degree drop. In comparison, tests with the camera in the orignial cooler gave a 17 degree F drop in 30 minutes and a 23 degree drop at one hour continuing to a leveling out at a 30 degree drop below ambient.
Guess it's back to the drawing board:(
I thought maybe there was conductance from the camera body through the T-ring into the telescope focuser, but I later tested the cooler removed from the telescope and there was no change in cooling.
I'm thinking maybe there is not good conductance between the peltier and the coffee canister? I fine sanded the coffee canister metal and used thermal paste but maybe I used too thick of a layer of thermal paste? Or maybe the conductance of the metal used in the coffee canister is not that good and I need to add some aluminum strips or a heat sink inside the canister? Maybe the R value of the styrofoam cooler I used is too low? Maybe its a combination of the above.
If anyone has advice, please let me know.
Gary
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Gary Honis
DSLR Modification Service
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SuperDuperMan
member
Reged: 04/21/08
Posts: 67
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Hi Gary!
You "fridge" looks very nice. My simple cooling system has not been tested under the stars yet, but initial indoor dark frame results were ok, I think. I did not measure any temperature, only the noise in the dark frame. See this message:
http://www.cloudynights.com/ubbthreads/showflat.php?Cat=&Board=DSLR&Number=2427231&Forum=f85
Best of luck,
Søren
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Kentari
scholastic sledgehammer
Reged: 11/19/06
Posts: 794
Loc: Belgium
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Very nice! I look forward to your writeup. I've been considering building something similar too, but it is't as straightforward with a 20D (no live view etc...). My new 40D will arrive one of these days reducing the number of cables needed to 1... Now I only need a more decent laptop to control it.
Koen
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Darkstar 355 f/5 Dobsonian
Orion UK 8" f/4.5 Newtonian and WO ZS 80 FD on Losmandy GM8
Canon 20D DIY mod with Baader filter
A bunch of lenses: 10-22mm f/3.5-4.5, 17-40mm f/4, 50mm f/1.4, 70-200mm f/2.8, 300mm f/2.8
www.koenvangorp.be
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Gary Honis
Vendor-DSLR Mods
Reged: 12/15/04
Posts: 220
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Søren,
Thanks for the link. Didn't see a photo of your cooler, do you have one? Bert really has created a cooling monster there!
Gary 
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Gary Honis
DSLR Modification Service
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SuperDuperMan
member
Reged: 04/21/08
Posts: 67
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I did not post a picture because it is very similar to this one:
http://www.pbase.com/terrylovejoy/peltier_cooling
I.e. just a plate attached to the camera hole in the camera and the peltier is attached to the plate.
Søren
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Gary Honis
Vendor-DSLR Mods
Reged: 12/15/04
Posts: 220
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Søren,
Very simple system!
I'm getting closer to a solution to my problem. Using two temperature probes, one directly on the cold plate support inside the cannister, and another nearby inside on the canister wall, I found that the cold plate probe gave a temperature drop in ten minutes of 40 degrees F below ambient while the coffee canister dropped only 10 degrees. So now I'm checking if I have a good cold plate to canister connection or if I need to add some aluminum to aid in cooling inside the canister. It's good to know I'm getting that big temperature drop inside the canister. Now I just have to get that cold into the camera. Recorded a 50 degree temperature drop at one point and it warmed my heart.
Gary
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Gary Honis
DSLR Modification Service
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walt r
Post Laureate
Reged: 02/13/07
Posts: 3463
Loc: Doylestown, PA
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I'm thinking that you need to thermally connect the cold plate directly to the camera.
What comes to mind is a silicon pad to contact the rear of the camera body. Silicon pads are used to heat sink electronic devices when thermal grease would cause a problem.
A manufacturer is Berquist. Check DigiKey part number BER165.
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Walt
Obsession 18" f/4.45 #1370 AN/SC
MK67 Deluxe 6" f/12 Mak-Cass, Super Polaris GEM, JMI MicroMax DSC
DIY 60mm f/6 Achromat
Cookbook 245 CCD
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Gary Honis
Vendor-DSLR Mods
Reged: 12/15/04
Posts: 220
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Hi Walt,
The 450D has a plastic body. The rear (back side) of the 450D body is mostly the large display screen. The tripod mount on the bottom does make connection with some metal strips inside the body of the camera. The right side of the 450D is mostly the battery compartment and it is plastic. I know it would be best to directly cool the imaging chip with a peltier, but I thought I would try whole camera cooling, just as if you were imaging on a night with a 40 degree Farenheit ambient temperature. These peltier coolers keep food cold so why not a camera? Over time in the cooler, the camera should adjust to the temperature of the peltier cooled chamber. Resulting dark frames will be the measure of how useful the cooling system is.
Gary
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Gary Honis
DSLR Modification Service
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