Peltier cooling of an astrophotography Canon 1000D

[Xen0n]

Hi all,

I know this modification has already been attempted by some of you but I thought it could be a useful ressource. I detailed this build on my website (no advertisement intended here, its my personal blog with no advertisement on it).

http://web-sys.be/peltier-cooling-of-an-astrophotography-canon-1000d/

For many years, I’ve been using my trustworthy Canon 1000D for astrophotography along with APT. While providing me with great shots of deep sky objects, this model has a drawback: ampglow. This phenomenon is due to the fact that the internal components of the camera heat up during long exposures, resulting in a “glow” in images. The solution here is to cool the sensor. I’ve seen many people using a passive cooling by attaching a fan to the back of the sensor. I decided to go a step further by using a Peltier cooling. I was already familiar with the camera internals as I took it appart to remove the IR cut filter.

Right from the start, I took into account the challenges and the risks of such modification. First, the heat generated by the hot side of the Peltier has to be dissipated. Adding a heatsink implied to cut the camera body and remove some components such as the screen and buttons. I made some tests to ensure that the camera could still work without them (as the camera is entirely controlled by APT). The second major risk resides in the condensation forming around the cold side of the Peltier. Such water droplets could easily short components on the camera PCB.

First, I removed the PCB that are close to the sensor and applied a KF 1282 tropicalisation spray. This spray should protect the boards from any water damage.

Next step was to cut away the plastic body for the quite massive heatsink.

Then, I added the Peltier and a rubber layer to avoid any contact between the metal heatsink and the PCB. I made usage of a thermal compound on both sides of the Peltier.

In the meantime, I wondered if I could move the screen and buttons to a remote housing.

Thus functional, this was bulky and useless as APT allows me to control the whole camera remotely using USB connection. But still good to know…

I noticed that the running fan of the heatsink generates quite a lot of vibrations which could result in blurry images. To solve this issue, I added vibration dampeners. I used hot glue which allows for future removal while providing a decent amount of fixture. My concerns are regarding the long term adhesion and its resistance to sub-zero conditions. We’ll see…

Results of this low budget system are very good, no more vibrations on the camera body.

The heatsink is attached to the camera body using 3D printed parts on the bottom and a metal sheet at to top. I also added a switch allowing me to turn the Peltier OFF while keeping the fan running. The reason for this is to dissipate residual heat once the imaging session is done and before putting the telescope away.

[Update] Well, hot glue has its limits. Temperature variations lead to a bounding failure. I therefore designed and printed a decent support for the fan.

Those vibration damping balls have a nice profile allowing an easy fixation.

And here is the final result.

Overall design is better and hopefully more sturdy.

 

 

[Andy56]

Brilliant. I don't know if I would have the courage to mod my 600d yet. May be I could buy a faulty camera first.

Do you have any before and after shot. I guess it may be too early to have any.

I'm going to try the polyurethane box with Peltier first. I'll build this before the summer come around.

Cheers

Andy