Hi,
I have recently completed constructing the "Martin Pyott" external peltier cooler for my Canon 650D
I am most pleased with the simplicity of the project and the fact that the camera is left intact.
I was able to keep my sensor to a stable 13 degrees C the other night when photographing Carina. Outside temp was 18.5.
To prevent any condensation from finding its way into the adjacent buttons i used a piece of plastic from a glad bag between the peltier cooler and the back of the camera which extended past the sides of the cooler by about 20mm all way round forming a shield for any water to run off but not into the camera.
John