thermoelectric cooling box

Discussion in 'Astrophotography' started by georgian82, Mar 22, 2016.

  1. georgian82

    georgian82 Mu-43 Regular

    Jan 17, 2014
    Hi guys,

    So in my attempts to keep pushing the boundaries of my modified EPM2 and lower the amount of noise during long exposure astrophotography, I have decided to build a thermoelectric cooling box and I wanted to share my experiences with it in case this could be of benefit for anybody else too.

    It is basically a box built out of aluminum sheet that is wrapped with an insulating material. A thermoelectric peltier cooler is then attached to this box with the ceramic plate touching the outside of the box transferring cold into the inside of the box. There are two heat sinks, one on the outside dissipating the heat and one on the inside lowering the ambient temperature within inside the cooling box.

    For my first test, I did set the camera to the settings I would be actually using them during my sessions...3 minutes at ISO 800. I then took a dark frame at room temperature (it was actually 70F inside my house) and then I moved the equipment outside and started taking 3 minute exposures with 4 minute intervals and timing and writing down the temperature drop every 15 minutes and here is what I noticed:

    - Temperature inside house - 70F
    - Temperature outside - 50F
    - At 15 min - temperature inside the box dropped to 40F
    - At 30 min - temperature inside the box dropped to 36F
    - At 45 min - temperature inside the box dropped to 34F
    - At 60 min - temperature inside the box dropped to 32F

    Attached are the pictures of the cooling box as well as a dark frame taken at 70F and at 32F in order to evaluate the noise level (both cropped a lot in order to show detail).

    It is clear to me that this is a promising project and well worth it specially in the summer time, but I may have to purchase another ceramic plate that can drop the ambient temperature by more than 20F.


    cooling box 1. cooling box 2. cooling box 3. cooling box 4. dark frame 70F  m. dark frame 35F  m.
    Last edited: Mar 22, 2016
    • Like Like x 3
  2. MadMarco

    MadMarco Mu-43 Veteran

    Oct 30, 2014
    Guildford, England
    That's great, I love what you're doing with the modified camera. Looks like you've got a few hot pixels there, have you tried pixel mapping in the camera (I'm assuming that feature is included in the E-PM2???) otherwise I'd say that is a solid result.

    Next step wound be to disassemble the camera back and place it on the outside of the cooling box! I reckon that would keep you busy for a while ;)
  3. georgian82

    georgian82 Mu-43 Regular

    Jan 17, 2014
    Thanks! It's getting there!

    Yes, there are a few hot pixels here and there for sure. I do pixel mapping once in a while but it seems like they come back pretty quickly :)

    I am not brace enough to open up the camera to put expose the sensor closer to the peltier but I agree that it would be ideal.

    I just purchased another ceramic plate that is supposed to cool down to about 40F below ambient temperature. I will try it next week and do another report.

  4. RenaudVL

    RenaudVL Mu-43 Veteran

    Mar 21, 2011
    Mist that post, very impressive. I remember doing similar project, it is a lot of work and planning to achieve this, congrats...

    How do you get the actual sensor temp, I have tried and could find it in the exif???

  5. georgian82

    georgian82 Mu-43 Regular

    Jan 17, 2014
    Thanks Renaud!

    I tried different websites in order to get the exif data and this is the only one that worked for me: Jeffrey Friedl's Image Metadata Viewer

    You can upload files in different formats. I hope this helps!