Shooting Stars

Add a camera to your scope for cheap astrophotography

By Dave Prochnow Posted 03.14.2007 at 1:00 am 0 Comments

PARTS LIST

2-4MP Digital Camera with a CCD Sensor (FREE)

RadioShack 1 3/8-inch Insulated Alligator Clips (270-1545; $3.49)

RadioShack AA Battery Holder (270-409; $1.89)

30mm Square Thermoelectric Heat Pump Peltier Junction ( target="_blank">allelectronics.com, PJT-5; $9.75)

Heat Sink ( target="_blank">allelectronics.com, HS-130; $.75)

RadioShack SPST Switch (275-0406; $2.49)

4 AA Rechargeable NiMH 2100mAh Batteries 9V Battery

DETAILED INSTRUCTIONS

Build an external battery pack. On models that use regular alkaline batteries like ourOlympus DiMage Z2, this task is relatively easy. This removes a major source of heat from the camera.
Remove the lens. You want to use the telescope instead, so you must remove the factory-installed camera lens. While not that daunting of a task, you must retain the lens and leave it connected to the camera, which can be inconvenient. While building this camera, I managed to break the lens while trying to remove it. Luckily, I was able to salvage the motors and switches-those two unsightly ribbon cables dangling out of the camera body. I had to retain the lens because the Z2's startup sequence "expects" to receive some feedback from the lens (e.g., did the lens extend, is the shutter OK, is the aperture OK, etc.). Without this feedback, the camera becomes a doorstop. So remove the lens, but keep it attached to the camera.
Cool the CCD with a Peltier cooling system. Actually, you'd want this cooler right behind (and attached) to the CCD. The space on this camera made that option impossible. So, I rigged the cooler to the bottom of the camera.
Optional: Remove the IR filter. Most CCDs have an IR filter attached to them. While this filter makes our "regular" photographs look good, a reduction in IR sensitivity can be a handicap for deep space CCD photography. Removing it is easy-it's a little sliver of glass about 3/8 x 1/4-inch in size layered on top of the camera´s sensor. It's easy to lift off of the CCD, as well as drop and lose in your carpet.