K3PGP - Experimenters Corner

During one of our typical overcast nights I just happened to plug two of the cameras in and point them at one of the telescopes with the lights turned off in the room. The only light was coming in through the cracks around the window blind (so much for dark skies!) and what was bouncing down the hall and entering through the open door. I could NOT make out anything in the room when I looked around naked eye even after several minutes of sitting in the dark room so it was indeed quite dark! I knew there was a difference between these cameras but up till now I never took the time to try them side by side looking at the same scene under the same exact illumination. The difference was even more striking than I could imagine between these cameras so I went and got the third camera to see how it compared to the other two. The real surprise was the $120 Super Circuits PC-164! Although not the most sensitive camera of the three, it offers an incredible amount of performance for the price. All images below where captured under identical conditions. 10 frames were captured and summed to produce the single image which is displayed here. This was done to average out any difference between single frames as digitized by the computer. No attempt was made to enhance the video in any way. What is shown here is as close as possible to what the output of the cameras looked like on a video monitor.

Polaris DX-8263SL $250	The $250 CCD camera from PolarisUSA Video, Inc. is the only color camera in this comparison. Unfortunately it is also the least sensitive camera even with the integration set to 128X. With the integration set to 1X NO PICTURE could be seen. Also note the excessive number of bad pixels. Of course given more light this camera produces excellent pictures. However, if your goal is to image dim objects or you have a long FL telescope or lens then this is NOT the camera for you. It is at it's best when used with fast lens under f/2. It will do a decent job of imaging the brighter planets with most any scope including the ETX series. But it is NOT the right camera for deep space objects unless you have a very fast (short focal length) lens or telescope in front of the camera and even then may prove dissappointing. However, it does make a decent color camera for aurora when used with a short FL (2.8 mm) F1.4 lens.
Polaris DX-8263SL $250	The DX-8263SL camera with the same scene captured in monochrome. There is a monochrome version of this camera which is more sensitive. However, since I do not have one it is not included in this comparision. I'm told by several that own one that it is NOT as sensitive as the Mintron shown below.
Super Circuits PC-164C $120	The Super Circuits PC-164C is quite a performer at $120. If you don't mind spending the extra time required to capture several hundred to a thousand frames when imaging extremely dim objects then then you can save some money by investing in this camera. It will easily outperform the DX-8263SL provided of course that you do not need color. There is a color version of this camera which is not compared here but keep in mind the color version has drastically reduced sensitivity. NOTE: This camera is sensitive to power supply ripple. The horizontal bands are being caused by inadequate filtering of the DC (wall wart) power supply. The same power supply was used on the other cameras without any problem. If you use a PC-164C make sure you feed it pure DC! When doing long term integration of many frames of video, defects such as this will cancel out so it's really not an issue even though it's easy to eliminate.
GMV-EX6K / MINTRON 12V1E-EX CAMERA $529	The Mintron 12V1E-EX as sold by Resources Unlimited is the most expensive camera campared here. However, as you can see the extra money buys a phenomenal increase in video quality and sensitivity. If you have a long focal length scope or any of the Meade ETX scopes then you will need every bit of the sensitivity that this camera has to offer! Keep in mind I could see absolutely NOTHING when looking at this scene naked eye!!!

All of the above cameras produce excellent quality video given sufficient light. What is being compared here is the ability of these cameras to produce an image under extreme low light conditions. When the light was further reduced to the point where the image just started to show some noise as viewed through the Mintron 12V1E-EX the other cameras produced NO IMAGE at all, only noise!!! The Mintron is worth every penny !!!