K3PGP - Experimenters Corner - DX-8263SL Color Camera

Saturn 12-28-04 ~10:20 pm
Just below near full moon
Camera in 2x zoom mode
at prime focus of ETX-125.
Obviously more magnification is needed!

Single frame from 11-24-04 VIDEO
Quality of video degraded by
compression. Grain is from moonlight.

The Polaris DX-8263SL is similar to the GMV-EX6K / MINTRON 12V1E-EX CAMERA and the DXB-8200SL but is the color version. It has nowhere near the sensitivity of either of the monochrome cameras but has the advantage that full color photographs and video can be recorded without having to make use of RGB or CMYK color filters. Unlike the monochrome cameras which use a 1/2 inch CCD, the DX-8263SL uses a 1/3 inch CCD and is the cheapest in price of all three. It appears to have a built in '-green glass-' type IR filter which I am not particularly fond of but this should eliminate the need to use an IR blocking filter on most refractors. However, it proved insufficient to completely eliminate the IR problem when using my Fujinon 16-160 mm lens and I have to use an external IR blocking filter on this camera when using the Fujinon lens. Although I have removed the internal '-green glass-' filter from some other color CCD cameras and installed a better filter, I have not tried doing this with the DX-8263SL at this point.

So far light pollution appears to be the limiting factor at my location when using the DX-8263SL with a fast lens ( f<2). However, this is NOT the case when using a longer focal length such as a telescope where there is no substitute for the MINTRON 12V1E-EX camera. This would most likely still be the case when using a fast lens at a dark location. Although the monochrome DXB-8200SL looks the same as the MINTRON 12V1E-EX camera, it does not appear to have anywhere near the same sensitivity. I hope to document side by side comparisions between the cameras that I own. (See CCDCAMERAS!)

As usual it has been overcast here (Weather) and the first break in the clouds since I purchased the DX-8263SL occured approx. the same time as full moon which of course made the sky look like daylight in the first VIDEO I was able to shoot even though it was in fact quite late at night. The first scene was shot using an 8 mm f 1.2 lens followed by a 4 mm lens. The rest was shot using a Fujinon 16-160 mm f1.8 zoom lens. All shots were taken from an unstable consumer type TV tripod. A lot of the detail in this video was lost due to the compression to get the filesize down.

For information on remote controlling the switches on this camera see DX-8263SL Remote Control.

Feb 06 2005 1:30 am

DX-8263SL CCD camera set up as a widefield polarcam. This configuration is usually used for viewing auroras and consists of a 2.8 mm f/1.4 lens. The photo at left was taken with the camera in manual gain mode set to the center position. White balance was also set to manual with all controls in the middle position. Integration was set to 128x. The DX-8263SL produces continous '-real time-' video that updates approx. every 2 seconds when in this configuration.

Matching this photo up with a star map generated by Cartes du Ciel shows considerable stretching of the image in the lower left and right hand corners of the photo. This is to be expected with most very short focal length '-fish eye-' lens. The two images were aligned using Polaris and the pointer stars of the Big Dipper. The distortion gets progressively worse as one deviates from these stars.

There is a slight focus problem visible in the lower left hand corner of the image as confirmed by Cassiopeia. I suspect the lens may be tilted very slightly with repect to the front of the CCD. This becomes extremely critical as the focal length becomes shorter. I intend to look into correcting this next time I have the camera in this configuration.

The red glow in the lower part of the image is due to a small aurora and man made light pollution blending together. The little dipper and some stars down to approx. magnitude 5 are visible in this photo. This is better than what I could see naked eye and will probably improve a bit once the focus issues are resolved. Not too bad considering the light pollution and the fact that a 2.8 mm f/1.4 lens is a very tiny piece of glass. Unfortunately comet Machholz which is visible in this photo just north of Cassiopeia (The greenish '-smudge-' about the same distance as the two northern most stars and in the same direction.) was pretty well buried by the aurora and light pollution as it was low in the sky at the time this photo was taken.