Filter Light Leak

Telescope Kitt Peak 0.9m
Date 1/22/1993
Instrument t2kb
Filter H alpha
900 s
Other Image not processed.

Suspected Problem:

The scattered light visible all over the image is most likely due to a light leak in the filter wheel. When the filters were put into the filter wheel, the outside was not covered with black tape, thus allowing extraneous light to hit the CCD.

The stellar reflections (rings around the brighter stars in the image) are probably due to internal reflections in the filter. This can occur when the filter is inserted upside down, but should not happen when the filter is inserted correctly..


Make sure no unwanted light can get into your setup. This frequently means taping up all the potential light leaks with black tape. And obviously take care to properly insert the filter into the filter wheel (frequently done by telescope personnel).

Return to the Main Directory

See example of light leak in camera

Return to the "Other Features" Directory