Hi, A black stain appears on the left side of the star. A black stain is so faint that it is hard to see in the original one frame. What is the problem? STX-16803 180 sec x 10 frames combined.
Years ago I made a minor improvement to the DC restoration circuit in the STX to reduce this phenomenon. If it's old enough it might not have the mod. What is the serial number of your camera?
That is quite old. There's a simple mod we can do to improve that behavior. If you would like to return it for service, please fill out this form: http://diffractionlimited.com/request-rma
