Light frames appear to be normal. A .4 sec dark is all saturated in 1x1, streaks in 2x2. A .4 sec light is normal pattern in 1x1 and 2x2. Same for longer lights. Tight dark cap over front of OTA in both cases. I believe there are no light leaks and the shutter is working properly. I'd be happy to do a TeamViewer (or whatever you use) session to show you. Jim Sgt