Doug The SC3 does not appear to be holding focus. Having focussed the telescope and then having focussed the SC3, its fine for a night or two, but now having focussed the telescope, I can move the focuser a few hundred steps and get a much better focus on the SC3. There is no locking mechanism for this is there? Or are we talking tape. Martin
well, happened again tonight...I had the support guys focus the SC3 (having first focussed the scope), then I slew to the target, started to guide with the AO and I could see it was out of focus. Moved the telescope focuser by 600 counts outwards and it came to focus. So had to get the guys to push the sensor out by about 1/2 turn. A focus lock would have been good....plus the 10bit sensor is horrible.
Could it be that the telescope is simply drifting out of focus with temperature? The pixels on the SC-3 are fairly fine - it might be more obvious when the telescope is out of focus than the main camera, if its pixels are much larger.
