Last night was a beautiful night, so I tried some more testing.
First, I reran the flats for the Canon using a target of 5000 ADU instead of the original 20000. Ran a number of M82 shots. The bin1 shots seem to be doing the flat correctly, but the bin2 images are still dark in the center.
Then, I saved the Narrow system setup and started getting the Wide system working. A lot of things have changed, since the cameras are switched from the original setup. The VCurves are still valid.
Basic problem: the filters aren’t working on the SBig. I will need to get that fixed. It also seems like the internal guiding function isn’t right somehow. I will need to look at that.
Tried doing some 5 minutes exposures to check guiding using the external guider. Guiding is working well, stars look good.
Tried doing the 5 minutes without guiding (ProTrack and PEC should work, right?). The stars are elongated in RA. Looking at the guiding graph, there is significant fluctuation in the RA, perhaps +/-3-4 pixels. If the image scale is 3.7 arcsec/px, then this is a fluctuation of 12 arcseconds – not good.
Tried again with PEC turned off. This is better! although still +/- maybe 2.5 pixels. Remembering that I had randomly flipped the PEC because I thought it made it better, I re-flipped the PEC curve and tried the flipped version. I think it looks better. Portions are very nice and flat, but there is a section where the graph wanders up and then back down again.
Summary:
– Need to fix the filter wheel. I assume this is the UHC filter falling out again.
– it looks like I need to re-run the PEC curve, see if it looks any different.
– Need to check the flat process with the Canon. Something is still wrong there.
– The system still does not point accurately. It looks like it needs to be sync’d on some star to be correctly centered. Slewing to targets puts them off to the left of center. On the Canon, the target can be off the chip, off by 10-15 arcminutes. Certainly not the 6 arcseconds being reported by SkyX.