NOTE: Repost of an evaluation I posted on the AP forum.
After weeks of typical Pac NW crap weather I got the system calibrated and tilt adjusted and a model and all the other prep. I selected double cluster since it was quick and I wanted to do optical evaluation. Not exactly Astrobin level for a final image - that will have to wait for summer - but plenty good for evaluation.
The initial look at the monochrome RGB and Ha bands in the individual frames seemed to show slight elongation in the corners but I went ahead and did flats and darks and calibrated and combined them. Roughly 25 frames per band, 60 second unguided RGB and 600 sec Ha, also unguided (not shown here). The 1600 can handle the 155 unguided, which is nice.
The results you see have been calibrated, registered and combined using Normalize Scale Gradient and the gradient from our nearby small town removed with Graxpert and then histogram stretched and noise reduced. There was no aberration correction or other processing of any kind. The apparent slight distortion had vanished, despite still being present in the mono reference frame (and the rest of the subframes). This was true for all bands. Dynamic PSF showed all stars in corners and center round at over .89 for all I checked (and most were higher).
This is truly the best I have ever seen from any of a fairly large number of refractors I have used in 30 years!
📷 Ab Inspect 155 RGB.png
