It doesn't Bode well for the new flat...

This latest test of correcting the collimation of the AT8RC demonstrates that it will produce a virtually coma-free image as seen in the image of M81 (Bode's galaxy) below. This is good! However, I screwed up on creating the new flat. My white sheet apparently got loose and I left the camera on high gain (1600 ISO) rather than 100 ISO where it was supposed to be. Doh. Before post-processing, the imaged flat was not what I was expecting. Ran the image workflow anyway just to see. Need to remake the flat.

I suspect though it may not help much as that even with a marginally imaged flat, the previous addition of the field flattener had significant impact on post-processing out the uneven signal levels due to optical curvature.

So, before reverting back to using the flattener lens, I will take another round using a deep sky filter for comparison.

Collimation step two...what step two?!

Waited almost an hour for scope to cool down outside this evening. For the optical star test, all the provided extension rings needed to be added including a 2" eyepiece extension. Three-star aligned scope using the 1.5" insert and both a 15mm and illuminated reticle piece. Tracked on Sirius to conduct test. It is a wonderfully clear night, again.

Looked just fine. Nice round concentric circles. No warping as focused in and out. Pin point focus also provided sharp diffraction spikes across the entire field of view. Very nice.

Started taking shots of M81 without the field flattener. Have to say, the brighter image seen in the test shots was pleasing. No filter either, we'll consider this a test run on the new collimation.

Need to remember to not remove camera until after I've been able to create a new flat with this change to the optical configuration