Here is rescued data.  To my wife's chagrin, I finally succumbed to the relentless ads from the ASPCS, the American Society for the Prevention of Cruelty to Stars of which I felt duty bound, since I was the one who did the damage.  See as follows the pre-BXT stars:  In my attempt to put into use the Sigma Art 105mm, F1.4 beast of a lens this summer, much bad data was collected.  Try as I might, never getting decent stars.  I have already posted one image from those sessions from the best of the data after much struggle to get the backfocus and tilt corrected.  All signs were that I was not going to succeed with this lens/camera combination so I returned the rental.  After another weekend of testing, I moved on and decided to work with the better known Rokinon 135, which at this time remains idle for lack of sky.  At the time, I made serious attempt to process the data.  No luck.  Since then, the real saviour, release 4 of the BXT AI, gave me a chance to see what it really could do.  As everyone has learned, nothing short of a miracle.  Still, not perfect.  I may have a couple more of these 105 mm data sets to rescue, so stay tuned!

Given that most of the horrible star defects were negated or reduced, it allowed me to process this image as I have been doing most things lately and I was pleasantly suprised at the result once again.  Especially with only 1hr 47min integration.  Can't beat shooting at f1.4!  All 30 s exposures using an enhanced gain setting that yielded the lowest camera read noise, moderate full well and a very high dynamic range.  Similar conditions I used to capture parts of this area with my RASA in:

The Perseus Molecular Cloud, Omi Per to NGC 1333 and Beyond. A Mosaic  Still, if this lens was in my collection, I would be looking to gather more time on the subject. 

In keeping with the aesthetic of my more recent wide field, OSC images, I have tried to emphasize the non-emissive molecular cloud complexes, which necessarily deemphasized the California nebula.  This only required a small bit of masked stretch to not blow out the CN in the last step of the processing.  The framing is a bit weird, since this was a planned panel of 10 that I want to gather to mosaic into a larger project.  Even with a slightly cropped C sensor, 105 mm yields a very healthy field of view!  Plenty of room to hold the CN and yes, the blue arcs in the lower right corner, resembling the outer bands of an approaching hurricane on a weather photo, are the outer reaches of the Pleiades!  My favorite, the colorful bubble near Omi Per is partially visible and there are other AstroBin favorites seen as well.  The star of the show is the California Nebula.  With all the defects seen at close range, if nothing else, I hope that this image impresses as to how the CN is related to the surrounding molecular cloud complex.  The CN is likely just the same as many of the other clouds that it is clearly connected too.  What is exceptional, and what excites the gases in this part of those clouds is the bright O7 star Xi Persei, or Menkib, seen tucked closely within the curve of the brightest part of the CN.  Likely the fainter H alpha signal scattered to the right of the CN is molecular/gas that is behind Xi Persei at a distance that reduces its brilliance.  But I cannot be certain of that.  Then the non-emissive clouds surrounding the CN logically should be in the foreground from our perspective.  Un-illuminated because of distance from a hot star?  I stuggle with this because I keep seeing un-illuminated clouds that clearly are very close to very bright, energetic stars.  Omi Per is a prime example of this, with several hot stars stuck right within a cloud!  Yet often these relationships seem to generate only reflection nebulae, at best.  What gives?  I wonder if these molecular clouds are not compositionally much more varied than we are lead to believe from the common astronomical press?  Are these "dark" clouds just devoid of gas?  Is there sorting of gas from dust that commonly occurs?  To confound those ideas, it appears that many of these dark, non-emissive clouds are rife with star formation.  So clearly there is hydrogen there.  Maybe there is a dramatic effect of the concentration of dust, when mixed in with the hydrogen, that prevents UV from reaching the gas, rendering it non-emissive?  Stuff to think about...

In any case, at some point in the future, the hope is to put data like this into a large mosaic of the Perseus/Taurus molecular complex, at 1,000 ly distant and a neighbor that seems prone to form sun-sized stars in abundance.  A job for my 135!