Revised 3/2023:
Not much to say here.  Added a few subs to the total.  And I did not have the full suite of RC tools at the time, so the stars are improved.  Though the corner stars are an issue since I had not figured out the tilt or backspacing yet.  I think I got the color better on this.  A less agressive stretch and blackpoint from the last "final" version.

Original Description:
This is first light with my new TS Optics UNC f4 305mm Newtonian.  I ordered it about this time last year and it slowly arrived throughout the spring after a number of issues.  In the meantime, I have been dealing with health issues as well.  But during the intervening time, I have been playing with getting the setup working and refined indoors when I could.  But not to dwell on that stuff...

Image: 
I will start with the image description here.  After this section, below, you can follow my journey with setting up this telescope and the details and problems with the image and its processing.  NGC 7331 has been posted very many times on AstroBin, with many fine discussions that I will let you follow up on Wikipedia.  Here it is presented along with Stephan's Quintet as a nice pairing.  As a first light image, it is presented as it fell on the sensor after screwing on the camera.  I was concerned with other issues and was lucky that the orientation is not far off from what would be viewed if one were looking due north and up.  One only needs to imagine a rotation of about 45 degrees clockwise to be perfectly accurate.  In these orientations, the view of 7331 is not at all favorable for the purpose of scrutinizing this galaxy.  I plan to post another on here of a crop and slightly differently processed image of this galaxy to better effect.  But the new post will be warrented because I have some ideas that conflict with what has been said of this galaxy in the past.  I used Photometric Color Calibration and believe that the colors presented here are true to that outcome.  I did no specific color shifts, but did enhance saturation.  I love the billowing clouds of blue stars dissected by darker dust lanes or just maybe empty (or dimmer stars not visible to my scope) that seem concentrated to the outer zones of the galaxy.  I am also pleased to see these dotted with small pockets of pink HII zones.  Yes, less dramatic than if I added HII data, but truer to reality, I think.  I did damp down the stretch in the center-most zone to bring out detail and the stellar core, but did not depress the much fainter bulge that can be seen above and below the central ~1/4 of this spiral.  There are a number of satellite galaxies visible in this image.  Some may require going to my less black point revision to see them.  But PGC2051985 at 10 0'clock is the most prominent and is also known as M.  I invite you to find @Gary Imm 's fine inverted image showing these in detail.  Depending on your monitor, the revision may better show that M is a distorted galaxy with substantial broad star field extensions that extend outward from the denser central region that is most noticable.  I found a paper that simply confirmed this.  I couldn't get the full paper to find out what they thought was the cause for this distortion, but I will guess or propose that M had a relatively close encounter with 7331 in the past.  Remember that...  7331 is 130 thousand light years in diameter.  The size of the Milky Way.  The other distinctive galaxies apparently nearby are far behind 7331.  It is often stated and repeated that the core of 7331 is displaced to one side.  I have measured this and fail to find the displacement.  Maybe if one uses the brightness of the limbs as a measure of mass, then maybe, but not to the extent of the limbs.  I do find there seems to be an apparent displacement forward, but this may be an optical illusion.  What I do see is a dramatic warp in the disk.  I propose that the large outer forground arm lifts above the general plane of the galaxy as you follow it north and even after it descends.  (A reason the center seems displaced forward.)  This is something discovered to exist in EDIT: (strike "the Milky Way") our neighbor the M31, the Andromeda Galaxy and what I found to be plainly obvious years ago from the many photos of our sister galaxy.  Would it not make sense that a near interaction with M might not have caused this?  I would not expect a collision occurred, but rather close enough for the two galaxies dark matter halos to impact the other?  My next posting

NGC 7331, Is the Center Displaced or is the Disk Warped Similar to the Milky Way?
with the cropped reoriented image of NGC 7331 will have a more detailed discussion on the warp.

I am pleased with what I see of Stephan's.  It is not in the most favorable part of the image (see below regarding coma, etc.) but I clearly can see more than I did with my image with my RASA 11.  (My processing was horrible at the pixel peeping level, so...)  I am also happy to see that I captured the faint blue star stream descending from NGC 7320.  This is typically not seen, or shown on astrophotos.  But it is interesting and curious.  The tail extends almost to the small circular barred spiral.  But all these galaxies visually close to 7320 are around 8 time distant as 7320 is to us.  In fact 7320 is essentially at the same distance as 7331.  These two galaxies are roughly 340,000 lyr apart, so relative neighbors.  Could the star stream been generated by a rapid flyby of 7320 past 7331?  Or maybe by one of 7331's satellite galaxies?  I can't find information on the direction of motion for 7320.

First Light:
For those of you that have followed my postings over the last year or so, you will know that this rig was purchased with two capabilities in mind.  First and foremost was for the use of photometry, particularly in a dual band (2 camera) setup, with VIS and NIR.  I will post in the near future of the struggles that I am having with that setup and show the progress.  But also, I wanted to be able to use this to do some aesthetic imaging.  (In rare cases, I would also love to look through the eyepiece through this as well.  But this first light was clearly an imaging session.  I chose this mode because I was concerned that I might not have the backfocus necessary to do decent astrophotography.  I can confirm that I was able to get enough backfocus to stuff a coma corrector and a filter slider in the optical train, and allow me room to do an autofocus without bottoming out my focuser.  This bodes well if I ever get a filter wheel.  The large OTA is still rather light and the CGX-L handles the weight well.  I will go into more detail on the rig in my NIR post, since I will have photos of gear.  But the OTA is a kite and wind will be an issue.  The goal is and was always to get this under cover of an observatory and on a mount better suited for photometry.  If you must see a photo of the OTA as it arrived please see my last posting at

New Telescope Service UNC 305 mm, F4 arrives! First Light to be Delayed for Unexpected Reason

For first light I really had no expectations of any success in imaging, so chose a target that I knew would be available the whole night and reach a rather high altitude for sky clarity.  So I chose the pairing of NGC 7331 and Stephan's Quintet.  The framing angle is as it showed up after I screwed on the camera.  I got lucky because I have no rotation option.  I had set up the telescope up almost completely indoors so that I was sure all the systems worked together.  I have added a Pegasus power unit and along with the NUC these all mount on a Losmandy dovetail just behind the tracking scope.  Cables are all short and I got rid of a lot of power bricks.  Only one custom made 12V power cable to the Pegasus and another light flexible usb printer style cable to the mount for tracking.  Comunication to the NUC is via wifi over about 100 ft distance.  All this and the rig is still pretty light!  And great balance achieved.  For backfocus, I had given myself some edge by having adjusted the primary mirror forward to the extent that the collimation screws allowed.  It worked.  The Pegasus has an adustable power out port for DSLR use.  I appropriated that to run the primary cooling fan.  A nice bonus.  NINA interfaces with Pegasus under Switch and I believe that I could probably program the fan speed to react to sharp changes in temperature, or at the very least turn off or down after a certain time of night.  I had collimated the scope in the house a few weeks ago, but did not want to spend even the few minutes going down that path this night, so after my wife and I carried the OPT setup out to the mount, I just connected power, balanced the rig and did a three point model to get me indoors.  Polar alignment was of course not perfect, so I redid a 6 point model on CPWI when I got indoors.  This was so efficient that I got done just about the time decent imaging could be done on the target we see here.

I have done this target in the past with my extra wide field RASA 11.  The 12 inch was supposed to deliver a longer focal length, better for these smaller things, however it is just 2X the f.l. and for some subjects I may Barlow to gain some additional reach for artistic astrophotography of smaller objects.  But I could not sustain a long f.l. OTA because the sensor of my NIR camera is very small as it is and would be too limiting.  So I think I guessed well with that.

Before I tear apart the image I present here, I should say that I am very happy with the general performance of the setup mechanically, electronically and optically, so far.  The image field is certainly smaller than what I achieved with my RASA, but I think the data exceeds in quality that of the RASA as one might expect, with some important exceptions.  First I should say that the pixel scale with this camera is better suited for the 12 inch.  And the purpose of the RASA is as a widefield for overall impact.  But it is the failings that I think exist in this first session that leave me hopeful that I can gain significant improvements in the future for this type of imaging.  Some of the following, you cannot fully appreciate because my failings in processing have introduced more artifacts!  But here goes: 1. Even though I measured the backfocus of my image train carefully and tried to account for the LP filter, I still have some coma.  The glass elements of the CC in this case can cause color separations as seen in uncorrected refractors.  (Reflecting-only scopes with no intervening glass elements do not generate this color artifact.)  2. The fact that the coma is not perfectly centered tells me that my secondary mirror is slightly rotated.  This likely contributes to the color I saw in some of the stars even within the part of the field that was not strongly coma'd!  It better be, because the only other explanation is that CC sucks.  To me, getting the exact rotation of the secondary is one of the hardest parts of collimating a Newtonian.  3.  I have only the very slightest vignetting.  This too confirms the rotation in the secondary.  Mostly, this confirms the suitability of my 83 mm secondary for illuminating a C-sized sensor.  I have a smaller one (63 mm) for my photometry and a larger one (100mm!) if I ever decide to dedicate this scope to imaging on a full-frame camera.  4.  I see no signs of tilt or flexure in the optical train.  

On to processing:  A lot has changed over the intervening months of my illness and my last attempt at processing astro data.  So here, I tried my hand at some firsts, within the PI environment.  I had used StarXTerminator before and liked it, but I employed the current AI for the purpose star reduction using Bill Blanshan's pixel math expressions for the first time.  Wonderful!  Time savings appreciated.  I also set up NoiseXTerminator and found it to be great.  To quote another, "It just works".  Its detaill function is very intriguing.  I employed it here to good effect and also bad.  The bad can be seen in many stars that have artifacts that seem to have a off-colored squiggly line through the stars.  This is something that Russell Croman clearly states in his product discussion and I only forgot to strongly mask the stars at the time I tried this function for the purpose of enhancing detail structure in the galaxies.  So my bad!  But I am amazed at how well it works at doing very gently structure enhancement that appears completely accurate.  It allowed me to skip doing deconvolution entirely. and it was a one click action.  (Well, I actually employed noise reduction weakly several time during the processing.)  In addition, the stretch of the final image takes a pretty deep cut for the black point.  I know that some do not like that, but I was left with some periodic horizonal noise that I failed to notice until too late.  And this was a first light with other objectives, so taken together with the star defects, I will not redo this image, since it looks fine at normal viewing scale.  I have found with this camera that I can get such noise with the camera usb setting not set correctly.  At 60 sec subs at 0 gain (I wanted zero saturated stars), this can pop up.  On the other hand, the PI Weighted Batch Preprocessing has changed so much, I may have set it up poorly.  In any case, if you want, the revision is less clipped.  However, I will state that even with the agressive blackpoint in the final image, we can still see the faint blue star trail that extends from NGC 7320 to almost PG 69279.