This is 6 hours of exposure data on the Heart and Soul Nebula, extreme wide-field.

Frames are 120s, f/2, ISO6400

Optolong L-Extreme Filter was utilized to accentuate Ha signal

(To adapt Samyang 135 f/2 to 2" filter use a 77-49 and then a 49-48 step-down. You can still shoot full frame, even wide open)

[fotofile]

Great shot. Lots of work went into that!

Q1: Of the 180+ frames that took, how many had to be tossed due to Starlink, airplanes, etc?
Q2: Curious about what's the effective f/ stop with your setup? e.g. around f/3-f/4 ? 135mm f/2 has about 67mm aperture; reduced to ~45mm for the 2" filter clear aperture.

Those are great questions. For the first one, I'll break it down a bit. The six hours is an estimate, because I'm really not done; I want to get up to 12 hours total for this one. That was the goal anyway; I might call it good after 9, as that tends to be my MO, lol. Anyway, I have taken WAY more than 6 hours of images for this. I think I'm at 5 separate nights with various time allotments. I manually review each RAW file and reject any that have obvious tracking issues or artifacts from man-made objects. I would estimate that fraction of rejects to be pretty high, but I don't log them. It's probably between 1/4 and 1/3 of all exposures. Then I stack in DSS using separate groups for each night's lights and flats. I also let DSS cull frames automagically, and I decrease the number of frames accepted by 5% for each group, (night). I'm willing to lose a few extra each night in the name of added precision, because I'm adding significantly more than 5% frames and I want to be sure to reject any outliers my eye didn't pick up. Whenever I decide to be done, I want to be around maybe 70-75% acceptance; I'm thinking I will probably run a second stack at 90% and see if there is a substantial difference in quality.

For your aperture question, oddly the lens has a 77mm front filter ring, butI did some research and some other nerds have found the effective focal length is closer to 130mm and the entrance pupil measured with calipers is 64.85mm = F/2. Regardless, it's being brought down to 48mm by the filter, (they call it a 2" filter, (but it is attached to a 48mm step down ring, so I feel like that may be a more accurate way to judge it), so I would say 135/48=2.8, or even 130mm/48 = 2.71

---------- Post added 12-29-21 at 09:00 PM ----------

Wonderful shot, What tracker did you use? Astrotracer or something else?

I'm using the Skywatcher Star Adventurer. Thank you!

---------- Post added 12-29-21 at 09:01 PM ----------

Excellent image; 6 h exposure certainly paid off

Thank you! I'm still working on it