Koehler Urban Astrophotography

02/18/2024 -- With clear skies but a giant moon overhead, after some initial experiments with a Nikon Nikkor 300mm F4.5 IF ED AI-S Manual Focus Telephoto Prime, decided to get out the vintage Jason 700mm F11.6 singlet and test it out with the Panasonic Lumix GH5 attached to the business end.  Used the incredibly bad Celestron CG-3 just to hold the scope in place using the vixen dovetail on the OTA. Results from stills (edited in digikam):  And a video edited in Davinci Resolve 18.6:   02/19/2024:  Repeat on a second night.  Found counterweights and other parts for the CG-3.  What an awful mount...no idea why I'd purchased such a terrible piece of equipment.  But basically as a fixed mount with a lightweight OTA and no wind...it's fine.  Skies were similar to last night...cloud free. Seeing forecast from meteoblue for 02/19/2024 With counterweights and knobs on the mount, centering the moon and positioning for photos and video worked far bette...

 12/14/23 - With clear skies and no moon, created a 3x2 mosaic in the Indi/Ekos scheduler for M45 using the 8" LX10 EMC SCT with the new Sv405cc and 0.63 focal reducer and the Svbony UV/IR filter.  Initial polar alignment was waaay off -2500"... re-positioned the whole mount in several steps before getting lucky and sticking the alignment at ~4".  Given a forecasted low temperature of about 28 F, set the camera cooler temperature to 25F (-3.8 Centigrade).  Left the camera gain at default...which is a gain setting of 10. Focused with the Bahtinov mask...with only minor adjustment (half a turn). Forecast for 12/14/23 from Cleardarksky Seeing forecast from meteoblue for 12/14/23. Tested 180s collection...settled on 120s x 30 per tile in the mosaic.  Guide errors were reasonable at <4". Indi allsky sky quality metric for 12/14/2023 Indi allsky star count for 12/14/2023 From this collection, obtained 88x120s light frames total (before tossing out poor collections ...

11/12/23 - Started collection against M33 / Triangulum galaxy with the LX10 using the 0.63 Meade focal reducer, no filter and the SV405cc. Mount has remained unmoved for a week out on the deck. Double checked polar alignment using PHD2 on the Odroid XU4 and found nominal alignment (~6") and checked focus with the Bahtinov mask. Forecast from cleardarkskies for 11/12 showing great conditions. Forecast from meteoblue also suggesting good conditions (with the exception of seeing). Bahtinov mask collection after adjusting focus on 11/12/23. Initial M33 result from AstroPixelProcessor using the first 54x120s (6360s, 1.7 hours) of collection. 11/13/23 -- set the scheduler to launch collection against M33 automatically starting at ~18:30.  This ran through one complete job (60 light frames) which lasted approximately two hours (18:36 - 20:49).  Restarted collection on an additional 60 light frames at ~22:18.  Forecast for 11/13/23 from cleardarksky suggesting cloud-free, dark sk...

11/3/23 Starting a new target: IC 5146 is a reflection/emission nebula and Caldwell object in the constellation Cygnus.  Clear dark sky forecast for 11/3 showing clear skies until around 3am with average seeing. Astronomy Seeing forecast for 11/03 from meteoblue showing the arrival of peak clouds around 2am. Given the radius of about 1 degree, using the Meade LX10 with the 0.63 focal reducer with the dual narrow band Ha/OIII filter with the new Svbony SV405cc OSC camera... with an expected low temperature of about 40 dgrees F, set the camera temperture to -5c.  After finding good focus on the Celestron 9x50 RACI finder with the ZWO ASI120MC-S, started with a rough focus on Sadulsud (Beta Aquarii) with the priimary OTA.  Then began polar drift alignment...initially way off at -1200" (ouch) (pre-meridian flip).  Tightened on the right side of the mount (facing the front). First adjustment: -700".  Then -200. Over-corrected on the third adjustment with ~100". ...