Re: Two of a Kind in Leo


Bob Enouen
 


Roland,

Beautiful - Thanks for sharing!  The image quality is amazing.

In your experience, would your highest quality refractor ultimately provide a sharper image than an amazing reflector like this Honders?  I realize there is a huge difference in light gathering between an f3.8 and f8 (1 minute = 4 minutes) or in this case 3’ 20” vs. 13’ 20” for an equivalent f8, but is there another trade off for equal focal lengths?

I have my optimal setup with my Class 5 Bortle observatory based AP1600 non AE (wait listed for AE) combined with APPC Pro, and I’m just planning for the next OTA.

BTW - we were also in Maui a couple of weeks ago and here’s a pic of Dudette that I took while snorkeling off Slaughterhouse beach.

All the best!
Bob



Robert J. Enouen
Cell 513-504-4410

On Mar 13, 2022, at 5:56 AM, Roland Christen via groups.io <chris1011@...> wrote:


https://www.astrobin.com/9rbsjt/0/
This is a preliminary shot, color will be added later when I get a chance.

Skies remained dark and clear here in Hawaii and even with the Moon at first quarter the sky was dark enough to capture some very faint galaxies in and around this grand pair in Leo. The 305 Honders gathers light very quickly so the exposures had to be limited to 600 sec to prevent burning out the cores of the two bright galaxies. 

The secondary mirror on this scope has some schmutz on the periphery which causes the spikiness in the brighter stars. Will clean it some day when I get around to it. I'm not one to obsess about how all the stars look, I'm more interested in how faint it can record stuff in the night sky. Imaging with this scope is a piece of cake. Focus is set and forget with no re-focusing needed after cooldown. It takes about 1.5 hours for the optics to settle down after sunset, and then the images are sharp the rest of the night. 

The 1600 AE mount is run unguided using a 98 point model in APCC-APPM. I usually let it run all night after I go to bed around midnight. We get an occasional small cloud on some nights, which doesn't cause any issue when I go unguided. 

I have imaged with guiding active in MaximDL-6 and one night I set the mount up to shoot a series of 25 narrowband exposures and went to bed. After 10 exposures a cloud must have passed overhead and Maxim lost the guide star. Unfortunately MaximDL is not set up to deal with high resolution encoder mounts (which can go unguided), so it went searching for the guide star. It did eventually find one, but it was about 1/4 degree away from the image I was shooting. If the program had simply turned corrections off when the guide star dimmed out, the mount would have kept the image right where it was supposed to be. Instead I lost the last 15 of the 25 exposures that I had set up for.

Rolando




--
Roland Christen
Astro-Physics

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