Lunar Terminator Thursday 7th August

[Tinderboxsky (Steve)]

Spent about an hour late evening on Thursday exploring the Lunar terminator.

Vixen NA140SS four element achromat at f11.4 (2X barlow to give 1600mm) plus Baader 495 Yellow long pass filter and the SharpCap Chromatic Aberration Correction tool. Good seeing and transparency.

I am now doing all of my Lunar observing using the SharpCap Planetary Live stacking tool - the traditional route of high speed video capture > Autostakkert > wavelet sharpening (using Wave Sharp) that I have done for years is now just too time consuming. I find there is a slight trade-off in the quality of the final image, but that is something I am prepared to live with for the convenience.

Anyhow, here is an exploration of the Terminator on Thursday evening, 7th Aug. The file name lists the dominant key feature in each image. They have lost some sharpness in the compression to fit here.

All images are taken with an ASI178mc camera and are live stacks of 1000 frames (best 15% filter) at 2.11ms each with gain of 300.

Thursday was an enjoyable and productive evening. I completed an EAA observation (with saved image) of each of the 30 targets in The Tasmanian Astro Society's Messier Galactic Bulge Challenge between 8 and 10.30pm. I then turned my attention to the Moon for the attached images and was comfortably in bed by midnight.

[astronobob (Bob)]

Cool views for 1600mm F/L Steve, and your Chromatic Aberration Correction tool seems to perform well on the 140 Achro
Stacking on the fly too, cool as ice...
I think the 3rd, 4th & 5th have a real nice finish to them, smoother and cleaner,, but yeah some my fave craters in there too, good stuff and thnx for sharing

[Saturnine (Jeff)]

Hi Steve , was doing much the same as you on Thursday evening, browsing along the terminator and enjoyed the same views that you have posted, nice images by the way. The seeing here was very good (for here) but was not in the mood to set up for imaging so just enjoyed the visual.

[Pierre_C]

Nice pictures, Steve.

The Vixen achromat seems plenty sharp. What Barlow did you use?

[h0ughy (David)]

some nice captures there

[Tinderboxsky (Steve)]

Thanks, Bob.
Yes, the SharpCap Chromatic Aberration Correction tool transforms an achromat for OSC imaging. One needs a fringe killer or yellow broadband filter to remove the worst of the colour fringing at the UV end of the spectrum to make it work. The NA140SS, especially at f4, is now my EAA workhorse after having been my main visual scope for many years.

Originally Posted by astronobob

Cool views for 1600mm F/L Steve, and your Chromatic Aberration Correction tool seems to perform well on the 140 Achro
Stacking on the fly too, cool as ice...
I think the 3rd, 4th & 5th have a real nice finish to them, smoother and cleaner,, but yeah some my fave craters in there too, good stuff and thnx for sharing

[Tinderboxsky (Steve)]

Thanks, Jeff.

Eyepiece views of the Moon, planets and deep space over many years are etched in my memory banks. I have traded these for deeper EAA views - all of my observing is now using the NA140SS plus planetary camera.

I have the rig permanently assembled. All I need to do is power everything up and I am ready to go - virtually as simple as visual used to be for me.

Originally Posted by Saturnine

Hi Steve , was doing much the same as you on Thursday evening, browsing along the terminator and enjoyed the same views that you have posted, nice images by the way. The seeing here was very good (for here) but was not in the mood to set up for imaging so just enjoyed the visual.

[Tinderboxsky (Steve)]

Thanks, Pierre.

The Vixen NA140SS was my primary visual refractor for many years - I was lucky enough to get one of the first new versions when Vixen returned full manufacturing of these to Japan in 2015. They put a lot of effort into getting the quality control right and it shows with exceptionally well figured sets of lens - a doublet objective and a second doublet just forward of the focuser, very similar in design to a petzval. It produces a well corrected flat field. These are very under rated visual scopes, probably shunned because of their “achromat” label, rather than “apochromat”.

It has been quite a journey to get this working as an effective EAA rig. It would not have been possible without the SharpCap Chromatic Aberration Correction tool. The new Star Colour Calibration Tool has improved the outcomes even further.

I have three different image trains set up for my EAA observing:
F4 (560mm) using Vixen focal reducer
F5.7 (800mm) native focal length
f11.4 (1600 mm) using Televue 2X barlow.

Originally Posted by Pierre_C

Nice pictures, Steve.

The Vixen achromat seems plenty sharp. What Barlow did you use?

[Tinderboxsky (Steve)]

Thanks, David.

I enjoy your “Lunar Lunacy” posts.

Originally Posted by h0ughy

some nice captures there