Mewlon meets Moon – comparison between x1.6, x2.0 and x4.0 Extenders.

[Dennis]

We enjoyed some moments of steady seeing in Brisbane last night, (23rd Sept 2018) and whilst cruising the almost Full Moon with my Tak Mewlon 210 F11.5, I thought I’d have a crack at seeing how far I could push the image scale using the following combinations:

Tak x1.6 Extender. (efl 3864mm at F18.4).
TeleVue x2.0 PowerMate. (efl 4830mm at F23).
TeleVue x4.0 Powermate. (efl 9660mm at F46).

The camera used was a ZWO ASI 174 MM, with FireCapture and set to record 4,000 Frames for each AVI.

Workfow.

AutoStakkert!3 to select the best 33% and Align, Stack and save as TIFs.
Open each TIF Registax and apply the same Wavelets Settings.
Open each TIF in PS CC and crop to 1024x1024 at full resolution from the 1920x1200 image.
Process each file and save as JPG.


I was very pleased with the performance and image quality using the Tak x1.6 Extender and TeleVue x2.0 PowerMate and I honestly did not expect to obtain anything more than mush with the TeleVue x4.0 PowerMate, but was pleasantly surprised with the results, albeit soft and fuzzy.:)

I have included a Plato image at with the x4.0 PowerMate which has managed to reveal several of the smaller craterlets on the dark floor.

Cheers

Dennis

[RickS]

That's amazing, Dennis :eyepop:

[FlashDrive]

That's excellent :)

[Atmos]

Incredible images Dennis!
Did you prefer the Tak extender or 2x PowerMate?

[Saturnine]

Lovely images Dennis, the zoom in on Gassendi and Copernicus is interesting and the resolution of the Tak is excellent on Plato. What diameters in kms and arc seconds would some of the smaller ones be I wonder and how that translates to the Dawes and Raleigh limits.

[Dennis]

Thanks for the comments Rick & Col, I appreciate them.:)

I was chasing the seeing a little as it gradually dropped off as I was increasing the magnification.

Cheers

Dennis

[Dennis]

Hi Colin

Just looking at the images, I think the Tak x1.6 and TeleVue x2 are both equally excellent in this application.

In my experience from Brisbane, I find that I can use the Tak x1.6 much more frequently than the TV x2 in terms of what the local seeing conditions can support.

The only other mechanical issue is that the TVx2 has a clean, unobstructed 2" opening at the camera end, whereas the Tak has a central boss so not all 2" accessories can slide in.

I also like the 2 locking grub screws at 90 degrees on the Tak, the TV only has a single one.

Cheers

Dennis

[Dennis]

Hi Jeff

If you want to see a Plato that blows your mind, have a look at Thierry Legault's version here:

http://www.astrophoto.fr/moon_2016august.html

This looks like it was taken from a Lunar Drone...

I think that I have resolved craterlets down to around 1.6km in my image, whereas Thierry has smashed the ball out of the resolution park with his Celestron 14" Edge and imaging skills.:)

Cheers

Dennis

[Merlin66]

Dennis,
When using the TV Powermates for imaging, I much prefer using the T thread adaptors rather than the 1.25/2" fittings. Far more rigid connection....
Just my 2c

[Dennis]

Thanks Ken, definitely the way to go for rigidity as well as physical security.:thumbsup:

Cheers

Dennis

[Dennis]

Managed to track down a CN Post on the small craterlets on Plato's floor.

https://www.cloudynights.com/topic/34841-guide-to-plato-craterlets/

I have annotated my x4 PowerMate image and think that I have candidates resolved down to maybe 1.2km, although it is hard to say with some certainty.:)

Love this desktop investigation aspect of astronomy.:)

Cheers

Dennis

[multiweb]

Looks good. You should get a baader FFC. Make the most of your optics. Sticking a televue on a TAK is like pouring water in good wine. ;)

[Dennis]

Thanks Marc - I had a look and almost fell down - over 500Euro! Might have to wait for Xmas or a birthday, when my wife isn't looking.;)

I know, I know, you only need the one and what price quality, reliability, elegant & competent design, etc..:)

Cheers

Dennis

[multiweb]

Sell all your powermates and you could finance it. :)

[Merlin66]

Marc,
Thankfully the FFC is not recommended for solar imaging.....I’ll have to stick with the TV Powermates.;)

[phomer]

Dennis,


This gives me the impression I am landing on the Moon, what memories it brings back. Very interesting.


Paul

[Dennis]

Me too Ken.:)



Thanks Paul, I appreciate your comments and much like you, I enjoyed the Apollo Missions as well the Mercury and Gemini Projects.:)

Cheers

Dennis

[multiweb]

Fair enough.

[Atmos]

The FCC is that good aye?

[Merlin66]

Talking about "good" Barlows and Powermates....I've been trialling the Baader Hyperion x2.25 barlow on solar imaging...
https://www.baader-planetarium.com/en/hyperion-zoom-2.25x-barlow-lens.html
Good T thread fitment and less Newton Rings than some other options.
Looks promising.....