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3 aperture Saturn reflections (and refractions)

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#1 azure1961p

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Posted 13 June 2013 - 12:04 AM

Seeing was typically excited tonight with some nicer settled air coming in around midnight . I've had three different scopes now on Saturn this apparition and I thought Id make some comparisons...

The 70mm achro does a very impeccable job of providing a high def Saturn but at the cost of simpler details. The hexagon is total shutout, though the equatorial Belt and accompanying zone stand out nice, if somewhat soft as its res is just 1.65 Dawes. The bottom line is sharpness but plainness. Cassinis shows nicely but its shorter and blunter appearing. I've NEVER seen the crepe ring, though the a-b albedo difference is seen regularly.

The C6 provides a yellower Saturn to Rangers grey cream. Everything g here is better than the 70mm as you'd expect. Cassinis follows out from the ansae , much farther infact, and the division at the ansae reveals real angular seperation as opposed to Ranger grey linear contrast streak. The physicality of he gap makes the 6" a more rewarding view than the flatter Ranger - which though does unbelievably well for a mere 70mm!!!

The 8" right off the bat has a darker Cassini division while through the ,
C6 its a paler shorter version. Both do a nice job but the c6 just doesn't have the 8"s clarity . The upper temperate zone that subtly visible in 6/10 seeing through the 8" isn't even beginning to tickle at the idea. The Hexagon is finally showing here as a spot while the same seeing yields a perfectly smooth and blank region in the 6". The 6" gives color and some more retain definition in the simpler details while the 8" begins to reveal the finer structures and contrasts. The C ring is routine in the 8" while the 6" needs good seeing.

My finds this year.


Pete

#2 leviathan

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Posted 13 June 2013 - 12:33 AM

The C ring is routine in the 8" while the 6" needs good seeing.

Agree.

#3 george golitzin

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Posted 13 June 2013 - 03:46 PM

I recall the C ring was pretty routine in my old MK-67 (6-inch russian mak,if you recall), but Saturn's rings were more wide open then...

Interesting comparisons Pete, thanks for posting.

I'm reminded, by the way, how much patience is called for in planetary viewing--two nights ago I had the 12.5-inch out, and the seeing was garbage for a long while. I viewed some DSOs and came back to the planet on a what-the-heck-let's-take-one-more-look kind of whim, and bang, the air was steady. For about 30 seconds! But wow, it's just so beautiful when the air is steady--the bands were etched on the planet, the various shadows were obvious, crepe ring, encke minima, etc very clear. And then the image dissolved once more into mush, and stayed that way. So I packed up.

-geo

#4 azure1961p

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Posted 13 June 2013 - 05:42 PM

Hi George,

Generally Ive found seeing later in the night is more stable than say : 10:00pm in August. After midnight it seems like some truly tranquil seeing conditions can really take hold. Same for 3:00am.

Ill say it WAS nice to get that sct out again!!!

Your accounts were good reading.

Pete

#5 Rick Woods

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Posted 13 June 2013 - 06:21 PM

I got a great view of Saturn in my 8" f/6 last night. I started with a 4.8mm Nagler T1 (254x), a very sharp eyepiece; then switched to an 8mm Brandon + 2.4x Dakin barlow (366x), which was an excellent combo. Saturn was almost 3D, it was so sharp and detailed. I wish I had opened the observatory and used the SCT, but the night was so hot, dusty, and hazy, I thought the seeing would suck.

#6 azure1961p

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Posted 13 June 2013 - 11:44 PM

Rick - I am looking forward to a 3D Saturn - particularly with the binoviewer. As it is my *low power* with my paired Orthos for the Maxbrights gives me something like 350x which is just too too much for typical seeing here in ct. Not saying its bad on great nights but merely that it'd be a lot more versatile a contraption if I could get 200x out of it with the same scope. I'm looking at 32mm plossls or 28mm RKEs.

I'm glad you had a nice crisp image Rick!!

Petr

#7 REC

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Posted 14 June 2013 - 08:02 AM

Nice report, I'll have to try that with my 80ED, 125Mak and C8 to compare. What power EP's where you using in all three?

Bob

#8 Meep_Esq

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Posted 15 June 2013 - 08:30 PM

Hi Pete. Interesting post. I've been watching Saturn off and on this opposition with my 100mm refractor. Several times I've wondered if the crepe ring was visible as a fuzzy edge to the B ring where it passes across the planet. It's seemed more obvious than any surface belt. If that's the case then I wonder if your 70mm would catch it?

kind regards.

#9 azure1961p

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Posted 15 June 2013 - 09:05 PM

I ve seen it with 70mm where it crosses the planet as u have. Nothing is particularly prominent with that scope in terms if planetary features, savf for the rings , but that did show repeatedly . I kno Stephen James Omeara caught the C ring at the ansae with a 6omm refractor - no doubt a Unitron - but I haven't had the pleasure of that (yet?) with my refractor.
I have no doubt your 100mm would show it nicely in good seeing all the way around.

Pete






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