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Me and My D&G

Started by 1953, 08/29/2009 06:36AM
Posted 08/29/2009 06:36AM Opening Post
Barry makes good lenses. 11" F12, old Cave Observatory mount modified with a 10" Mathis drive system and Cave pier. Built the tube assembly my self....all 110 pounds of it.

This scope is magnificant, giving me the best views of Jupiter, M13, M27, M92...I've EVER had. Plays nice with my Chromacor too.

Jeff

Attached Image:

1953's attachment for post 48071

"Don't sweat the petty things and don't pet the sweaty things" 8O
Posted 08/29/2009 06:36AM #1
Another view

Attached Image:

1953's attachment for post 132319

"Don't sweat the petty things and don't pet the sweaty things" 8O
Posted 08/29/2009 06:41AM #2
Jeff Blazey said:

Barry makes good lenses. 11" F12, old Cave Observatory mount modified with a 10" Mathis drive system and Cave pier. Built the tube assembly my self....all 110 pounds of it.

This scope is magnificant, giving me the best views of Jupiter, M13, M27, M92...I've EVER had. Plays nice with my Chromacor too.

Jeff

Jesus Christ Bananas! That is a big and impressive scope! Enjoy!

Uncle Rod

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Posted 08/29/2009 07:08AM #3
Now THAT is what a telescope should look like! Congratulations on such a fine instrument!
Posted 08/29/2009 07:54PM #4
Posted 08/30/2009 06:48AM #5
Words!! Words!! Come on, there must be some words to describe that setup, but I'm so dumbfounded impressed, I can't think of any!

Thanks for the wonderful pictures!
Paul Maxson

Paul Maxson
Moderator - CCD Imaging and Processing/Solar System
Celestron C14, Mewlon 250, Orion EON120, ASI120MM, Flea3.
http://www.sunspot51.com
Posted 08/31/2009 05:20PM #6
Well, the lens is supurb. I can detect no zones or residual spherical in geen light and the figure seems exceedingly smooth with no edge issues at all. Once thermally stablized and seeing permitting, I get a very nice, tiny, intense airy disk with a faint first ring. To be honest, I've never seen a good steady airy disk from ANY aperture over 8-9" but the seeing this summer has been, at times, exceptional here in southwest Ohio.

False color. Well yes, after all it is a big, relatively fast achromat, but I gotta tell yah it's not NEARLY as subjectively bad as I was preparing myself to deal with and quite easily ignored especially at lower powers. And you know what, I and several others who've look at Vega, for example, have actually enjoyed the view better without the help of the Chromacor. There is a certain beauty to the intense deep blue/purple that's a bit beautifully arresting. It's also easy to ignore the CA as the lens is so stunningly sharp! That's what grabs my attention front and center.

And who says a large achromat is not really a deep sky object scope. It excells at deep sky with some of the best views of M13, M92, M27 and so forth I've EVER had. M92 in particular was a pile of diamond dust on black velvet.

As the lens cools, I also chronically start the observing session with an 8.5" aperture stop, which yields an F16 focal ratio. At this point it's a toss up as to using the Chromacor at all. Again I'm a bit taken aback by how LITTLE false color there is. With the 6" stop it's just not an issue at all at any magnification I care to use. I told Barry I'd be using various stops depending on seeing. Using stops has been a mixed bag on previous achromats as many tend to have zones in the middle. Barry said, "Don't worry about that. There'll be no center zones". Indeed. He was right. With the exception of the reduced CA the 8.5" & 6.0" stopped lens looks just as well corrected in green as the full aperture.

And a word about the Chromacor. I love it. I do need the proper spacers and yeah, I do get lateral color at full aperture but when I find the on axis sweet spot (which is about a 3-4 Jupiter diameter), there is only a smidge of CA left. It's very similar to my 5" F8 1989 vintage AP on axis. One night during exceptional seeing when using it at full aperture on Jupiter the amount of unforced, easy detail was spectacular. The polar regions in particular were alive with subtle detailing. I've never seen such a range of detail before on Jupiter. On the moon, Plato was again spectacular. Cratelets? You bet! And all over the place and the floor of the crater is not flat. And don't get me going about using the Denk II.

I'm happy....VERY happy.

Jeff




"Don't sweat the petty things and don't pet the sweaty things" 8O
Posted 10/01/2009 08:08PM | Edited 10/01/2009 08:08PM #7
Good lord...now that's a *scope* if I ever saw one!

It must have been fun building the tube assembly! wink
Posted 10/03/2009 07:05AM #8
8) That's an awesome setup!!!, Jeff!! You must be very proud!! Clear Skies!!