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Modern Version of a Classic Long Refractor?

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#126 Jon Isaacs

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Posted 17 September 2013 - 10:11 PM

Took the4" F15 Jaegers to a public event on Saturday. The club president was really impressed with the Epsilon Lyra. Perfectly resolved with just a faint hint of the first ring.



Epsilon Lyrae is a pretty easy split for a 4 inch, I get a split in my 100mm F/6 achromat with a 9mm, that's about 67x. It's an easy split in a decent 80mm... it gets a sketchy in an ST-80..

Nearby, Delta Cygni is a better test, it's a little wider but the seconday is almost 4 magnitudes fainter than the primary. I have yet to split it in my 100mm F/6 achro, I get good splits in the 80mm apo and the 100mm apo. I would expect the 4 inch F/15 to do a very nice job.

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#127 photiost

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Posted 17 September 2013 - 10:21 PM

Interesting read on the 4in f/11 Kunming..

I have the Celestron (Vixen) SPC102 @ f/9.8 and I am very pleased with this scope.

Just wondering, does anyone here know how the SPC102 would stand up against the Kunming ?

:question:.

#128 bremms

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Posted 18 September 2013 - 09:21 AM

Epsilon is a very easy split.. You could dance between the components. It looked better than the the SCT's that were there. Four perfect airy discs. Epsilon L is split in a good 60mm. My Zeiss traveller will show it split very easily.
I was showing to the general public. That's why we were looking at E Lrya. Even first time telescope users were impressed.
Delta Cygni and epsilon Bootis are pretty easy in this scope if the seeing is good.

#129 Jon Isaacs

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Posted 18 September 2013 - 10:36 AM

Epsilon is a very easy split.. You could dance between the components. It looked better than the the SCT's that were there. Four perfect airy discs.



Indeed... it is an easy split. Viewing the Airy disks and diffraction rings is about the seeing and the size of the exit pupil. An 8 inch scope requires 2x the magnification of a 4 inch to see the Airy disks and therefore it is more sensitive to seeing. At larger exit pupils, the eye does not resolve the disks, it's not the scope...

Jon

#130 semiosteve

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Posted 18 September 2013 - 11:10 AM

I thought it was a pretty straightforward split with my recently acquired 60's Tasco 10te (76mm) -it did fake me out as it looked so tiny and compact in low power compared to my usual view in my AP180 that I wasn't sure I was looking at it at first..I was out of practice with scope from that time period.

Very pleased with Lunar views so far.

I have all 3 scopes in my rolloff (Obsession, AP and Tasco). Visitors are still drawn to the Tasco ...something about these old long FL refractors that just seems to communicate the essence of the word 'telescope'.

#131 terraclarke

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Posted 18 September 2013 - 11:31 AM

Hi Mike,
I was playing as well. Love the hat. Looks just like the one Kyle Broflovski wears on Southpark, albeit its not green. Neat scope restoration project BTW. Love to see BIGGER pictures. ;)

#132 photiost

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Posted 18 September 2013 - 11:44 AM


Epsilon Lyrae is a pretty easy split for a 4 inch, I get a split in my 100mm F/6 achromat with a 9mm, that's about 67x. It's an easy split in a decent 80mm... it gets a sketchy in an ST-80..

Nearby, Delta Cygni is a better test, it's a little wider but the seconday is almost 4 magnitudes fainter than the primary. I have yet to split it in my 100mm F/6 achro, I get good splits in the 80mm apo and the 100mm apo. I would expect the 4 inch F/15 to do a very nice job.

Jon


I have split E-Lyra (easily) with my Celestron (Vixen) 80mm f11.4 refractor using a 20mm eyepieces @ 46x

.

#133 Jon Isaacs

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Posted 18 September 2013 - 12:34 PM



Epsilon Lyrae is a pretty easy split for a 4 inch, I get a split in my 100mm F/6 achromat with a 9mm, that's about 67x. It's an easy split in a decent 80mm... it gets a sketchy in an ST-80..

Nearby, Delta Cygni is a better test, it's a little wider but the seconday is almost 4 magnitudes fainter than the primary. I have yet to split it in my 100mm F/6 achro, I get good splits in the 80mm apo and the 100mm apo. I would expect the 4 inch F/15 to do a very nice job.

Jon


I have split E-Lyra (easily) with my Celestron (Vixen) 80mm f11.4 refractor using a 20mm eyepieces @ 46x

.


I think that is a test of your vision more than anything... I have convinced myself that I see the splits at powers as low as 40x but I wouldn't call it easy... I have seen the split so many times, at such low magnifications I always wonder if it is simply "averted imagination".

Jon

#134 photiost

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Posted 18 September 2013 - 01:12 PM


I think that is a test of your vision more than anything...

Jon



You are probably right.

Now that you mentioned it, one of our younger members says he can see the split with his 80mm Apo @ 37x ..

Can't say I have tried the split at 40x but at 46x I can make out both doubles quite nicely.

I remember we did a test one night and some of our senior club members were not able to see it (in my 80mm scope) even at 61x with a 15mm eyepiece ... however using a 10mm at 91x everyone was able to see the split.
.

#135 semiosteve

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Posted 18 September 2013 - 04:32 PM

"averted imagination"

That is what I use when I am at work thinking it will be clear later...

LOL

#136 Mike W

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Posted 18 September 2013 - 05:12 PM

Hi Mike,
I was playing as well. Love the hat. Looks just like the one Kyle Broflovski wears on Southpark, albeit its not green. Neat scope restoration project BTW. Love to see BIGGER pictures. ;)


Hi Terra,
I've still got the hat! I'll work on some bigger photos tonight.

#137 Mike W

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Posted 18 September 2013 - 06:31 PM

Post deleted by Mike W

#138 Mike W

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Posted 18 September 2013 - 06:32 PM

Here the tube is still together (joins at grey housing) but pieces are coming off one by one.

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#139 Mike W

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Posted 18 September 2013 - 06:35 PM

I'm measuring the main objective to get it back in someplace close to collimated. (feeler gauge)

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#140 Mike W

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Posted 18 September 2013 - 06:38 PM

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#141 Mike W

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Posted 18 September 2013 - 06:44 PM

Here's the manual dec control I mentioned earlier. There was no money in the budget to repaint but when I was done the rust was gone and everything that wasn't painted black shined up like new.

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#142 Mike W

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Posted 18 September 2013 - 06:48 PM

Chasing out the threads with a tap to re-install the DEW CAP.

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#143 clintwhitman

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Posted 19 September 2013 - 04:23 AM

Awesome Mike I had a tangle with the prototype 6" GOTO a few years back. My Friend Steve Miller purchased it from a friend they both had a hand in the complete restoration. It is a beauty. He took it to 8500 feet MT. Pinos 3 years in a row where we assembled it up for CSPAMP. It was something to see. Good seeing and hope all goes well with your work!!
(aveman
Here somthing you will never see again Steves 1956 GOTO 6" F15 Prototype Observatory refractor and The PEARL, the only 9" F10.6 Astro Physics refractor Roland ever made set up at 8500 feet, Mount Pinos Parking lot CSPAMP 2010

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#144 clintwhitman

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Posted 19 September 2013 - 05:17 AM

Modern Version of a Classic Long Refractor?
Well getting to the topic. I don't really own any modern ones. There are to many real classics out there and I have a quiver full. You know I love refractors and have a soft spot for the long FL old-timers. The closest I can come is the Unipons. I am in progress of building this telescope around a truly wonderful 1962 Jaegers 6" F15 that exhibits a perfect star pattern and very little chromatic aberration.The Objective was purchased by Mount Wilson Observatory in 1962 where it sat unused for 30 years, then Pons traded it for some work he did at the Observatory. This coupled with the brand new (5 years old, Already?) John Pons OTA it is a one of a kind telescope. I have had this scope out only a few time until I recently decided to built a dedicated mount for the telescope so it is getting more light than ever. At this point I have found that it loves BinoViewers. The pitch black backgrounds (7 Baffles) and really nice 6" resolution makes it a great telescope to use. The long focal length telescopes give a depth of field that is not found the shorter APOs, APOS are designed to have a flat field for astrophotography right? So these long fellows are designed to fill your eyes with the wonder of dark matter, dust lanes and stars with colorful little bumps on them. I am sure there are a slue of new long focal length telescopes out there and I have known Rich "The FL GodFather" for many years, both scrambling for the same f15 Unitrons LOL,I am hoping to get a peek thru one of the new Tele Vue lenses.. I Wonder???

I will say one other thing Viewing Saturn last month at Pinos with the Unipons, Great View at 450 power. Dans 6" AP EDSF at F9 did not have any competition from any scope I looked thru Magnificent! :bow:
The Unipons first time on its new mount My Wife 5'8" Give me some real prospective reference.

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#145 terraclarke

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Posted 19 September 2013 - 08:02 AM

Hi Clint,
Every time I see pictures of your 6 and 9 inch refractors, I say to myself, "How cool!". I gotta get out there to Space camp one of these summers to see them in person. That would be a real treat. Thanks for sharing. :flower:

#146 bremms

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Posted 19 September 2013 - 09:26 AM

Those are nice scopes Clint. I'll be working on a 7" AP that is part of the collection at the Sate Museum. It will be used for public observing. Somehow, I got roped into getting it working. I'll take some pics as I'll be cleaning the lens with some staff next week. There may be some damage to the lens, deposits and such. They talked to Roland and he said to clean the lens and if it looks bad we will take things from there.

#147 Mike W

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Posted 19 September 2013 - 05:41 PM

Awesome Mike I had a tangle with the prototype 6" GOTO a few years back. My Friend Steve Miller purchased it from a friend they both had a hand in the complete restoration. It is a beauty. He took it to 8500 feet MT. Pinos 3 years in a row where we assembled it up for CSPAMP. It was something to see. Good seeing and hope all goes well with your work!!
(aveman
Here somthing you will never see again Steves 1956 GOTO 6" F15 Prototype Observatory refractor and The PEARL, the only 9" F10.6 Astro Physics refractor Roland ever made set up at 8500 feet, Mount Pinos Parking lot CSPAMP 2010

Beautiful restoration, I can't say enough! I've gotta tell you seeing that scope together and not bolted down scares me a little! It would have been nice to repaint some of the scope but budget, and time weren't in the cards. The teacher was pushing to get the scope usable. What's a little patina matter anyway!



#148 beanerds

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Posted 19 September 2013 - 10:32 PM

I had a Takahashi FS60C and a Zeiss Telementor 2 at the same time , a f5.9 Fluorite doublet and a F13.3 doublet achromat .
I sold the Tak and kept the Zeiss because in my eyes the Zeiss gave nicer ( natural ? ) views of ever object I tested them both on .
The Zeiss .
Brian.

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#149 mikey cee

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Posted 19 September 2013 - 11:38 PM

Hi Mike,
I was playing as well. Love the hat. Looks just like the one Kyle Broflovski wears on Southpark, albeit its not green. Neat scope restoration project BTW. Love to see BIGGER pictures. ;)


Hi Terra,
I've still got the hat! I'll work on some bigger photos tonight. I'm supposed to do a talk for the local club on that restoration but I've been dragging my feet. Looking at the photos is giving me renewed energy. My favorite is the 10-3/4" Alvin Clark, I can use anytime I want if I feel like driving to CT! It's in Artists in Optics as the Butler telescope. Actually anyone can look through it when my friend Dave has open house.
Anyway I'm rambli'n and gotta eat.
Mike

As Ziggy would say if he saw this! :shocked: Alvin is the chipmunk. :smirk: Mike

#150 terraclarke

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Posted 20 September 2013 - 08:35 AM

Here' (one of) mine, a modern classic- the AstroTelescopes 102mm F11 on a CG-4 mount with rear tube balance weight system.

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