34 replies to this topic

[JimP]

Hello,

 

A friend of mine has an AP 6 inch F/12 Superplanetary scope that he is considering selling to me. Does anyone have one of these scopes or has used it enough times to give an opinion you might have? And, what is the deal about the NASA glass?

 

Any thoughts are appreciated.

 

My interests: lunar, planetary and double stars. Visual only.

 

Best,

 

Jimp

 

 

[donadani]

it´s long

[John Fitzgerald]

It's  an early AP model. Takes a largish mount, G11 size.

[JimP]

Yes, 72 inches. I removed my 8” F/9 and took it to another observatory 200 miles away. The pier and AP 1200 GOTO mount was not moved.

 

JimP

[mclewis1]

History of the AP lenses from 1999 - https://groups.googl...nD2Vc_hcQ?pli=1

No details on the NASA glass, but just mentions where it was used.

 

Early comment on the origin of the glass - https://www.cloudyni...ding/?p=5876624

Edited by mclewis1, 24 May 2022 - 12:43 PM.

[Wildetelescope]

Hello,

 

A friend of mine has an AP 6 inch F/12 Superplanetary scope that he is considering selling to me. Does anyone have one of these scopes or has used it enough times to give an opinion you might have? And, what is the deal about the NASA glass?

 

Any thoughts are appreciated.

 

My interests: lunar, planetary and double stars. Visual only.

 

Best,

 

Jimp

The story goes that in the Mid 80s, Roland was able to get his hands on a batch of experimental glass that NASA was selling off, which allowed the design of what was at the time fast (f8-f12) refractors with his Triplet lens design.   The color correction was as good as there was for the time, and much better than Achromats of similar aperture and size.   This was way before the modern day LD glasses were available in size and quantity to make telescopes.   Believe it or not, AP scopes were originally the "inexpensive" alternative to the Japaneses Fluorite refractors, back in the day.  

 

I have a slightly later version of an F8 5 inch and an F9 6 inch Non ED AP scopes that are WONDERFUL visual telescopes.  Below is an image of Mars that I took with the f9 6 inch scope.   I can only imagine that the F12 scope would rock this world.   Since your friend owns the superplanetary, I would take your favorite EP's over and spend an evening with it.  If it satisfies you, then pay what he is asking for it.  Those scopes are a piece of history, and really what kicked off the Astrophotography craze that we see today. 

 

Cheers!

 

JMD

[peleuba]

Any thoughts are appreciated.

 

You'll get a lot of info from actual owners if you post this same query to the APUG, including the story on the NASA glass.  Its all in the archives and makes excellent reading, for sure.

 

These lenses were not figured with the help of an interferometer, rather, Roland used the star test and Autocollimation (DPAC).

 

They are old school telescopes with excellent performance, still very good today.

 

Perhaps your friend will let you use it prior to the purchase.

[bobhen]

HERE is a link to: A Brief History of Astro-Physics Lenses.  The detailed article mentions NASA glass among other things.

 

Back in 1989 I purchased a non-ED 152mm F9 triplet from AP. Fantastic scope!

 

Bob

Edited by bobhen, 24 May 2022 - 01:50 PM.

[fftulip]

The NASA glass as stated before was a surplus batch of glass made for NASA with abnormal dispersion characteristics that Roland got his hands on.  It enabled superior color correction but since it was a "one off" batch only a few scopes were made before it ran out.  Supposedly some of the early Superplanetary scopes used the NASA glass, later ones used off the shelf glass but still achieved excellent color correction - see the scans below from Telescope Making (Fall 1986) on the composition of the Superplanetary.  Roland also wrote an article in the October 1981 Sky & Telescope on designs using the NASA glass (I don't have that article).  Keep in mind this was before fluorite like glasses became easily available.  No, I haven't looked through a Superplanetary but I do have an Astro-Physics 5" f/9 from that era (1980's) that gives wonderful views (I believe it was made after the NASA glass ran out).

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Edited by fftulip, 24 May 2022 - 02:42 PM.

[donadani]

could please someone show some pics of that mystical scope

[Eric H]

Here's one. Courtesy of cloudy nights.

 

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[Eric H]

One more...

 

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[donadani]

he, he... -  definitely.... long!

[weis14]

That is a big beast!  I've never seen one in the wild, but it would be fun to compare the images between a vintage AP 6" and a modern 6" APO.  I have a CFF160 we can use for the modern side of the comparison. 

[stevenwav]

The very last batch were "Starfires" and I believe they were air spaced - I had one. I think there were three versions of these in total- not sure. Really a wonderful scope, I only sold it because I had an AP 178 f/9 at the same time, so I opted fro the larger aperture. While the 6 f/12 is very long, it is relatively very lightweight due to the aluminum tube, so the only mounting issue is the length ("moment arm" I guess) which caused some wobble even with my G11 on an HD Losmandy tripod. Your AP mount will be be better so no concern there obviously, but I would get the longest plate I could - 16" and as long as you had a really solid tripod or pier, you would be ok.

 

I used to have fun viewing with my Clave eyepieces up to 75mm's. Gave me a real "observatory" feeling swinging that long scope around and using old school eyepieces. The moon was excellent, the planets were very good under my lousy New England skies, but the 178's aperture was more enticing to drag out and use when I had them both at the same time.

 

I also had a 130 f/12 - earlier version, not as good color-correction wise as my previous 6" scope. Since you are asking about the NASA glass, I am guessing the version you can get is the first batch. Worth getting if the price is right and if you want to "rock it old school". Would I get one again especially if I already own say an AP 130GT, or 155 triplet? No. I would though, if I could get another sample from the last run. So, my recommendation is to get it if you want to have fun, but I would not really want to replace my other scopes to own it. 

 

Just a final thought - these are older scopes, have the older focusers etc, so my point is that it is not a "slick" scope. Having said that, with an f/12 focal length, you don't exactly need a featertouch focuser -lol. So you do get all of the added benefits and advantages a long focal length brings to the party, the details of which I will not get into here, there are plenty of threads on that already. 

Edited by stevenwav, 24 May 2022 - 03:19 PM.

[vahe]

In 6" class APO's the AP 155 EDT F9 from performance standpoint is the true Superplanetary AP refractor. The original 6" F12 Superplanetary is also fine but if you want the very best visual refractor for lunar/planetary/double stars from Astro-Physics look for the 155 EDT F9.

.

Thomas Back had this to say about these two scopes in his "History of Astro-Physics Lenses":

.

"Then the new era began. It was AstroFest 1990, and Roland brought his ultimate line of ED EDT triplets. I had my 6"f/12 setup next to the new 6.1" f/9 EDT, and at first glance cast on Saturn, I knew it was all over. This scope was a knockout, and in color correction and contrast, clearly beat my 6" f/12 Super Planetary. This was a prototype, was airspaced and not even coated."

.

Vahe

[Alan French]

 Roland also wrote an article in the October 1981 Sky & Telescope on designs using the NASA glass (I don't have that article). 

If anyone looks at this article, keep in mind there was a correction in the April, 1982, issue of "Sky & Telescope." (The first edition of Rutten and van Venrooij's "Telescope Optics" evaluated a design derived from the original "Sky & Telescope" article, without the correction.) 

 

Clear skies, Alan

[Wildetelescope]

That is a big beast!  I've never seen one in the wild, but it would be fun to compare the images between a vintage AP 6" and a modern 6" APO.  I have a CFF160 we can use for the modern side of the comparison. 

I was part of a discussion about these older scopes on APUG a while back.  In it Roland basically said that if you are shooting Narrow band, the older scopes performance should be comparable to the newer versions.     A second thing Roland mentioned was that these were designed such that the color blur was ~5 microns, and that the CCD pixel size from that time was ~7 microns or so.  

 

I use mine with OSC cameras(images in my galleries) and you will definitely see some lateral color on bright stars, especially if they are oversaturated.  But more often than not, the effect is easily dealt with in processing.   The image of Mars (captured with an F9, not the F12) is processed to the best of my ability of course, but I have never seen either visually or photographically any evidence of gross CA fringing on Jupiter, Saturn or Mars.  That said, I suspect that I did loose some of finer detail on Mars due to blurring(compared to what I might get with a modern triplet), since I was using a camera(290 chip) with small pixels.   Laws of physics still apply:-).  All and All, not bad for a 30+ year old scope.   Visually, the 6 inch gave me the first view of dust lanes in Andromeda from my Bortle 6 back yard of any of my scopes.  Contrast in these scopes is just phenomenal.  

 

Cheers!

 

JMD

[weis14]

I was part of a discussion about these older scopes on APUG a while back.  In it Roland basically said that if you are shooting Narrow band, the older scopes performance should be comparable to the newer versions.     A second thing Roland mentioned was that these were designed such that the color blur was ~5 microns, and that the CCD pixel size from that time was ~7 microns or so.  

 

I use mine with OSC cameras(images in my galleries) and you will definitely see some lateral color on bright stars, especially if they are oversaturated.  But more often than not, the effect is easily dealt with in processing.   The image of Mars (captured with an F9, not the F12) is processed to the best of my ability of course, but I have never seen either visually or photographically any evidence of gross CA fringing on Jupiter, Saturn or Mars.  That said, I suspect that I did loose some of finer detail on Mars due to blurring(compared to what I might get with a modern triplet), since I was using a camera(290 chip) with small pixels.   Laws of physics still apply:-).  All and All, not bad for a 30+ year old scope.   Visually, the 6 inch gave me the first view of dust lanes in Andromeda from my Bortle 6 back yard of any of my scopes.  Contrast in these scopes is just phenomenal.  

 

Cheers!

 

JMD

I should have said "views" instead of "images".  I'm sure the AP comparison is interesting, and the Mars shot is fantastic, but I'm really here for the visual views.  

[George N]

I've been using - off & on - an AP 6" F/12 since it was obtained for Kopernik Observatory & Science Center - Vestal, NY by Don Yeier - from an estate sale, when the telescope was about a year old. It spent many years on different mounts - taken to Stellafane at least 3 times. Today it is in a dome on a Losmandy G-11 mount.

 

The original focuser (believe it was a Unitron part supplied to AP by Don Yeier at the time) was pretty primitive - 'pot metal' casting, plastic strip supporting the rack - it did not survive use by "the educators" observatory staff for very long - and the scope now has a Moonlite 3.5" focuser on it. It makes an excellent up-grade.

 

Inside a dome - or with little to no wind - a G-11 is 'enough' to hold the AP6 - for both visual and imaging - but expect some 'giggle' when focusing - nothing awful - but certainly a lot more than I'm use to with my 20" Dob. The OP is talking 'visual only' - for imaging, I'd put an electric focus motor or it.

 

Yes it is *long* -- we mostly use 2 people to get it on the mount - or shift it in the tube rings for balance with heavy things like DSLR/Barlow or bino-viewer. It was certainly 'interesting' taking it to Stellafane - but lots of folks liked the views.

 

At some point - early 2000's???? - a large ring of cork fell out of the lens and down the tube. RC said "don't use it - send the lens in quickly" - which we did. In relatively quick time (few weeks) it was returned, cleaned, lens elements re-installed in the cell, cork or whatever replaced.

 

I've read that TBack quote many times over the years and - I'll take it as his opinion - which I find difficult to confirm. For about 10 years a friend owned the 'other' AP (he moved to Hawaii - with the scope!!) - and I viewed thru them side-by-side on many a night, and didn't see any difference. But what do I know? I also looked at Mars at opposition thru a friend's Obsession 20 F/5 Dob on the same night with both refractors (plus a C-14 and C-11) and -- a week later I bought a used Obsession 20 off of A'mart!

 

Of the many objects and views I've had thru that 6" F/12 -- the most memorable was -- the Comet Shoemaker-Levy 9 hits on Jupiter - first night they were visible. We were reading reports from Europe of big black spots on the planet - but I was not totally 'in to it' - until I got the observatory's 20" F/8 RC Cass on Jupiter in still very bright twilight. A yell from outside at the same instant meant that the guys outside with the 6-inch F/12 saw 'them' too. I walked out and the 'Superplanetary' was certainly living up to its name that night! Another memorable observation: the last transit of Mercury - I have images somewhere.

 

Fast forward to May 2022 - it was just used for a 'live' webcast of the recent lunar eclipse - and some claim that over 250,000 viewed at least some of it.

 

<< I'm at the wrong PC to find pictures - maybe later >>

 

Bottom line: If the price was right (compared to modern scopes and with the possible need for a new focuser) and I could deal with a "telephone pole of a telescope" - I would buy one.

Edited by George N, 24 May 2022 - 05:11 PM.

[JimP]

Vahe,
Please send email address and price where I can purchase one(155 F/9) Lol! I know my friend Arpad owns one and I don’t think he would sell it for anything.

JimP

[JimP]

The owner is shortening the OTA using advice from the folks at AP. Has a feathertouch focuser.
In a way, it would be a road down memory lane as my first and only other AP 6” F/12 was the first AP scope that I owned. Roland had made a prototype Folded OTA. It was about the size of a C8 but much heavier. I remember viewing Jupiter through it and the view was superb! No, I no longer have it as a gave it away to an acquaintance and ordered an AP 155F/7. I later saw the lens for sale on Astro Mark and I just ignored it.

JimP

Edited by JimP, 25 May 2022 - 08:25 AM.

[JimP]

I also have a fair number of Clave eye pieces!

[vahe]

Vahe,
Please send email address and price where I can purchase one(155 F/9) Lol! I know my friend Arpad owns one and I don’t think he would sell it for anything.

JimP

Those are very hard to find.

.
I have one, Roland worked on mine, it is my first and last refractor, I am keeping it till the end.

.
One was advertised on CN, ad Number 220647, sold for $14,900.00.

.
According to Roland these early ED refractors were figured in Yellow light, 593nm, that is before AP started using interferometry in mid nineties and started figuring lenses in green light 543 nm. They also benefitted from the use of a mating element that is no longer available, this mating element allowed full cancellation of spherical aberration resulting in unusually clean planetary images, pure white lunar images.

.

Vahe

[JimP]

Wow! While I am not surprised I am certainly very impressed!

JimP