55 replies to this topic

[Scott in NC]

Here’s a rare gem that I picked up from a semi-local seller a couple of days ago, a vintage AP Star12 ED from the 1990-1991 era. It’s a 120mm f/8.5 air-spaced doublet with an ED element consisting of either FPL-51 or -52 glass, depending upon which source you read, and I don’t believe that AP ever disclosed this for sure.

 

A friend of mine has had one of these for about 15 years, and I got the chance to do some H-alpha solar observing with his at a star party last fall. So when I saw another one up for sale I was intrigued, especially since the seller was willing to meet me a little over an hour away from where I live.

 

The scope has a few paint chips here and there and a couple of very shallow tube indentations, but nothing too objectionable. The most important parts, the optics and the focuser, are in very nice shape for a 35-year-old scope.

Edited by Scott in NC, 16 March 2025 - 04:33 PM.

[Scott in NC]

[Scott in NC]

[Scott in NC]

[Scott in NC]

[Look at the sky 101]

You'll love this AP, it's very surprising.
Do you know if it's separated by air or oil?

[Scott in NC]

Somehow it escaped the “new scope” curse, and I was able to observe with it the same night that I bought it. Seeing was below average that night and there was a full Moon, but none of that really bothered me, as I was just happy that the weather was finally warm enough to observe without a jacket. I won’t bore you with my whole observing list, but do want to mention that I got a fantastic view of Jupiter. The only Jovian views that I’ve seen better have been on nights with above average seeing, using larger triplets or a premium Newt.  The belts looked like they were etched onto the planetary disc, and I was quite impressed.

 

The focuser is the traditional AP quality, and even though I prefer dual-speed focusers, for an f/8.5 scope, single-speed was really just fine for me. The only thing that I didn’t like about the focuser was that it would tend to slip when the scope was pointed toward the zenith while using a 2” diagonal and Pentax XW eyepiece, unless I fully tightened the tension knob. I don’t think there’s actually anything wrong with the focuser though, as the movements were very smooth and precise, and the rack appeared to be in perfect shape. I’m reasonably sure that I can tweak it to perfection, but I was too absorbed in observing to worry about that, and that project can await another day.

 

Today I took the scope out to for some white light solar observing with a Herschel wedge. Never mind the fact that we’re experiencing 30+ mph wind gusts and seeing was poor, I was still treated to some very nice sunspot views with a 22mm Vixen LVW and 27mm Panoptic.

[Scott in NC]

You'll love this AP, it's very surprising.
Do you know if it's separated by air or oil?

I believe I’ve read that AP might have made a few of these with oil-coupled optics, but I’m pretty sure that this is air-spaced, as there are three spacers visible. I updated my first post in this thread to reflect that.

[Scott in NC]

Yesterday I also got the opportunity to DPAC test this scope, and I brought it over to scoale’s house so we could test it along with his new TEC 160FL (details here: https://www.cloudyni...147/?p=14025913). You’ll notice on the white light images that there’s a little more chromatism than you’ll see on the newer AP FPL-53 triplets, but I think this likely still meets the definition of apochromatic. The figure is very nice, with quite low levels of spherical aberration in green and red. Ignore the oblong-shaped reflections in the center of the images. I had a window behind me, and really didn’t feel like moving the whole setup to completely eliminate that.

 

 

[CHASLX200]

4K SCOPE USED.  Never see any pop up.

[Scott in NC]

Overall I’m pretty pleased with this scope, and think that with a little TLC it’s going to be even better.

[Scott in NC]

4K SCOPE USED.  Never see any pop up.

Chas, don’t worry—I didn’t pay anywhere even close to that. And as much as I like it, had it been listed for $4000 then I would have passed. If I had wanted to pay $4000 for a 120mm scope, I would have bought a more modern FPL-53 triplet like a TSA-120.

[CHASLX200]

Chas, don’t worry—I didn’t pay anywhere even close to that. And as much as I like it, had it been listed for $4000 then I would have passed. If I had wanted to pay $4000 for a 120mm scope, I would have bought a more modern FPL-53 triplet like a TSA-120.

Well one near me went for 4k last year. Maybe the price dropped. But it did include a nice set of rings, case and 2" Everbright diagonal.

[Scott in NC]

You'll love this AP, it's very surprising.
Do you know if it's separated by air or oil?

I see you have one too. How long have you had it, and do you know if yours is air-spaced like mine?

[Scott in NC]

Well one near me went for 4k last year. Maybe the price dropped. But it did include a nice set of rings, case and 2" Everbright diagonal.

I think that since these are pretty rare, there’s not really an established market value as there is with many more modern scopes. The price is simply whatever a willing buyer and seller are able to agree upon. And while I wouldn’t have paid $4000 for this (at least not in 2025; in 2035 or 2045, who knows?), I’m quite pleased with it for the money that I spent. And that’s all that I’m going to say on the subject.

[CHASLX200]

I think that since these are pretty rare, there’s not really an established market value as there is with many more modern scopes. The price is simply whatever a willing buyer and seller are able to agree upon. And while I wouldn’t have paid $4000 for this (at least not in 2025; in 2035 or 2045, who knows?), I’m quite pleased with it for the money that I spent. And that’s all that I’m going to say on the subject.

Be nice to slap it next to a FS102 and see what wins.

[Don W]

Nice find!
 

I had one in the mid-90s.

 

DonW

[Wildetelescope]

Nice scope!  

 

JMD

[The Ardent]

NEAF Solar star party 2011 

Attached Thumbnails

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[Scott in NC]

NEAF Solar star party 2011 

Very nice! Looking through yours last fall was what inspired me to get this when I saw the ad.

[Look at the sky 101]

I see you have one too. How long have you had it, and do you know if yours is air-spaced like mine?

Mine is oil-separated. When I spoke to the people at AP, they explained that only 10 were built with oil separation.
There are only a hundred copies of this instrument.
They also confirmed that it was an FPL-52 lens.
Which at the time was environmentally friendly.

 

 

I have had this instrument for ages, 1990 to be precise.

Edited by Look at the sky 101, 16 March 2025 - 05:50 PM.

[Wildetelescope]

Very nice! Looking through yours last fall was what inspired me to get this when I saw the ad.

I think this is the only doublet that AP ever made, correct?  I was always curious to look through one:-)

 

JMD

[Scott in NC]

I think this is the only doublet that AP ever made, correct?  I was always curious to look through one:-)

 

JMD

I believe they also made a small number of 102, 130, and 155mm doublets for a short time in the early 1990s or sometime thereabouts.

 

Edit: AP apparently just made 120, 130, and 155mm doublets, not 102mm as stated above. That one was a triplet.

Edited by Scott in NC, 16 March 2025 - 09:07 PM.

[scoale]

Yesterday I also got the opportunity to DPAC test this scope, and I brought it over to scoale’s house so we could test it along with his new TEC 160FL (details here: https://www.cloudyni...147/?p=14025913). You’ll notice on the white light images that there’s a little more chromatism than you’ll see on the newer AP FPL-53 triplets, but I think this likely still meets the definition of apochromatic. The figure is very nice, with quite low levels of spherical aberration in green and red. Ignore the oblong-shaped reflections in the center of the images. I had a window behind me, and really didn’t feel like moving the whole setup to completely eliminate that.

 

AP Star12 ED copy.png

I was quite impressed with this 35-year-old scope.  It is VERY light, has a very nice figure, and I was super impressed with the focuser.  Also really like the longer focal length.  Remarkable scope.

[Scott in NC]

I believe they also made a small number of 102, 130, and 155mm doublets for a short time in the early 1990s or sometime thereabouts.

 

Edit: AP apparently just made 120, 130, and 155mm doublets, not 102mm as stated above. That one was a triplet.

 

This post in this thread from 2010 discusses AP’s 130 and 155mm doublets.

 

https://www.cloudyni...ar12/?p=3636888