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A Brief History of Astro-Physics Lenses

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#1 imtl

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Posted 05 December 2021 - 07:03 AM

Hi all,

 

I found this old article by TB from 2003 reviewing AP lenses. I thought it might interest some of you here. If it was already posted in the past then apologies.

 

https://www.csun.edu...n/tmb/tmb1.html

 

More stuff from TB are here.


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#2 lee14

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Posted 05 December 2021 - 07:36 AM

There was an article in S&T during the 90's comparing the excellence of the AP's with the high quality of the Unitron's of the 50's and 60's. It convinced me, it took a while, but I finally found a 4" Starfire. And it certainly does match the quality of the Unitron with which I first glimpsed Saturn in the 60's. 

 

Lee


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#3 Scott in NC

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Posted 05 December 2021 - 09:14 AM

Eyal, I’m reasonably sure that that’s been posted here before.  But if so, I don’t know where to find it, and I don’t think it’s possible to repeat the insights of Thomas Back too many times.  So thanks for posting this, as I certainly enjoyed reading it again! :waytogo:


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#4 t.r.

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Posted 05 December 2021 - 09:15 AM

They say there are no “magic” telescopes, only physics can govern what an optic can deliver…and then came Roland and challenged that perception. If my Astro-Physics refractors aren’t magical then at least I have to conclude Roland is a phenom.

Edited by t.r., 05 December 2021 - 09:16 AM.

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#5 Paul Morow

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Posted 05 December 2021 - 11:15 AM

There was an article in S&T during the 90's comparing the excellence of the AP's with the high quality of the Unitron's of the 50's and 60's. It convinced me, it took a while, but I finally found a 4" Starfire. And it certainly does match the quality of the Unitron with which I first glimpsed Saturn in the 60's. 

 

Lee

I used to think about owning a vintage 4” f/15 Unitron for fun and I thought it would be a cool instrument to use. Larger achromats would be much more of a burden to mount and handle for easy set up.

 

After acquiring my Astro-Physics 102 f/8 Starfire it satisfied my 4” Unitron urges. I’m very happy with the Starfire optical performance and it's very easy to deploy for a short observing session. During the winter months my AP102 gets much more use, because I don’t handle the colder temperatures as well as I used to.

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  • AP102_DM4a.jpg

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#6 leonard

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Posted 05 December 2021 - 11:24 AM

They say there are no “magic” telescopes, only physics can govern what an optic can deliver…and then came Roland and challenged that perception. If my Astro-Physics refractors aren’t magical then at least I have to conclude Roland is a phenom.

 

                    An undisputed master of his craft . Seems to not want to go into retirement .

May he have many years ahead producing his masterpieces .


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#7 lee14

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Posted 05 December 2021 - 12:33 PM

After acquiring my Astro-Physics 102 f/8 Starfire it satisfied my 4” Unitron urges. I’m very happy with the Starfire optical performance and it's very easy to deploy for a short observing session. During the winter months my AP102 gets much more use, because I don’t handle the colder temperatures as well as I used to.

Astro Physics.jpg

 

Indeed, the colder temps are increasingly less tolerable...

 

Lee


Edited by lee14, 05 December 2021 - 12:33 PM.

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#8 t.r.

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Posted 05 December 2021 - 02:46 PM

Right on cue…EdTing https://youtu.be/w7bPWiRjozg
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#9 jokrausdu

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Posted 05 December 2021 - 07:28 PM

Hi all,

 

I found this old article by TB from 2003 reviewing AP lenses. I thought it might interest some of you here. If it was already posted in the past then apologies.

 

https://www.csun.edu...n/tmb/tmb1.html

 

More stuff from TB are here.

This really brings back memories. I was lucky to have worked there from early 1990 to October of 1991. I remember so many of those glass types and designs. It is so sad that TMB had passed away. I was able to meet him when he visited with Roland at the shop when we were both much younger guys.


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#10 Jae

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Posted 05 December 2021 - 08:16 PM

I really respected Tom.  My first interaction was on AOL’s Observers Outpost.  I recall posting: Who is  Tom Back ?   As I loved his insights and explanations in various posts where he chimed in.  At which point Tom introduced himself.

 

Not sure I can post this here, if not I or a mod can take it down:

Tom helped clarify some things for me back then on this topic.

 

 

TMBack
May 5, 1999, 3:00:00 AM



to Jae,
>I guess the one scope that was left out although it was not
>sold as an AP, may be the 94mm f/7 Brandon which used
>the AP made lenses.

Glad you brought that up, I forgot about the Astro-Physics
Brandon lenses. The 94mm f/7 and 5-inch f/8 Brandon, both
in Unitron tube assemblies.

>Perhaps you could verify my understanding of it's history.
>I think it first made its appearance in S & T ads in '86 or so

>as a white tube 92mm under the Vernonscope name? Later

>changed to 94mm (same lens but different lens holder?) with
>a blue tube with double rings and lastly a blue tube with a
>single ring.

 

That's right, the first Brandon apochromat was a 92mm f/7,
in a white Unitron tube assembly. As you say, Don opened up
the cell diameter to 94mm and changed the color to blue. Then
to cheapen it up, he junked the fine push-pull cell to an un-
adjustable one. I believe the first ad was in the June 1987 issue
of Sky and Telescope, page 658. This was the best issue of
Sky and Telescope ever, in my opinion, because of the
revolutionary products such as the TeleVue ad for the 20mm
Nagler, the introduction of the Astro-Physics StarFire series, the
92mm Brandon apo, the Uranometria 2000.0 article, the review
of the books "Advanced Telescope Making Techniques, Vol. I
and II," Scotty Houston's great Deep Sky Wonders column (we
all miss him), the Gregory apochromat design, the finest earth
based photo of Mars ever taken by Jean Dragesco, with the
Pic-du-Midi 43-inch and the wonderful Viking color image of
Mars' Valles Marineris image. What an issue!

 

>I thought it was sold until early 90's during the same period as the
>first 4" f/8 Starfires so would it be safe to assume that it was the
>same Starfire design? The color correction would have been a bit
>less versus the 4" f/8 due to it's shorter f/7 design?

 

No, the Brandon 94mm used the same design as the older 5"f/8
and 6"/f8 Astro-Physics lenses. The 94mm Brandon showed a
bit more color than the StarFire lenses. The 5-inch Brandon,
however, did use the 5-inch "StarFire" design. I'm not sure
on the Brandon prices. I think the 92mm was first offered at
$999.

Another Astro-Physics telescope I forgot to mention was a
limited production (1990) of a Super Planetary 6" f/12 StarFire
($2995). It was billed as the ultimate in planetary images for its
size.

Thomas Back

 

can be found here:

https://groups.googl...nD2Vc_hcQ?pli=1


Edited by Jae, 05 December 2021 - 08:17 PM.

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#11 Look at the sky 101

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Posted 05 December 2021 - 08:31 PM

Hi all,

 

I found this old article by TB from 2003 reviewing AP lenses. I thought it might interest some of you here. If it was already posted in the past then apologies.

 

https://www.csun.edu...n/tmb/tmb1.html

 

More stuff from TB are here.

Thanks, 

I just love mine .



#12 turtle86

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Posted 05 December 2021 - 11:13 PM

I used to think about owning a vintage 4” f/15 Unitron for fun and I thought it would be a cool instrument to use. Larger achromats would be much more of a burden to mount and handle for easy set up.

 

After acquiring my Astro-Physics 102 f/8 Starfire it satisfied my 4” Unitron urges. I’m very happy with the Starfire optical performance and it's very easy to deploy for a short observing session. During the winter months my AP102 gets much more use, because I don’t handle the colder temperatures as well as I used to.

 

Beautiful scope! 


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