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Home > Forums > ASTRONOMY EQUIPMENT > Refractors > Message #552394

Re: C102F can't come to focus

Posted by Roland Christen on 10/18/2007 8:34 AM in response to Re: C102F can't come to focus   (1187 hits)
 Prev Post Next Post 

>>"This was one of the first fluorites sold.>>

I can tell you a bit more of the history of this scope. I met Mike Simmons back in 1982 at the Riverside Telescope conference. Mike was the designer of the Edmund Astroscan and the Simak and Astromak, and designed the first GoTo systems for Celestron and Meade.

Mike had done some design work for Celestron, and suggested to them a fluorite doublet using CaF2 and ZKN7 to produce a totally color-free 102mmF8 doublet. I saw the prototype of this scope and the views through this lens was awesome. Zero color on any object, including Venus and Sirius - just like a mirror. He suggested that Celestron work with the Japanese to produce this lens in 4", 5" and 6" versions. At the time, Celestron was working with Vixen, and they were eager to compete with Takahashi and basically out-do them. Unfortunately the Chairman at Vixen was more interested in producing small scopes for kids at reasonable prices, so the design was modified. The expensive ZKN7 design was ditched in favor of using KzFN2 glass, which produced some color error, but was much easier and cheaper to produce. Vixen's chairman felt that the market for a kid's telescope was larger than that for dedicated amateurs, so he never pursued the higher end of the market. He did not care at all about imaging, thus the scope came with 1.25" hardware, and only later was a 2" back added so you could attach a 35mm camera.

The lens, of course was made for Vixen by Canon's Optron division, same place that was making the Tak lenses. The fact that the Vixen was F9 allowed it to have somewhat better correction than the 100mm F8 Tak lenses, and many amateurs in Japan felt that it was a better overall lens than the Tak FC100.

Rolando

Thread:

Subject Posted By Date/Time Hits 
C102F can't come to focus Evan Chan 10/16/2007 8:55 PM 915
Re: C102F can't come to focus John Biretta 10/16/2007 10:15 PM 644
Re: C102F can't come to focus Evan Chan 10/16/2007 10:34 PM 596
Re: C102F can't come to focus John Biretta 10/16/2007 11:39 PM 536
Re: C102F can't come to focus Oren Soffer 10/16/2007 10:16 PM 568
Re: C102F can't come to focus Oren Soffer 10/16/2007 10:24 PM 503
Re: C102F can't come to focus Evan Chan 10/16/2007 10:33 PM 480
Re: C102F can't come to focus Oren Soffer 10/17/2007 1:16 PM 434
Re: C102F can't come to focus Evan Chan 10/17/2007 2:30 PM 458
Re: C102F can't come to focus Floyd Blue 10/17/2007 3:14 PM 551
Re: C102F can't come to focus Evan Chan 10/17/2007 5:21 PM 400
Re: C102F can't come to focus Oren Soffer 10/17/2007 3:27 PM 391
Re: C102F can't come to focus Philip Blanda 10/18/2007 7:03 AM 379
Re: C102F can't come to focus Philip Blanda 10/17/2007 6:55 AM 412
Re: C102F can't come to focus Chase McNiss 10/17/2007 6:34 PM 420
Re: C102F can't come to focus larry thaxton 10/17/2007 8:54 PM 523
Re: C102F can't come to focus Roland Christen 10/18/2007 8:34 AM 1187
Re: C102F can't come to focus Paul Leuba 10/19/2007 12:19 PM 588
Re: C102F can't come to focus Paul Leuba 10/19/2007 12:24 PM 454
Re: C102F can't come to focus Evan Chan 10/19/2007 1:15 PM 395
Re: C102F can't come to focus Paul Leuba 10/19/2007 4:40 PM 414
Re: C102F can't come to focus Evan Chan 10/19/2007 4:53 PM 370
Re: C102F can't come to focus Paul Leuba 10/21/2007 1:57 PM 351
Re: C102F can't come to focus Roland Christen 10/19/2007 2:34 PM 603
Re: C102F can't come to focus larry thaxton 10/20/2007 10:04 AM 459
Re: C102F can't come to focus Evan Chan 10/20/2007 10:46 AM 325
Re: C102F can't come to focus Paul Leuba 10/21/2007 2:14 PM 336
Re: C102F can't come to focus John Powers 2/27/2008 4:59 PM 288
Re: C102F can't come to focus Jake Jacobson 10/18/2007 10:09 AM 356
Re: C102F can't come to focus Evan Chan 10/18/2007 10:18 AM 348
Re: C102F can't come to focus Jake Jacobson 10/18/2007 11:34 AM 359
Re: C102F can't come to focus Jake Jacobson 10/21/2007 10:08 AM 346
Re: C102F can't come to focus James Siska 10/18/2007 10:46 AM 428

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