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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   (1305 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 938
Re: C102F can't come to focus John Biretta 10/16/2007 10:15 PM 655
Re: C102F can't come to focus Evan Chan 10/16/2007 10:34 PM 616
Re: C102F can't come to focus John Biretta 10/16/2007 11:39 PM 551
Re: C102F can't come to focus Oren Soffer 10/16/2007 10:16 PM 594
Re: C102F can't come to focus Oren Soffer 10/16/2007 10:24 PM 521
Re: C102F can't come to focus Evan Chan 10/16/2007 10:33 PM 496
Re: C102F can't come to focus Oren Soffer 10/17/2007 1:16 PM 455
Re: C102F can't come to focus Evan Chan 10/17/2007 2:30 PM 480
Re: C102F can't come to focus Floyd Blue 10/17/2007 3:14 PM 565
Re: C102F can't come to focus Evan Chan 10/17/2007 5:21 PM 412
Re: C102F can't come to focus Oren Soffer 10/17/2007 3:27 PM 403
Re: C102F can't come to focus Philip Blanda 10/18/2007 7:03 AM 390
Re: C102F can't come to focus Philip Blanda 10/17/2007 6:55 AM 428
Re: C102F can't come to focus Chase McNiss 10/17/2007 6:34 PM 439
Re: C102F can't come to focus Larry Thaxton 10/17/2007 8:54 PM 550
Re: C102F can't come to focus Roland Christen 10/18/2007 8:34 AM 1305
Re: C102F can't come to focus Paul Leuba 10/19/2007 12:19 PM 614
Re: C102F can't come to focus Paul Leuba 10/19/2007 12:24 PM 478
Re: C102F can't come to focus Evan Chan 10/19/2007 1:15 PM 412
Re: C102F can't come to focus Paul Leuba 10/19/2007 4:40 PM 435
Re: C102F can't come to focus Evan Chan 10/19/2007 4:53 PM 383
Re: C102F can't come to focus Paul Leuba 10/21/2007 1:57 PM 373
Re: C102F can't come to focus Roland Christen 10/19/2007 2:34 PM 632
Re: C102F can't come to focus Larry Thaxton 10/20/2007 10:04 AM 486
Re: C102F can't come to focus Evan Chan 10/20/2007 10:46 AM 341
Re: C102F can't come to focus Paul Leuba 10/21/2007 2:14 PM 356
Re: C102F can't come to focus John Powers 2/27/2008 4:59 PM 309
Re: C102F can't come to focus Jake Jacobson 10/18/2007 10:09 AM 381
Re: C102F can't come to focus Evan Chan 10/18/2007 10:18 AM 362
Re: C102F can't come to focus Jake Jacobson 10/18/2007 11:34 AM 378
Re: C102F can't come to focus Jake Jacobson 10/21/2007 10:08 AM 360
Re: C102F can't come to focus James Siska 10/18/2007 10:46 AM 443

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