where to find Refractor Lens?

Wanna make a scope? Or better still, grind a mirror yourself. Or, you have some good tips in making a really useful accessory? This is the place to show what your hands can do...
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orly_andico
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Post by orly_andico »

hmm. that's interesting. the CGEM DX is "just" a CGEM with a 2.75" tripod. i may have this scope in my future. :-)
kimo
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Post by kimo »

I had contacted some Lens supplier. They quoted me so expensive that I easily can buy complete ED refractor.
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orly_andico
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Post by orly_andico »

well was that lens supplier APM? if yes then I'm not surprised, those are Russian LZOS glass.

there is this somewhat scary lens supplier in China.. check out ebay seller "great-eye" he offered a 106mm ED triplet OTA for $700 USD some time back. Said it was same as the AstroTech 106LE. Maybe from the same factory.
James Ling
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Post by James Ling »

Hi KIMO.

I am going to place an order with ISTAR for their 150mm F5 R50 or R75 doublet....

If you don't mind to wait for 3 months, you can also be the first few to order this newly improved doublets from ISTAR that some people think its CA should be same as F15 and above, with 75% reduction on the CA....

REgards

James Ling
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orly_andico
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Post by orly_andico »

3X reduction in CA isn't so bad... that's "almost" ED performance (ED is 5-10X reduction over an achromat).
James Ling
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Post by James Ling »

orly_andico wrote:3X reduction in CA isn't so bad... that's "almost" ED performance (ED is 5-10X reduction over an achromat).
I am not sure whether the ISTAR new lens cell will perform like Semi APO or ED.......
But I was shown the spot diagram for the 150 F5 R50.
perhaps someone is able to interpret from the spot diagram......

REgards

James Ling
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Gary
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Post by Gary »

This is the spot diagram extracted from the pdf:

Image
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