where to find Refractor Lens?
- orly_andico
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- orly_andico
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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.
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.
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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
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
- orly_andico
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I am not sure whether the ISTAR new lens cell will perform like Semi APO or ED.......orly_andico wrote:3X reduction in CA isn't so bad... that's "almost" ED performance (ED is 5-10X reduction over an achromat).
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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This is the spot diagram extracted from the pdf:
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email: gary[at]astro.sg
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"The importance of a telescope is not how big it is, how well made it is.
It is how many people, less fortunate than you, got to look through it."
-- John Dobson.
email: gary[at]astro.sg
twitter: @astrosg
"The importance of a telescope is not how big it is, how well made it is.
It is how many people, less fortunate than you, got to look through it."
-- John Dobson.