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Aug 18, 2015 14:53:04 GMT -5
Post by laurence on Aug 18, 2015 14:53:04 GMT -5
Hi can I ask why Istar do not use FL 51 glass for their 6inch lenes as Lunt do with their 6 inch f8. Looking at Ohara Japan FL 51 gives very good CA correction and very small spot size. This glass would work very well with an 8 inch at F8 and If Iam reading the data correctly it would be an 8inch F8 with correction at about F20 ie very small amount of CA and small spot size. Lunt market their ED 6 inch F8 at just over £3000 for the complete tube with 2.5 inch focusor so what would be the cost of an Istar 8 inch if they us FL 51.
Regards Laurence
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