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Old 14-09-2017, 02:44 PM
glend (Glen)
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glend is offline
 
Join Date: Jun 2013
Location: Lake Macquarie
Posts: 7,121
For some years iStar has produced achromat objectives with significant reductions in CA due to the glass used. IStar refer to these as: Anastigmatic objectives yielding reductions in CA of between 30 and 50%.

http://www.istar-optical.com/objective-lenses-ii.html

I built a 127mm f12 refractor using iStar's R30 127mm objective, which yields CA performance equivalent to a f15 scope. As you can see by the chart in the previous post, once you get into the green area CA is no longer an issue.
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