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Old 07-04-2018, 06:32 PM
Stefan Buda
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Stefan Buda is offline
 
Join Date: Jul 2013
Location: Melbourne, VIC
Posts: 823
Quote:
Originally Posted by Joshua Bunn View Post
No worries Stefan. This page also says it's 2 elements.
http://planewave.com/products-page/t.../#.WshqqIARU0M
Thanks Joshua,

I studied the site and they talk about a pair of lenses which is a bit fuzzy, but I see that their design is f/8, not f/7 as I was thinking, so quite doable with 2 lenses, and they don't even need any aspheric, I'm sure.

But I did not like their misrepresentation of the facts when they are comparing the simulated spot sizes of their CDK with an RC telescope of the same parameters. The CDK is an astrograph while the RC is a telescope.
The RC becomes an astrograph only with the addition of a field corrector.
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