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Source for Flats for Folded Refractor

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#1 Tucker512

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Posted 11 October 2019 - 01:09 PM

Anyone know of a good source for (not crazy expensive) flats in the 3-6" range for folding a long refractor?  I've seen Newtonian diagonal flats used for this, but that seems like a waste of the glass outside the nearly circular footprint of the beam when the mirrors are only tilted 10-15 degrees.

 

Thanks!

Scott



#2 Oregon-raybender

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Posted 11 October 2019 - 01:57 PM

Secondary flats can be your cheapest source. You pay for the overall size or area of the flat.

The low angle you are using round will be fine. But it depends on your size requirements.

Remember the flatness has to be better than the lens you are using in the total system.

Each optical surface you add down grades the system. 1/10 wave or higher will cost you.

 

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#3 Steve Dodds

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Posted 11 October 2019 - 02:33 PM

I have some round Zerodur 1/20 wave flats. 2" to 6"  PM me with what size you want and I will give you a quote.

 

Steve




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