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mihaig

12 Apr 2019 03:12



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Intre timp cred ca am gasit explicatia :

" You'll have to use a Ronchi grating at Cass focus with the telescope held stationary and aimed at Polaris, and experiment a little with mirror spacing until you find the best spacing, one that hopefully gives nice straight "jailbar" Ronchi lines on either side of focus.  If the mirrors are too close together, you'll see overcorrected Ronchi bands bowing closer together at the top and bottom of the pupil.  Undercorrected spherical aberration results if the mirrors are too far apart, and the bands will bow farther apart at the top and bottom of the pupil."

In plus faptul ca doctorul de ochi mi-a spus azi ca trebuie  sa incep sa port si ochelari de distanta cu ceva corectii cilindrice :cry: 

https://www.cloudynights.com/topic/568948-building-a-4-f15-dall-kirkham-cassegrain/

Mircea, nu mai pot colima nimic deocamdata...e bucati :)