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Mircea Pteancu

06 Iul 2008 16:54



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''Sa revenim la '48 don prefect''. Iata ce zice Bob May despre luneta sa de 108 mm F=4860mm, F/45, si care nici macar nu este dublet,este lentila simpla.Inainte ca cineva sa ma ia  la bataie ,trebuie sa stiti ca luneta respectiva a luat  premiul 2  la Conventia din 2001 de la Stellafane:
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Actually, you're pretty right there Richard.  With CCD cameras,
you really need the red end of the spectrum more than the UV end.
I do like looking at lens design with a more balance towards the
blue as this will decrease the blue haze more at the lower powers
and the loss of focus at higher powers isn't that great,
especially on longer focal ratio scopes that usually get built.
My 200" refractor (4.25" F45 singlet lens) has huge color
problems - so much so that you focus the scope by making the red
and blue hazes the same size - actually ends up being very nice
in the midrange of the spectrum, so much so that I can easily see
Mercury as a nice sharp shape when other scopes are showing a
blob wiht a bit of wings on it.  With it, I've also seen some of
the Canals of Mars that Schapelli saw.
Bob May
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Iata linkul la care puteti vedea luneta.

http://stellafane.org/images/2001_conv/scopes/scope52d.jpg

As mai vrea sa adaug faptul ca am mai citit despre o luneta similara de 3'' si care la excelenta optica a batut la popoul gol un Dall-Kircham de 11cm.Mircea