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Manu72

18 Aug 2016 13:33


ERF

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Incepe sa ma intereseze si Soarele ca subiect de observatii si m-am apucat sa trec in revista  diversele modalitati de a face observatii solare - lumina alba (folie, prisma Herschel), HA / CaK (solutii dedicate Lunt/Coronado/Daystar)
Uitandu-ma prin documentatia de la prisma Baader Herschel si prin cea de la Daystar Quark am gasit informatii contradictorii privitoare la montarea elementelor optice in fata diagonalei.

Deci este ok sa punem un filtru uv/ir inaintea diagonalei?
Sunt cei de la Baader exagerat de precauti sau cei de la Daystar sunt inconstienti?


Baader Herschel doc: http://www.baader-planetarium.uk.com/en/pdf/HERSCHEL_PRISM_MANUAL.pdf
In documentatia de la prisma Herschel apare scris (sublinierea imi apartine):

Never mount any filter into the front 2" nosepiece of the Baader Safety Herschel-Prism. During Solar observation the full energy of the Sun reaches the Herschel-Prism unabated. For this reason any additional filtering or reduction of light must never happen in front of the Herschel-Prism since the heat load would be so large that any filter mounted in this place would be shattered immediately (in the focus of an unfiltered 6" refractor at f/10 to f/15 temperatures up to 600°C are being measured).


Daystar Quark doc: http://www.sunfield.ne.jp/~oshima/data/DaystarQuark/QuarkManual.pdf

For  telescopes  under  approximately  120mm  of  aperture,  a  screw  in  UV/IR  cut  filter  can  be  employed in front of the telescope diagonal.  The UV/IR cut filter reflects UV and IR light back out the front of the telescope, reducing temperatures inside.    Do  not  use  a  UV/IR  cut  filter  with  oil  spaced  objective  telescopes,  or  any  telescope  with an integrated rear field flattener 
or Petzval lens.  The UV/IR cut filter must be the first optical element to receive concentrated light.