Re: [APML] Solar filter question

[José Carlos Diniz <dinizfam@uninet.com.br>]

Michael
I have the filter Thousand Oaks Tipo II Plus 8 " and recently I acquired
Baader filter ( ND-5 0.00001 transmission ), that was placed in a the same
assembly ( 8" mount). I photographed the Sun in the primary focus of a LX200
8" f/10 and with ocular projection (20mm and 7mm) using the film TP to 125
ISO and developed in HC 110 using dilution B.They were made varied and the
same exposures for the two filters ( the exposures was calculate using
Michael Covingtonīs software ). The comparative study showed that Baader is
2,5 faster stops than Thousand Oaks.
Baader  shows a more contrasted image and better definition ,  visual and
photographic.The image of the Baader filter is white and the one of
Thousand Oaks yellow.
My two cents
J.C.Diniz
http://www.geocities.com/dinizfam





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