Quote:
Originally Posted by ptc
Greg: square filters that don't have blackened edges will give clearly visible artifacts in the flats. Most pronounced in the green, clear, [OIII] and sometimes blue filters. Typically not so bad with Red and Halpha
you ought to blacken the edges. See this:
http://www.edmundoptics.com/techSupp...ned-optics.pdf
ciao
rdc |
Hi Richard,
I typically coat the edges of my felt pen with a black sharpie pen. Not sure if I did for those on the Tak BRC though. Was a while ago. Perhaps they weren't, as you say.
Cheers,
Greg.