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Old 30-04-2007, 05:44 PM
jase (Jason)
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Join Date: Sep 2006
Location: Melbourne, Victoria
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Quote:
Originally Posted by allan gould View Post
It may be a cheap way to broad band H alpha imaging?
Broadband H-alpha imaging would simply be using a red filter. Traditionally H-alpha filters come in 4.5nm through to 13nm band sizes. There is nothing broad about these band sizes. They all transmit a very narrow window of light. Producing and testing narrowband filters isn't cheap, so I can't imagine a "so called" cheap alternative especially combining two broadband filters as a light cutoff mechanism.
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