Quote:
Originally Posted by PKay
Hi Andy
Question: What is a N2 filter? I have no idea.
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Ionized Nitrogen - the Nitrogen emission line is very close to Ha.
Ha is 656.2nm. N2 is 658.4nm - most Ha filters 5nm or more include the N2 signal, so only the narrowest (and most expensive) of Ha filters, 3nm allows one to seperate these two.
My BBW56 image was composed of Ha, N2 & S2, basically light that is red, redder and even redder still! So much careful thought & processing was required to create a tricolour NB image.
You can read more about N2
HERE
Cheers
Andy