[APML] Red filters and the need to focus

[Brian larmay <power_windows4789@yahoo.com>]

Does anyone know whether I need to calibrate my lens
for a deep red filter that is not H-a?

Im guessing mine is a #23 since there are no #'s on it
besides R-2.
Customer support is auomated and offers no help.

When does one ned to calibrate, and when does one not
need to calibrate?

Just for another referance, here is a shot taken by
someone else with an R-2

http://astrophoto.westhost.com/Cygnus100mm_Tp.html
I sent this guy an email about i, but it was returned

Brian

=====
Homepage: www.astrobri.com

Location: 
Niagara Falls USA
geographic Longitude = 79W
Geographic Latitude = 43N
Corrected Magnetic Latitude = 53N

__________________________________
Do you Yahoo!?
Yahoo! SiteBuilder - Free web site building tool. Try it!
http://webhosting.yahoo.com/ps/sb/
_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo