AW: [APML] Achromats?

[a.roerig@t-online.de (Andreas Roerig)]

Hi everybody,

this is an interesting discussion. I own one of these cheap china
achromats. It is a 120/600mm. I tried to do some CCD imaging with it.
But when it comes to tricolor or LRGB images I have severe trouble with
the blue halos that Michael mentioned in his mail. You can see an
example here:

http://home.t-online.de/home/a.roerig/g2/m13lrgb.htm

I focused for each channel, but the blue simply did not focus. First I
thought this may be due to IR leaking in the blue filter of the
Astronomik filter set. So I tried with a Vixen/IDAS LRGB filter set with
the same result. I always get those dramitc blue halos.

For monochromatic imagain (i.e. H-alpha) such an achromat may be ok. At
least I tried this as well. The result can be seen here:

http://home.t-online.de/home/a.roerig/g2/dwb111.htm

Best regards
Andreas


:=================================
: Andreas Roerig
: Bahnhofstr. 16
: 65599 Dornburg-Wilsenroth
: Tel. 06436/28137
: http://home.t-online.de/home/a.roerig/index.htm
: (Letzte Aktualisierung: 02.07.2002)




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