Re: [APML] OT: Hartmann Mask

[<apml@andreasroerig.de>]

Hi Nicola,

thick cardboard ist ok. To protect it against moisture simply paint it
black with water resistant paint. I made Hartmann masks for a variety
of scopes and I am using them for years now. No problem so far. But you
could also use thin plywood (also painted black) or plastic.

I have cut two holes almost as far as possible from the center. The
holes should be as small as possible but big enough to provide a star
image that is bright enough for focusing. Sometimes three holes in
triangle shape are recommended but I prefer two round holes.

I have used these masks in combination with my trusty Canon A1 SLR and
they also provide signifficant help when focusing a DSLR or a CCD
camera.

Best regards
Andreas


:=============================
: Andreas Roerig
: http://www.andreasroerig.de

centaurus_a@virgilio.it schrieb am 05.07.2004, 10:50:08:
> Hello All,
> 
> I'm very bad at do-it-yourself things but, is there anyone or you knwo any
> link on how to build a solid hartmann mask? The one I did once was made
> by cartoon and outside in the night it became floppy....:-(
> And..which is the best shape to dig for the mask?
> 
> regards,
> Nicola
> 
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