Re: [APML] Tech Pan/Ha filter focusing

["Jim Ives" <flyboy9990@earthlink.net>]

Scott,
    I would agree with Jim J. on this.  I used John's focusing technique for
all my camera lenses and it worked like a charm.  It's the best way to do
it.
Jim Ives
----- Original Message -----
From: "Jim Janusz" <jjanusz@dc.rr.com>
To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
Sent: Wednesday, June 04, 2003 4:57 PM
Subject: Re: [APML] Tech Pan/Ha filter focusing


> Hi Scott,
>
> I would say no.  The Ha filter will shift focus towards the Ir as well as
> the glass thickness.  Focusing for Ha is best done photographically using
> some type of scale on the instrument.  See John Mirtle's page for a great
> article on this.
>
> http://members.shaw.ca/jmirtle/ha.htm?
>
> Sorry.
>
> Jim
> ----- Original Message -----
> From: "Scott Hammonds" <capella@creatorsview.com>
> To: "Discussion of Film Astrophotography" <astro-photo@seds.org>
> Sent: Wednesday, June 04, 2003 11:47 AM
> Subject: [APML] Tech Pan/Ha filter focusing
>
>
> > Hey Tech Pan Junkies,
> > This question may have been addressed before, forgive me if it has and
> > for being too lazy to search the archives.
> >
> > I assume one day the weather will actually be clear again and I'll be
> > able to shoot some film. I just ordered a 48mm Ha filter to use prime
> > focus with my 4" scope. Can I use my IDAS filter to focus and then just
> > replace it with the Ha filter and achieve accurate focus?
> >
> > Any help would be greatly appreciated.
> >
> > Thanks,
> >
> > Scott Hammonds
> >
> >
> >
> > _______________________________________________
> > Astro-Photo mailing list
> > Astro-Photo@seds.org
> > http://seds.org/mailman/listinfo/astro-photo
> >
>
>
> _______________________________________________
> Astro-Photo mailing list
> Astro-Photo@seds.org
> http://seds.org/mailman/listinfo/astro-photo
>

_______________________________________________
Astro-Photo mailing list
Astro-Photo@seds.org
http://seds.org/mailman/listinfo/astro-photo