Re: [APML] Focusing OM-1 - but what about the Nikon F2?

["Stuart Heggie" <stuart.j.heggie@sympatico.ca>]

Thanks John! More to consider.
Stuart
----- Original Message ----- 
From: "John Mirtle" <spampit@shaw.ca>
To: "'Discussion of Film Astrophotography'" <astro-photo@seds.org>
Sent: Saturday, November 13, 2004 12:39 PM
Subject: RE: [APML] Focusing OM-1 - but what about the Nikon F2?


> Stuart,
> I can only comment based on my personal experience. With my Olympus
> 1-8 fine matte screen, the magnifier works great from 1200mm to 3900mm. Alan
> is having good results at 820mm on his FS-102. When I started messing around
> with my 180mm telephoto many years ago, I found that it was *not* accurate
> enough. I also found that a knife edge was very touchy at such short focal
> lengths, especially at f2.8. This is why I went with the 2 hole mask. I
> would suspect that your 400mm would be in the same league - too fussy for a
> magnifier but it shouldn't be too hard to use with a knife edge. The
> magnifier seems to work best at long focal lengths and with slower focal
> ratios.
> Of all the knife edge focusers I have tried, I agree with the other
> comments - the Hutech unit rocks! At $20, the Lumicon option is sometimes
> worth a shot - if you can figure out how to mechanically couple the
> magnifier to your camera. For short FL's, there is something I have been
> meaning to try. How about a 2 hole mask *and* a magnifier? It would be much
> easier to see when the 2 star images overlap. Probably not as accurate as a
> knife edge but it wouldn't cost much to try it out!
> 
> John Mirtle
> Calgary, Ab. Canada
> 
> -----Original Message-----
> From: astro-photo-bounces@seds.org [mailto:astro-photo-bounces@seds.org] On
> Behalf Of Stuart Heggie
> Sent: Friday, November 12, 2004 9:27 PM
> To: Discussion of Film Astrophotography
> Subject: Re: [APML] Focusing OM-1 - but what about the Nikon F2?
> 
> Yes - the wisdom of John Mirtle is not to be discounted! John, do you think
> it will work to focus
> directly on the focus screen with the viewfinder removed from my Nikon F2?
> 
> Stuart
> 
> 
> _______________________________________________
> 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