[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]

Re: [APML] OAG for 2.7" focuser



I didn't know they had a 2.25" OAG. I have considered putting my 2.7" OAG and focuser on your newt. It would eliminate any prism shadow concerns and let me guide at any angel.
Bobby Middelton
 
----- Original Message -----
Sent: Monday, December 03, 2001 8:23 PM
Subject: Re: [APML] OAG for 2.7" focuser

Hi Guys,
 
    For what it's worth, I use the Lumicon 2.25 OAG with my set up... my reasoning for this is to get the prism far enough away from the light cone hitting the 35mm film so I can go searching anywhere for a star and not worry about the shadow hitting the film. I also have a multicoated Hoya clear filter screwed into this assembly to create a chamber so I can use nitrogen while I expose.
On this topic, I bought an expensive needle valve... highest quality... and use this to meter the nitrogen. One can easily hear when the first tiny trace of nitrogen is escaping... once the camera is purged it takes only the smallest amount to keep ambient air out. My tank now lasts for months instead of weeks. (especially when it is constantly raining  ...)
     What I would love to see someone develop would be an OAG with bearing races instead of these clunky set screws.
That would be worth its weight in gold...
 
        Tony