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Re: [APML] Film and OAG Questions



Thanks Bill, Duncan, and Chris!  The sky cleared last night so I gave it a shot.  I could not get it to focus using the star diagonal and 2X Shorty barlow.  I'm going to check it out in the day to see if I can figure it out.  I guess I'll just have to deal with the 3X Prism diagonal for now.  As for the Fuji film, it's called Fujicolor Press DX 800 ISO.  Since the sky was clear I thought I'd give it a test.  I took various exposures with my 55mm lens @ f/4 and a few prime focus shots through my 80mm f/6 achromat.  I should have them back by Wednesday and will post my results.
 
Gary
----- Original Message -----
Sent: Monday, October 11, 2004 8:46 AM
Subject: RE: [APML] Film and OAG Questions

Gary, welcome to the world of off axis pain and suffering.  I use a 2x barlow for my visual guiding, 3x is too much and makes the stars much too faint.  Just remember to calculate your maxium guiding tolerance and be able to see it clearly in the guiding eyepiece is the key.  so if your tolerance is 5 arcsec, know what that looks like by spliting doubles in the guiding eyepeice.  Try epsilon lyra for example.
 
Chris
-----Original Message-----
From: astro-photo-bounces@seds.org [mailto:astro-photo-bounces@seds.org]On Behalf Of GARY HATFIELD
Sent: Saturday, October 09, 2004 6:17 PM
To: APML
Subject: [APML] Film and OAG Questions

Hello,
    I bought a roll of Fuji Superia 800 and was shooting with it at a festival today.  I didn't use all 36 exposures and was wondering if this film is any good for astrophotography.  I've forgotten what it actually said on the film cannister itself, but on the film tube it came in it reads--Fuji Superia CZ135-36 800 ISO.  Just wondering if it's worth my time to finish the roll under the stars or not.
    I have a Lumicon 2" Easy Guider and the (Lumicon) recommended 3X Prism Diagonal.  I guide with a 10mm illuminated reticle.  I'm using a 480mm f/6 80mm achromat.  My problem is not so much in finding a guidestar (although that is a challenge at times), but having one bright enough that I can actually see well enough to guide with, without having to use averted vision.  Is there a reason for using a prism instead of a star diagonal?  I realize having a 3X magnification is going to make the guiding easier and more accurate, but would I get brighter guide stars by using a star diagonal and 2X barlow?  Would I be able to focus the guidestar with this set-up?  The sky here is socked in or I would try it out.  I'd appreciate any thoughts or knowledge anyone might bestow upon me.
 
Gary 
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