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Re: [APML] The Van Slyke "Slider" in detail



From: "Tony Hallas" <tonyhallas@foothill.net>
astro-photo@seds.org<astro-photo@seds.org
Subject: Re: [APML] Van Slyke "Slider"
Date: Saturday, January 19, 2002 9:49 AM
 
Hello,
 
     No offense to Paul, but you might miss the enormous significance of his product... so from the viewpoint of someone who's "been there" I have summed up why this deserves your attention.
 
1.  Trying to find a dim, obscure object? No sweat... pull in the mirror, put in a 35 Panoptic (with a filter if need be) and locate it or a dim star field no sweat. The ocular holder can be adjusted so that its center is the center of the photographic field.
 
2.  Need to knife edge your focus? No sweat... pull in the mirror and center a good star in the field... it will be in the center of your knife edge device when you slide the mirror out.
 
3.  Find a guide star? Piece of cake... I use the STV. Just move the small mirror around the field till a nice one shows up on the screen and lock the mirror down. NOTE that once the STV is focused with the camera knife edged (or CCD) it never has to be removed! The STV can guide in any alignment and you find the guide stars by looking at the screen. It will always be in focus when the camera is in focus. And... no more "compromises" because there simply wasn't a guide star in the "right" spot!
 
4.   Want to guide on the stellar head of a comet? Easy with this... just rotate the pick-off mirror till you have it... this device can see 100% of the photographic field!
 
5.   Want to check out the seeing before shooting? Just slide the mirror in... likewise if you want to take a break and do a little viewing of the planets or whatever... nothing has to be taken apart... you just move the mirror in and out!
 
6.  Need to make an airtight chamber for nitrogen? Paul can modify the camera connection tube so all you have to do is glue a 52mm multi-coated UV filter into the front and drill and tap a small quick-disconnect nipple into the side of the tube.
 
     When I think of all the years I have been struggling with clunky OAG systems... often too burned out to go through the tedium of taking everything apart,  rotating the OAG, then back to see if the object is still there after I have a guide star, then off to knife edge focus, then back to the object, then focus the STV... arghhhhh!
 
      Tony