RE: [APML] 35 mm Camera & Focuser

["Serge Theberge" <serge.theberge@wti.on.ca>]

John/Bill,

I just called Vixen this afternoon for more info on the new R200SS.  All the
fellow knew is that it has a longer focuser than the previous model.  He
will get back to me with more technical details within a week. He also
mentioned that they have an off-axis guider in their new catalog ~ $140US.
He will send me information on that as well.  When I receive it I will post
the information.

Serge

> Lumicon 2 inch Newtonian Off Axis Guider. *But* you might 
> need something different because at f/4 you will need the 
> coma corrector and I am not sure what the Vixen specifics are 
> on theirs and how it mounts. Lumicon has a coma corrector 
> that threads into the bottom of the OAG. You can
> <- snip ->
> 
> Bill,
>     The Vixen *was* designed to be used with a guidescope - 
> there wasn't enough backfocus for an OAG. Most of the images 
> you will see were done that way, as there weren't many other 
> options. Vixen have redesigned the scope a bit, according to 
> their web site. It's now green, has a bigger finder and they 
> have done "something" to the focuser. What that is exactly 
> isn't clear from the description, but it appears that they 
> have extended the back focus a bit or increased focuser 
> travel. If there is 7/8" of in travel from focus, then a 
> Lumicon OAG would work. You just need to find one that is 
> 60mm in diameter......
>     The Lumicon flattener is a bit of a mixed blessing. I 
> have one that I used at f4.5, which it was apparently 
> optimized for. It got rid of coma all right, but substituted 
> massive amounts of spherical aberration. So bad, that I could 
> never get it focused. Even under a knife edge, it never 
> nulled out. It was threaded on to a Lumicon OAG for correct 
> spacing, but in the end I was getting better images from my 
> f6 Newtonian. Your mileage will probably vary, but those were 
> my results.
> 
> John Mirtle
> Calgary, Ab. Canada
> 
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> 


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