Re: ATM Astroscan Houghton

[Gary Seronik <gseronik@netway.com>]

Hi John:

At 09:58 AM 12/10/2002 -0800, John Swenson wrote:
>
>Gary, Bob et al, on MY astroscan when star testing I get severe 
>spherical aberation and a Ronchi test (scope still in tact, ie going 
>through the front "window") shows almost straight lines, they are 
>slightly bent near the edges. This is NOT an 1/8 wave parabolic or a 
>properly done schmidt newt. Testing the refelctions off the front glass 
>it looks like a pretty flat piece of glass.
>
>As far as I can tell this is a pretty good f 4.2 spherical mirror with a 
>  window in front, which to me sounds like a prime candidate for 
>converting to a Houghton. Which was the question in the first place :)

Two follow up questions if I may:

1.  You're sure that this is an actual Edmund Astroscan and you're not
referring to the Bushnell knock-off (which doesn have a spherical primary)?
2.  Assuming it is an Edmund, how recently did you purchase it?

Thanks,
Gary Seronik