To: John Swenson , atm list 
From: Gary Seronik 
Reply-To: Gary Seronik 


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

--- BBBS/NT v4.00 MP