[billdan (Bill)]

Hi guys,

I read a recent thread somewhere, and an AP chap said it has been 5 years since he looked through an eyepiece. It got me to thinking why not ditch the secondary and use a slimline camera at prime focus.

The Atik 420 and QHY8L are around 60mm diam, smaller than most secondarys on a 10in plus scope. So with an appropriate spider and focuser, should'nt you get brighter images.
Other advantages I see are No Vignetting and simpler collimation.

Disadvantages would be
a) limted to OSC as a filter wheel would create a larger shadow.
b) Could'nt use OAG, would have use a guidescope with no flexure.
c) Have to use skinny cables running along the top of the spider

I did search on other forums and I could not find anyone using this technique so may be there are other pitfalls I haven't envisaged.

I was going to refurbish this old beast and give it a new life.
Any thoughts?

Bill