[ATM] Auto Collimation Flat - not cored

[William Marriott]

Shane;

I collimated my 6" MakNewt using the secondary, and
knife test through the eyepiece. I had best success
with the flat right up against the end of the
corrector cell.

Bill
--- Shane LaPierre <shane at ct-astronomer.com> wrote:

> I've got a good 8" optical flat and would like to
> use it 
> as an autocollimator.  It is not coated, and is not
> cored. 
>  I had thought about using it as a reference to make
> my 
> own flat, but is there a way to use it and not
> aluminize 
> it in the center, or remove the coating in the
> center so I 
> can place a knife-edge @ ronchi in the center?  I've
> also 
> thought about getting a good diagonal mirror and
> just 
> moving it 90-degrees off - as in a newtonian.  Let
> me know 
> your thoughts.
> 
> Thanks,
> Shane LaPierre
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