[ATM] mirror cells and parabola...

[hermit]

Stephen Koehler wrote:
> Norm,
>
>   
>> I've been thinking about figuring too, and running some numbers...it seems
>> to me that parabolizing an f/5 doesn't really buy me much.  Well at least as
>> far as my eyeball is the limiting factor in the system.
You know your eyeball.

>>   The difference
>> seems so miniscule that my eye wouldn't know the difference, tho i could be
>> doing the math wrong as far as the Raleigh standard is concerned....

This is wrong.

>>   Does
>> the correction help in other ways??? chromatically...etc.?
>>     
Not on a single surface as far as I know.

>
> Can you elaborate on your reasoning led to the conclusion that leaving
> a 12" f/5 at a sphere was acceptable?  The conclusion is wrong.
> Perhaps it would be instructive to see where the error crept in.
>
>   
Ken Lowther