Jay,
Can't speak from experience about the "auto" part of your question. I
use a JMI NGSF Motofocus and use its control paddle. The control through
the LX keypad I find less expressive so to speak.
Have tried fine focusing using a thin stick accross the middle of the
dew shield whose diffraction spike can be used for a good focus, then
went to a three hole mask, then to using the focus routine in MaxIm DL.
The three hole mask is useful for determining when you are intra or
extra focused as the third hole will move above or below the other two.
Paul Gitto has a good article on this mask on his web page.
http://cometman.com/Mask.html
Using a combination of star brightness and exposure settings that keep
the pixel value to less than maximum, go from 4 x and 2 x binning to an
unbinned image, refining each as well as you can both in appearance and
by maximizing the pixel value. I find that enlarging the final focus
images also helps.
It would be quite difficult to obtain a fine focus using only mirror
focusing, hence the Motofocus. It also requires very steady seeing to
determine just how well you can ultimately do i.e. very minimal
scintlation visually.
At this point I really enjoy the 416XT. Wishing you the same.
Regards,
Eric

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