Robofocus units are often used like that with lenses as well.
It would also reduce the backfocus needs. The PDF takes up at least 25mm.
Greg.
Quote:
Originally Posted by DavidTrap
Hi Greg,
Just checked out the PDF focuser - certainly looks like the ducks guts for focusing these lens.
I will be trying a more humble option - its a belt driven focuser that rotates the manual focus ring of the lens. By its nature it's geared down, and can rotate in small steps, so hopefully it will achieve a satisfactory result when combined with a Bahtinov mask and a bright star.
Cheers
DT
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