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Old 14-01-2012, 09:48 PM
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gregbradley
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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 View Post
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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