Matthew Hunt wrote:
On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza
<[email protected]> wrote:
Examples:
100mm lens focused at infinity -> focusing ring is set at 15-20m;
50mm lens focused at infinity -> focusing ring is set at 7-10m;
28mm lens focused at infinity -> focusing ring is set at 3m!
I used the "Table Output" feature of the following web page for 100mm
focal length and "Extension Length" checked:
http://www.openphotographicsociety.org/index.php?option=com_content&view=article&id=646&Itemid=108
An extension of 0.306mm corresponds to a focus setting of 32.9 m.
That's somewhat more than 15-20m, but it seems like your measured
register offset of 0.35mm could be a significant contributor to the
problem you encounter.
Similarly, for a 50mm focal length, 0.383mm extension corresponds to
6.63m focus setting. Quite consistent with your findings.
Many thanks! I believe that explains the problem.
Dario
--
PDML Pentax-Discuss Mail List
[email protected]
http://pdml.net/mailman/listinfo/pdml_pdml.net
to UNSUBSCRIBE from the PDML, please visit the link directly above and follow
the directions.
