On Tue, Mar 15, 2011 at 6:02 PM, Dario Bonazza <dario.bona...@virgilio.it> 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. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
