Derby Chang wrote: > Doug Franklin wrote:
>> But [trap focus] only works with MF lenses or AF lenses that turn off >> all their (digital?) electronics when in MF mode. For example, my >> SMCP-FA* 200/2.8 won't do it in any (lens) mode. My Sigma APO 400/5.6 >> Macro, though, will do trap focus when it's set to MF mode. >> > It would be cool to be able to use AF lenses and select a different > focus zone instead of dead centre. Yes, it would. Especially when shooting stuff that's moving quickly through the field of view. I have found that I have to "bias" the AF point to get the focus where I want it on that sort of stuff. I believe the issue is "lock time": the time from when the connection at the shutter release completes to the time that the shutter actually moves and the sensor/film get exposed. This time is short, but it's there, and you can see it in where the plane of focus lands in the image. -- Thanks, DougF (KG4LMZ) -- 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.
