On 14/10/06, Gonz <[EMAIL PROTECTED]> wrote: > I bet you'll find that due to mass production, the sample variation is > not significant. Even though the "A" lenses might be calibrated that > way, its still the same basic concept. I've found that while using the > aperture ring is more accurate even for "A" lenses, its not off by that > much, maybe 1/3 stop on worst case. Its probably similar to the K/M > lenses. Besides you could autocalibrate your lens and write the table > back into the firmware. Problem solved.
There was a post on the dpreview forum a couple of weeks back, someone had mapped the accuracy of multiple exposures made using the lens aperture setting vs the on body aperture setting for a number of lenses. The results were plotted and the deviation of accuracy when using the on camera aperture selection was in the order of double, but it wasn't consistently negative or positive so it couldn't be mapped out in reality. Johns suggestion of positional feedback on the actual in lens aperture mechanism is likely the most practical way that it could be remedied in the future. Currently the more complex the aperture activation lever couplings/cams the more error there is when aperture is set by the body. When I shoot panos now I prefer to use lens based aperture selection due to this fact. -- Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://home.swiftdsl.com.au/~distudio//publications/ Pentax user since 1986, PDMLer since 1998 -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
