Metric Variable Moose writes:
<<When making the below shots, I measured the distance from focal plane marked
on the camera to the point I carefully manually focused on. Just a rough
measurement, but I think accurate within a mm or so, two at most - 155 <<mm
<<Then I checked the EXIF - 180 mm.
<<I have no information why the difference. Could be the accuracy is "x% ±30
mm", which is quite OK, except at really short distances. Or the lens may
report that it has hit closest focus, and the camera assumes that is the
<<published 180 mm, as opposed to what this particular lens is doing.
<<Just a reminder that not all is as reported in this wonderful digital world.
<<Keep your wits about you. :-)
I strongly suspect it is just the lower accuracy/precision as a consequence of
using stepper motor counts to estimate focusing distance to report in exif.
The error is greatest at near and long focusing distances. Panny doesn't even
bother unless they have changed there ways, which I really don't like at all.
Ahh, here is one link:
http://wetpixel.com/forums/index.php?showtopic=52938
Keep in step and report same, Mike
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|