Non Euclidean Moose writes:
<<You make an assumption of inadequacy without evidence.
<In round numbers the EM-5 11 IS provides about 3 stops stability over 1/FL rot
<(rule of thumb) on dpreview test at 24mm and 200mm.
NEM continues:
<<That the effectiveness is the same at both FL extremes should be a clue that
its design is sufficient to deal with long FL magnification of camera movement.
My own <<experience says it is certainly up to 300 mm. That the camera allows
setting FL up to 1000 mm, it's not an unwarranted assumption that that is the
design end point. <<Certainly a couple of quick tests shots with the 500/8 look
like the IS worked, but how to tell which parts, I don't know.
One may speculate forever on whether a particular engine will propel a
particular car through the 1/4 mile in less than a particular time. But none of
that matters after the test has been made. The theoretical speculation must
adjust to the experimental results.
It is certainly possible in theory, given adequate motion sensing, sensor
movement speed, accuracy and travel, for IS to fully compensate for geometry up
to any given design FL. Have you looked at the comparative shots PiitP Moose
posted? I suggest that they show a triumph of IS over geometry up to at least
300 mm. I didn't do anything special when I took them, just some shots
wandering around an Asiatic botanic garden.
<Of note Sony does NOT stabilize non system lens that does not report focusing
<distance to cam in x/y planes--thus only 3 axis stabliization. X/Y displacment
<especially imp't for macro. Any idea if Oly has
<5 axis stabilization for lenses on adapters? I have wondered about that for
<ages. Anyone? Speculation welcome.
NEM continues
<<The OM-Ds have CD AF, so it has the capability to know what parts are in
focus. I can imagine a computational system that knows both the actual FL of
the lens, and <<thus the on sensor movement to be expected at infinity focus.
By comparing that to the actual movement, your frequently referenced friend,
geometry, makes it <<possible to calculate a focal distance.
<<What they are actually doing, I have no way of knowing. They say nothing
about IS being limited in any way with adapted lenses.
Hi Moose,
I made no assumption, one way or the other, but curious if Oly pulled off
something Sony was unable or had no desire to do despite touting their platform
for alt lens use.
I would have thought if Oly put some engineering musle to make all 5 axes work
for alt lens macro, they might advertise that fact. Perhaps it really wasn't
much work. I did ping them, but don't know if they will provide a useful
answer. It just doesn't seem like something with which Oly would bother .Oly
does seem to maximise their advantages---they do report focusing distance in
exif where Panny does not ---by using focusing stepper motor data, so they can
get focusng distance easily enough with native lenses at least---kudos to them.
http://wetpixel.com/forums/index.php?showtopic=52938
I did view your comparative images. The IS is indeed very good on the EM-5II
but I have also seen you pull off sharp long FL shots at SS where you had no
business getting such results. I have observed you stabilising the cam etc
leaning agianst a tree etc. I consider you an outlier when it comes to IS
testing, a most excellent one, but an outlier nonetheless.
Only Standardly stable, Mike
--
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