> 54mm lens giving 1:1 at 22cm doesn't sound right... 50mm zuiko on an
> OM gives 1/2x at 24cm. No cheating and doubling lens focal length just
> because the sensor is smaller.
But why not? This is the one place where it really _does_ make sense to do
that.
In 35mm terms, if I have a 108mm lens that'll focus at 22cm away, and I
focus on a ruler, I'll get ~36mm of the ruler in shot.
In 4/3 terms, if I have a 54mm lens that'll focus at 22cm away, and I focus
on a ruler, I'll get.. eh?.. ~55mm of the ruler in shot.
http://www.opsci.com/index.asp?pagetitle=Calc/ObjectSizeCalc&exten=htm is
the best javascript DOF calculator I've found for this sort of thing.
and now I'm confused -- I can't see where the 1.5 enlargement factor comes
from, I'll admit -- double/half, sure, but one-and-a-half times?
I don't quite see why OM claim their macro is a 1:2 lens, either, if it'll
do more than that. Maybe the closest focus numbers on imaging-resource are
just wrong..
MTF charts and technical diagrams are at
http://www.dpreview.com/articles/olympuse1/page5.asp for whoever was
looking.
-- dan
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