Hello,
I purchased on eBay an Olympus Zuiko Auto-S 50mm F1.8 lens (the lens is marked
"Made in Japan"), Serial No. 5870379. Although used, the lens appears to be in
near-mint condition.
I also purchased an adapter to fit this lens onto a new Panasonic DMC GF1 micro
4/3 camera body. I take pictures through a research microscope, through a
telescope, and just for fun. In the first 2 of these cases, focus is critical.
One of the main reasons for selecting this camera is the live on-screen
enlargement capability (which is super) as a focusing aid. The adapter I have
works ok as far as coupling the lens to the camera. There is, of course,
neither "auto" nor electrical connection.
Here's the problem, with the OM lens mounted on the adapter (or just holding
the lens in my hand) the iris opens and closes smoothly, but only when holding
the rectangular button on the side of the lens. Inside the lens is a
spring-loaded articulator that are clearly designed for automatic control of
the iris. If I hold this at its limit, it has the same effect as holding the
rectangular side button, i.e. the iris opens and closes smoothly as the f-stop
is changed. Left to its own devices, the lens stays wide open.
Bottom line: I don't know if I have a lens that isn't working the way it should
or if there's some function of the lens that I just don't know about or if I
have an adapter that doesn't do what it should.
It is clear that lots of folks use adapters to connect any number of lenses
(including the Olympus OM Series) to any number of cameras. I have fair
experience with Pentax, Sigma & Vivitar lenses, with adapters to paste them
onto bayonet or screw mount cameras, and with adapters to paste cameras to
telescopes and to microscopes, bellows & extension tubes. With the lenses I'm
familiar with, you turn the diaphragm ring and the iris opens and closes---end
of discussion. But I'm not familiar with this, my first Olympus lens, so a bad
lens is a possibility. Is what I have described in paragraph # 3 above, the
normal operating scheme for the OM Series lenses?
I have a problem here and I'm hoping someone can make some helpful suggestions.
My problem seems to point to the adapter. I need a good Olympus OM lens to
micro 4/3 mount adapter and I don't think I should have to pay $150 to $250 for
it. Can someone suggest a brand of adapter that works the way it should with OM
Series lenses.
Thanks in advance for your help,
Richard
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