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[OM] More on the OM->EOS adapter

Subject: [OM] More on the OM->EOS adapter
From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
Date: Thu, 12 Jan 2012 20:54:41 -0500
The story is really too long to tell in its entirety but, just like Dr. 
Flash, I suffer from poor memory.  I picked up the supposedly 
non-fitting OM->EOS adapter with AF confirm chip with the intentions of 
following Moose's advice and checking more closely what was actually 
going on there and whether it could be "fixed".

In the process something got jogged in my memory and this time I tried 
holding the lens release button down firmly while I tried to install the 
lens.  The adapter fully fitted on to all three OM mount lenses that I 
have with me... the Zuiko 24/2.8, Zuiko 50/3.5 and Vivitar S1 90/2.5. 
It was a bit of a struggle getting the thing to slide on and off... it's 
very tight... but it does go on and off.  But do not let go of the lens 
release button or it won't go on.

That's when I recalled the email communications I'd had with Tim Hughes 
on this same adapter and a previous one which was so bad that it 
wouldn't even fit on the camera let alone the lenses.  Here's a quote 
from last July 11
---------------------------------------------------------------------
Good news!  The new adapter arrived today and this fluted adapter, just 
like my much older fluted adapter, fits the Viv S1 90/2.5 macro and the 
Soligor CD 35-70/2.5.  There was one other non-Oly lens that had a fit 
problem on some of my adapters.  Right now I can't remember which one it 
was but really don't care since it wasn't one that was likely to get 
mounted anyhow.  I may even be the old Makina 80-200/4 that I gave to 
some high school kid.

But all is not perfect.  There is one minor glitch in mounting which is 
that the cam that the lens locking pin rides up before falling into the 
lens locking detent is very short and at a 45 degree angle.  The cam on 
Oly camera body mounts is very long with a very shallow rise.  The net 
is that the lens locking pin will not ride up the cam.  You cannot 
completely mount the lens without depressing the release tab on the lens 
until it gets up over the too high, too short cam.  Once it does you 
need to rock the lens back and forth a bit until the pin falls into the 
detent and locks the lens firmly into place.

Before I figured this out I was ready to send the adapter back because 
the lens didn't seem to want to lock into place.  Then I noticed that 
the stop down lever wasn't fully pushed over which meant the lens hadn't 
rotated enough to complete the motion.  After playing with it a bit I 
realized that the problem was with the cam and that depressing the lens 
release lever got the locking pin over the hump.  Slightly irritating 
but not really a problem if you know about it and especially if you have 
adapters for each lens and rarely detach them.  Other goodnesses... the 
adapter actually has OM-EOS etched into the front surface.  The other 
one had no ID at all.

Well, the AF confirm function does work but seems a bit touchy.  You do 
have to hold the focus button down (I've moved mine to the back of the 
camera) then I focused it roughly by eye and then started rocking the 
focus ring back and forth slightly.  I haven't played with it enough to 
be sure but it seem to only recognize focus when the focus ring is being 
turned in one direction but not the other.  I'm not sure which because 
when the focus indicator turned on it was a surprise and I didn't know 
which way I had been turning the ring.  It's just an impression that it 
was always the same (but uncertain) direction.

I haven't tried anything with programming the chip.  Initial fit was 
very snug on body and lens but seems to have loosened up a bit already. 
  Those brass "springs" are probably getting depressed and may need to 
be tightened back up eventually by sticking a small screwdriver blade 
into the spring slot.
----------------------------------------------------------------------

So, I had figured out all of this stuff before and promptly forgot it. 
In my own defense (ha, ha) I was making preparations to go on our trip 
to London/Scotland and the adapter and its problems were totally 
secondary.  But thanks to my email trove I have (sort of) recovered my 
memory.

There's even more to the story (the early part of which involves Moose, 
me and Tim Hughes in a three-way conversation about these adapters.

But to cut to the chase avoid this seller...    :"jiaxichen1985"
His was the adapter that would not fit a single OM mount lens and also 
would not fit on the 5D body.  Totally useless and unresponsive to my 
complaints until I forced a full refund via ebay customer support.

The adapter that I have now that fits very tightly on all lenses (if you 
depress the release button while installing) but does work and, 
according to Tim, has the latest release level AF confirm chip is
<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320655918821&ssPageName=ADME:L:OC:US:1123>
 
from seller "Rainbowimaging"  This seller is located in New York so 
shipping time was very fast for me.

If the progamming and autofocus confirmation works to my satisfaction in 
the field I may buy a couple more of these.

ps:  The testing on the adapter and checking whether the lenses were 
being fully closed down revealed that my 24/2.8 has a slightly sticky 
diaphragm.  When set to f/16 if will not return to f/11 unless one first 
drops to f/8 or larger and then returns to f/11.  Not a problem for me 
since I never shoot the 24mm at f/16.  It could be the problem has been 
there for years and I never noticed it.  Any known problems relative to 
the 24/2.8 that would account for that stickiness coming back down from 
f/16?  Linkage?

Chuck Norcutt



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