Hi Moose,
I don't think this applies to the OM to EF adapters, but I found it in
Pentax to 4/3 and Leica-R to 4/3, so, just a word of advice. These adapters
are made in two parts, one that attaches to a 4/3 body, and another that
provides the thickness and attachment for the specified lens system. My
Pentax to 4/3 adapter came from Fotodiox, a reputable US supplier. The two
parts are held together by pointed setscrews in the outer rim. I made sure
these were tight, but, when used with heavier lenses, I found that they
loosened up. Fearing that I would drop a lens, I marked the two halves,
placed a few drops of Superglue on the mating surfaces, and carefully
realigned and clamped the parts, tightening the rim screws. In 2+ years of
use, it has never showed signs of loosening up again.
My two Leica-R to 4/3 adapters are assembled with Phillips screws in the
face surfaces. I checked to be sure the screws were tight, and have never
had a problem with the two parts attempting to separate. This seems to be a
more secure arrangement, and is the one that I trust to hold the E-1 body to
the Leica Telyt-R 250/4, where the whole assembly weighs about five pounds.
Just my 2 cents.
Jim Nichols
Tullahoma, TN USA
----- Original Message -----
From: "Moose" <olymoose@xxxxxxxxx>
To: "Olympus Camera Discussion" <olympus@xxxxxxxxxxxxxxxxx>
Sent: Wednesday, March 09, 2011 7:02 PM
Subject: Re: [OM] OM to EOS adapter
> On 3/9/2011 11:57 AM, O. H. wrote:
>> ...
>>
>> If you decided to continue reading, I am most probably buying a Canon.
>> I would rather go for Nikon but I assume that there are no adapters
>> for OM to Nikon available. If there are, please let me know!
>
> The simple answer is that adapters that you want to use, i.e. simple and
> without additional lenses in them, are only
> available for 4/3, micro 4/3 and Canon EOS (And perhaps other, more
> recent, mirror less cameras?) (The actual name of
> the lens mount on EOS cameras is 'EF'.)
>
> The reason is that the distance from lens mount to film/sensor of all
> other the mounts is to long to leave room for the
> adapter body between lens and camera body.
>
>> I would appreciate if you could help me with the following questions:
>>
>> 1) Is there any OM to EOS adapter that allows the lens to firmly
>> attach to the adapter? I already bought a very cheap adapter (to test
>> lenses with camera shop's body) and noticed that the lens does not
>> lock into the adapter. So when I am rotating the focus ring, the lens
>> might fall off! I am seeking an adapter that has a locking mechanism
>> with a relief button for the lens. So are there such at all?
>
> As others have pointed out, your experience is not common. Most adapters
> lock properly in both ways, adapter to body and
> lens to adapter. The one you bought is faulty, and should be returned.
>
> Mike and Nathan have pointed out expensive and really expensive models.
> I've been completely happy with the cheap one I
> bought from China.These are really simple, two piece devices, with one
> being the stop down tab screw. There's not a lot
> to go wrong.
>
> Especially as you are just trying this out, I would buy an inexpensive one
> to start with. Rather than the cheapest one,
> from a 25 feedback seller in China Chuck linked to, I'd spend 9¢ more and
> buy from Big-IS, still in China, but with
> excellent feedback on over 20,000 transactions.
>
> I think if you polled the list, you would find the vast majority of those
> who have bought inexpensive ones off the 'Bay
> have found them fine. I can't imagine in what way mine could be better.
>
>> 2) Is there any OM to EOS adapter that would NOT allow focus to
>> infinity? Such a adapter would be thicker and would allow mostly
>> macrophotography (that would be OK with me). Such an adaptor could
>> much easily have good locking mechanism.
>
> Never heard of such a thing. There are at least three reasons:
>
> 1. Not necessary. Even very inexpensive adapters that focus to infinity
> lock properly. If you look at how the locks
> work, it is quite simple to implement.
>
> 2. No one would intentionally buy into such trouble. No matter how you
> warn them, some folks would buy them, then
> complain that they didn't "focus right".
>
> 3. A proper adapter and extension tubes is much more flexible.
>
>> 3) Is there any OM to EOS adapter that would change the aperture as I
>> turn the aperture ring? I mean similarly as in Olympus OM to 4/3
>> adapter. The cheap OM to EOS adapter I bought, I have to manually
>> press the depth of field preview button so that the aperture sets to
>> correct. Well, this is good for focusing, but for macrophotography
>> aspects I would rather have similar action as with OM to 4/3 adapter.
>
> As someone else has pointed out, the way you want it to work is the way
> the vast majority of adapters work. Again, you
> bought a bad model/design.
>
>> 4) Do you find the OM to EOS adapters basically OK for use? With this
>> I mostly mean that are the Canon bodies really good at measuring the
>> exposure?
>
> No, the simple ones can't be relied on for correct exposure with all
> lenses at all apertures. It appears the camera
> needs to know the focal length and/or aperture to correctly interpret the
> light falling on it.
>
> This is true of Oly 4/3 camera bodies, as well. When they first,
> reluctantly, brought out an OM=>4/3 adapter, they only
> approved it for a limited set of OM mount Zuikos. Later, they came out
> with a table showing EV adjustments necessary for
> many others, aperture by aperture.
>
> When I got my first DSLR, a Canon 300D, and a hand machined adapter
> (unlike anything you will see today!), I did some
> simple testing with a 50/1.4 Zuiko. Auto exposure was uneven, tending to
> overexposure as the lens opened up. Manual
> exposure was much better, only slightly brighter at f1.4.
>
> With Sigma 600/8, for a more extreme case, my 5D needs something like two
> stops less exposure than the meter says. For
> slow work like much landscape, macro, etc. it's not a big deal, as one
> shoots. looks at the LCD, adjusts, shoots again .
> . . And for repeated setups, maybe take notes. Remember, test shots later
> deleted have almost no cost at all.
>
> There are adapters with chips that connect to the AF system to confirm
> correct focus. The fancier ones allow you to
> program them using the camera so they report the correct focal length when
> you shoot. I've heard it claimed that they
> make auto exposure more accurate. I don't know myself.
>
>> 5) Once again: are there any adapters (without changing parts of the
>> lens) to fit OM lens to Nikon? I don't really need focus to infinity.
>
> No there aren't, other than the mount replacements Mike referenced. And
> yes you do need infinity focus. Unless you are
> one in many million. You are going to want it sooner, rather than later.
>
> I started with Zuikos on my Canon DSLRs and one basic Canon auto lens for
> casual use. I now I almost never use OM mount
> lenses on it except for specialty uses, like the super teles, the macro
> lenses with tube or bellows, etc. BTW, the
> Tamron 90/2.8 is a really excellent and reasonably priced auto macro lens
> available in EOS mount.
>
> Moose
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