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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