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Fitting a Canon EOS body on an Olympus OM auto bellows:

See also: 
    General background
    1x to 18x magnification range
    CCTV lens adapt ion
    Comparison of 3 macro lens setups at 5x magnification

Dedicated EOS-to-OM adapters can be bought, but they are rather expensive - this is partly because they are built to retain infinity focus and hence are incredibly thin. They can be bought from i.e. Cameraquest.

Since retaining infinity focus is not an asset for working with a macro bellows, one may consider building an adapter one self. Below are images of two such adapters.

The first adapter:

It was built from an Olympus rear lens cap and a Canon camera cover. First the two parts were lightly glued together back to back. Then 4 holes were drilled in the perimeter and fitted 4 screws to firmly hold the caps together. Finally a rectangular cut-out was made at the centre of the caps, to allow light from the lens to reach the camera.

While easy and cheap to build this a somewhat flimsy setup, since neither end "locks" to camera or bellows mount.

After having worked on fitting a Swift EOS-T-mount adapter to the rear part of a used and cheap Vivitar 2X converter for Olympus mount, it finally dawned on me how to easily built the adapter. The OM mount on the bellows is detachable and is fitted by a flange with a 52 mm diameter. The flange insert in the Swift adapter is also 52 mm, so it was just a matter of having someone with the right skills and tools make a longer flange that would serve as a connector between the Swift EOS mount part and the actual bellows.

Parts for the second adapter:

In the middle the Swift EOS mount with the T-mount insert to the right. To the left the replacement insert cut out of an aluminium block. I'll need to coat it with some black non-reflecting material to prevent reflections.

It is likely that it would be possible to produce the extended insert by sandwiching two T-mount inserts. Drill a good number of holes through them, recess some larger holes about half way through the one going into the EOS-mount part to accommodate the heads of screws going through the two sandwiched T-mount inserts.

The two inserts:

To the left the original Swift T-mount insert
To the right the new insert fitting directly into the Olympus bellows.

The two mounts:

To the left the Swift EOS mount with the new Olympus bellows fitting inserted.
To the right the original Olympus mounting part of the bellows system.

The mounted mount:

The Swift EOS-mount fitted to the rear of the Olympus auto bellow with the new fitting flange.

The interior and ends of the fitting flange was painted with matte black spray painting to prevent internal reflections. 

Prior to the painting the flange was thoroughly cleaned with sulfo and the outer surface was covered with adhesive tape.

The lens:

And just for the fun of it, the front of the bellows fitted with the Olympus 20 mm f:2.0 bellows lens.



Back to extreme macro photography using Olympus OM 20 mm 2.0 bellows lens



Kjeld Olesen
December 4th, 2005

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