Olympus OM Equipment for Close-up and Macro Photography

Objective Lens Mount PM-MTob

The Zuiko Macro 20 mm f/3.5 lens and the Zuiko Macro 38 mm f/3.5 lens do not have the normal OM lens bayonet mount. Instead, they have a small screw-thread mount (RMS – Royal Microscopical Society – thread, 0.8″ diameter, 36 t.p.i.), the same as microscope objectives. They require the PM-MTob adapter to enable them to be fitted to the Auto Bellows.

Olympus OM Objective Lens Mount PM-MTob
(front)	(rear)

The PM-MTob can also be used to adapt any standard microscope objective to the Olympus OM bayonet fitting.

This adapter is not intended to be attached direct to a camera body.

Versions

Only one version is known.

Alternatives

At least two companies manufacture adapters that allow the Zuiko Macro 20 mm f/3.5 lens and the Zuiko Macro 38 mm f/3.5 lens to be fitted to a T-mount – this allows them to be fitted to most 35mm SLRs. For more information, contact SRB Film Services in the UK or Beljan Manufacturing in the USA.

Adapter Ring 55→49 mm

This adapter screws into the front of lenses that take 55mm screw-in filters, and provides a 51mm diameter protrusion that fits into the Handy Copy Stand.

Olympus OM Adapter Ring 55→49 mm

The same adapter allows lenses that take 55mm screw-in filters to be connected to the bellows when mounted in reverse on the Auto Bellows.

The adapter does not have a female 49 mm thread, and so it cannot be used as a filter step-down ring.

Versions

Only one version is known.

Alternatives

Ordinary 55–49 mm step-down rings do not have a 51mm diameter protrusion to fit into the Handy Copy Stand. Adding a 49mm screw-in filter mount (obtained by removing the glass from an old filter) to the step-down ring will probably make it suitable.