Olympus OM 35mm film system close-up and macro equipment

Introduction

The PM-SDM-2 Light Excluding Collar was designed for using an OM body on a microscope in conjunction with the PM-BD35A auto bellows of the PMT-35 Photomacrographic System. It had an OM bayonet for connecting to the bellows.

Suitable compound microscopes include the E, F and BH with trinocular heads that have a vertical photo tube with a standard 25 mm outside diameter. The PM-ADF eyepiece adapter needs to be fitted to the vertical tube and an FK or NFK photo eyepiece inserted in the adapter.

The PM-SDM-2 Light Excluding Collar is wide enough to be used with a BH-2 microscope fitted with a trinocular head that incorporates the 38 mm circular dovetail that holds the NFK photo eyepiece.

The microscope has to be positioned on the base of the PMT-35 with the centre of the photo eyepiece directly below the centre of the PM-SDM-2. Then the bellows is lowered until the PM-SDM-2 almost makes contact with the photo eyepiece.

Light Excluding Collar PM-SDM-2

Versions

There was also an earlier two-part Light Shield Tube PM-SDM for connecting an OM body to a microscope in conjunction with the Auto Bellows (or the PM-BD35 manual bellows for the PMT-35) and the Objective Lens Mount PM-MTob.

PM-SDM Light Shield Tube

Sales Information File

Summary

The Light Shield PM-SDM-2 allows the Macrophotographic Equipment PMT-35 to be used for microphotography, preventing false light entering the bellows.

The microscope is put on the Support Stand of the PMT-35, replacing the illuminator base, and the bellows is used as a photomicrographic adapter.

Main Characteristics

It connects to the OM-mount of the bellows of the PMT-35 and slides over the eyepiece.

The eyepiece must be inserted in the proper eyepiece adapter.

Notes – Related Units

For best results in microphotography a photographic eyepiece with low magnification is recommended.

The Olympus FK 2.5× or NFK 2.5× are recommended for 35 mm film.

Be sure to leave some space between the top of the eyepiece and the PM-SDM-2 to prevent vibrations to be transmitted.

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Created 19th May 2026   —   Updated 19th May 2026
Copyright © 2026 Alan Wood