EDM InstrumentsTo Contents PagePrevious instrument

  Surveying Instrument Collection 


OMNI Optical Products Inc., USA


OMNI Tiltable Prism

Serial Number



265 x 155 x 140 mm (prism)




This tiltable (round) prism in a plastic housing is attached to a plastic (orange/white) target plate, that is equipped with a gun sight on top. The prism can be screwed into the target plate from two sides, providing 'zero (prism) offset' and '30 mm (prism) offset' options.

The clear aperture of the prism is about 58 mm in diameter. The front surface of the prism is about 45 mm from the vertical and horizontal axes of the target (for the '30 mm offset' mounting option).

There is a friction coupling for the tilting of the prism/target in the vertical plane. The rotation about the vertical axis can be locked by a locking screw in the carrier.

The prism/target assembly has a 5/8 inch female thread. In the set at hand, it is mounted using two cylindrical adapters on a tribrach adapter plate with a ZEISS (DIN) cylindrical forced centring bore of 34 mm diameter. The carrier is possibly a SOKKISHA MA01 simple carrier ('DIN/Geodimeter'). The vertical play of the spigot in the tribrach adapter is 1 mm (which makes the equipment unsuitable for precision measurements).

Here, the tribrach adapter is inserted onto a SOKKISHA WOA (Wild-type) tribrach (No. 418) with optical plummet. The height of the reflector is about 193 mm above the bottom base of the tribrach (at midpoint setting of levelling screws).

History & comments



no bag, no box


Prism assembly very good, paint damage on carrier and tribrach


Donated by Bill Rein, Surveyor, Balgowlah NSW, April 2012


Catalogued by J. M. Rüeger on 15.5.2015. Photos by J. M. Rüeger.

[ Back to Contents ]