Using a 49-72mm set-up ring as a hood for the Zuiko 18mm f3.5

Photographed with Olympus E-300, MF-1 adapter, OM Zuiko 50mm f3.5 Macro, 1/4sec f11

Olympus Zuiko 18mm f3.5 without hood

Olympus Zuiko 18mm f3.5 with Olympus hood

Olympus Zuiko 18mm f3.5 with 49-->72mm step-up ring

Note: The inside of the 49mm threaded section needed to be bored out to a diameter of 46.5mm (originally it was 45.2mm). The length of the threaded section of the Olympus hood is 1.9mm while the step-up ring was left at its original 2.4mm, which did not reach the bottom of the thread in the lens.

Olympus Zuiko 18mm f3.5 with step-up ring and 72mm filter ring (glass removed).

Although this makes a hood which is overall 2mm deeper than the Olympus hood there is no evidence of vignetting when a thin filter is mounted on top of this combination.