Rüdiger wrote: look at the 2.8/300. It has a filter size of 112mm like the a 35mm 2.8/300 and it is no smaller. The lenses should have the size of the Pentax 110 Pocket system, as this has also a factor of 2. So the diameter should be only 56 mm.
The diameter would be 56mm if the Olympus lens were "equivalent to" 300mm on a 35mm camera. This is an actual 300mm lens, equivalent to 600mm.
