The focal length magnification factor of a cropped sensor – relative to the 35mm format which is the reference size – delivers a ‘virtual’ telephoto effect thanks to a narrower effective field of view. The increased ‘magnification’ – actually the enlargement of the smaller image – is promoted as advantageous for various areas of photography including sports, action, adventure and wildlife, but build a good close-focusing lens and it has plenty of pluses for macros too.
The Micro Four Thirds format – with its 1.97x focal length multiplier factor – delivers the most telephoto bang-for-your-buck in the mirrorless camera world and it’s something that OM Digital Solutions has been exploiting with lenses such as the OM System M.Zuiko Digital ED 40-150mm f/4.0 PRO, which is significantly smaller and lighter than a comparable full-frame lens with a focal range of 80-300mm. Likewise with earlier Olympus models such as the M.Zuiko Digital ED 100-400mm f/5.0-6.3 IS (equivalent to 200-800mm), but still compact enough to be comfortably used handheld.
The OM System M.Zuiko Digital ED 90mm f/3.5 Macro IS PRO is equivalent to 180mm in focal length, so you’re getting in a lot closer to start with, but the minimum focusing distance of 22.4cm gives
