Weather-sealed construction guards the lens against dust and moisture for working in harsh environments. From the article I cited above: “Consequently, equivalence theory can be used to help choose an appropriate camera system for a given task. You have to make sure your E-M5 Mark II has the latest firmware, because the 12-100mm PRO lens was released 2 years after the E-M5 Mark II.

on the wide end, so 3 stops ahead in ISO performance, and gives you a stop of IBIS at 1/15s, so it's like having the Oly at 1s exposure.Bolton "I'd rather carry around 200g extra of camera that I like to use versus 200g less of plastic brick that I don't. The f4 lens on the mft gives me less noisy image because the iso is appreciably higher than other images. Isn't criticising an f/4 lens for not being fast enough a bit like criticising a screwdriver for not being a wrench.

You can ALWAYS get the same DOF on larger formats (close aperture), but not the other way round (limited availability of maximum aperture, e. It is very sharp, it doesn't have the chromatic aberations of the Oly except wide open at 14mm, has better contrast and bokeh, no distortion except in wide angle (and still less than the Oly) and goes longer.And your title line "Equivalent to 24mm to 200mm on a full frame sensor yet with constant f4 maximum aperture. So even though I had hankered after the 12-100 when it came out, I just couldn’t justify the overlap and extra cost.