The m.Zuiko 12-100mm f/4 PRO
Disclosure: I am an Olympus Visionary and as such, receive compensation from Olympus America. However, no compensation was paid for this review. I endorse their products because I truly believe in the quality of their gear.
No matter how many lenses you own, chances are that you have one or two that you end up reaching for more than the others in your bag. As a long time Olympus shooter I own most of the micro 4/3 lenses on the market today, and I use many of them quite regularly depending on the situation. That being said, I am finding that the new m.Zuiko 12-100mm f/4 PRO is spending a lot more time attached to my camera than any other lens. It has become my workhorse lens, for a number of important reasons.
The 12-100mm is a constant aperture f/4 lens that measures 116.5mm long by 77.5mm in diameter with a 72mm filter thread. Like all Olympus PRO lenses it has a programmable lens function button, a manual focus clutch and is weather-sealed, meaning it is splash proof, dust proof, and freeze proof. It has 17 elements in 11 groups with high quality construction and the Z nano coating to reduce glare. Perhaps most impressive is the 5-axis Sync image stabilization that works in tandem with the in-body image stabilization of the OM-D E-M1 Mark II to produce up to 6.5 stops of IS.