Color rendition is fine to me – maybe a little bit too neutral and without significant character (compared to my Panaleica 25mm/f1. However, should it be desired the MF clutch mechanism is straightforward and effective – a good design. You and Don have gotten some really wonderful images – what’s your take on the usability of the Pen-F? Even corrected the lens has high amounts of vignetting in the corners at 12mm (over one stop wide open, two-thirds of a stop even at f/8).

Focusing is internal, so the length of the lens does not change, but the zoom ring is mechanical and the lens does extend as we zoom in to 40mm. Pairing with a dustproof, splashproof, and freezeproof camera body makes it possible to continue shooting in punishing environments such as rain, snow, and dusty environments with peace of mind. The only other control is the L-Fn button, by default set to halt AF, but programmable via the camera menu to a wide variety of alternative functions. Off center performance is good enough that I’m not at all reluctant to put subjects well off center. The 14-42mm lens produces sharp photos, however it's much worse at CA and vignetting compared to the new Olympus 12-40mm.Presumably, standing for "Lens Function", the L-Fn button can be configured using compatible Olympus cameras to set various options -- and options not even related to the lens itself. It probably would be helpful if Olympus figured out some way to put a “check lens focus ring” indicator up on the display when the autofocus system gets grayed out that.

The manual focus is a joy with the Olympus push-pull manual focus clutch mechanism and the build quality is fantastic. Zooming is smooth, but my copy does emit a strange faint rubbery squeaking sound when the camera (E-M5) is turned on.On the other hand it can be of advantage if you wear the cam by strap on your shoulder, because by pointing down to the ground, it’s kept safely aligned to your body. For sure there is no more stealth factor, as the lens is pretty big, and there are no lens markings for hyperfocal focusing or zone focusing, but there are a few advantages. Vignetting on the Olympus 12-40mm lens is very well controlled throughout the entire aperture range and at all focal lengths.