Overall, the autofocus is decent — I just wish this lens had an AF limiter switch and the switch to enter into full manual mode. And of course, the Micro Four Thirds format with the 2x crop factor and the narrower f4 is helping out here immensely.

The lens body is made of metal, everything is tightly assembled, weather sealed and the control rings operate smoothly. Besides the narrower aperture and the lack of “Olympus” on the label, the OM System 40-150mm f4 Pro is missing a few of the design features of the Olympus 40-150mm f2. As the aperture closes, diffraction causes these points of light to spread into starbursts, and it’s another area where one lens may deliver a better result than another. It's going to be a lengthy post / rolling review with a few images and may take a couple of days to add some things that I want to share. All content, design, and layout are Copyright © 1998–2023 Digital Photography Review All Rights Reserved.

When in manual focus mode, the ring has hard stops and minimum and infinity distances, otherwise the lens will rotate freely in either direction while in the AF position. An f4 on Micro Four Thirds isn’t very bright, pushing up the ISO more and delivering less background blur. Balance is near perfect on the E-M1 body, and also on the E-M5 body with at least the half grip installed.

While buttons on the barrel aren’t anything new, the lens has a function button that allows you to control the way you setup the camera’s function buttons. When mounted on a Panasonic or Olympus mirrorless camera, it delivers a 4x range equivalent to 100-400mm, making it ideal for sports, action, distant portraiture and some wildlife too.

But, other lenses like the 12-45mm f4 Pro also don’t have the pull-back feature to enter into manual focus mode.

f/4), an E-M1 owner should be able to go from 14mm to 600mm equivalent in a four lens set that delivers one heck of a lot of performance in reasonably small packages. To be fair, the 70-200mm f/4 variants for DSLRs are very similar in size and weight to the Olympus lens. I managed to shoot this lens at 40mm for a two-second exposure, though I had a much better hit rate with a 1. aperture, you can blur those backgrounds to goo while soaking up enough light to keep those ISO’s low. Corner-to-corner sharpness is also tremendously good, with almost no change in sharpness from center softness at every focal length.When I first saw the close focus distance and lack of a focus limiting switch, I was prepared to be disappointed moving from extremely close to extremely far subjects. It makes sense within the Olympus Micro Four thirds lens range though, as it picks up where the first Pro lens – the M.