Conclusion

As a smaller, lighter, simpler and cheaper alternative to the flagship M.Zuiko Digital ED 40–150mm F2.8 Pro zoom, the new F4 version makes perfect sense for a lot of enthusiasts. Sure, it might not be the most exciting lens that Olympus have ever made, but it's a big step-up from the usual variable aperture zooms in terms of overall quality.

The OM System M.Zuiko Digital ED 40-150mm F4.0 Pro proved to be a great partner to the equally new OM System OM-1 camera, forming a compact, well-built, weather-proof system that delivers excellent image quality. It would be even better suited to the smaller E-M5 Mark III camera, weighing in at less than 800g for the complete package.

Optically, both the centre and edge sharpness are very high throughout all of its focal length range, even at 150mm. Sure, you don't get the faster maximum aperture of f/2.8 offered by the M.Zuiko Digital 40-150mm f/2.8 Pro and therefore quite the same creamy bokeh effects, but on this lens you don't have stop down at all at any focal length to get pleasingly sharp results across the frame.

Chromatic aberrations are almost completely absent, vignetting is not a real issue, and distortion is very well auto-corrected through software algorithms. The only notable optical issue is significant flare when shooting directly into the sun.

The lack of in-lens image stabilisation makes it somewhat impractical for owners of Panasonic cameras which don't have IBIS built into the body, but Olympus owners obviously benefit from the superlative in-camera image stabilisation that most of their MFT bodies provide, of course including the new OM-1.

Overall, it might not have all the bells and whistles offered by the faster f/2.8 lens, but there's a lot to like about this new f/4 variant. It comes highly recommended to anyone who wants a versatile telephoto zoom that won't break either your back or your bank account.

Ratings (out of 5)
Design	4.5
Features	4
Ease-of-use	4.5
Image quality	4.5
Value for money	4.5