OM SystemOlympus M.Zuiko Digital ED 40-150mm F4.0 PRO for Micro Four Thirds System Camera Compact Powerful Zoom Weather Sealed Design Fluorine Coating

Sharp, lightweight, compact and decent build quality.Not for a low light or pro work, but very decent lens for a hiking/travel with good lighting conditions.

I have the expensive big brother to this lens, the Olympus 40-150mm f2.8. It's fantastic and sets a high bar for performance and build quality. I also have the cheap but cheerful little brother, the Olympus 40-150 f4-5.6 R and it is the best zoom you can get for ~$100. This lens fits in the middle with a compact design, excellent IQ (close to its big brother), and weather sealing (something the little brother doesn't have). I love the twist action to extend the lens from its travel configuration. From then on its all internal focusing and zooming. Just fantastic. Some reviewers hate the fact that you need to extend the lens to use it, but I think it is genius. I have no problem extending this lens when I start using it. I pair this lens with an E-M5ii and the Oly 12-45mm f4 in a compact travel kit. It's big and little brothers get paired with an OM-1 and E-PL9 respectively.You can't go wrong with this lens. OMDS/Olympus made a winner here that aligns with the compact, light-weight, rugged, and quality ethos of its MFT ecosystem.

I bought it for birds (tele), bugs (tele + 2 ft minimum distance), etc. I have it on an older 16 Mp Olympus EM10-II, which still works well, with its in-body stabilization (IBIS). And you really need that with this lens. Zoomed in to 150 mm (300 mm equivalent), half-pressing the button on the camera is a real eye-opener for the benefits of IBIS. (And newer OMDs are even better, I gather.) Optically, I can't fault it, all the way to the corners, wide open at f/4. And then there's the size and weight (< 1 lb). I could easily carry this all day long on a shoulder strap, no bag needed.Reviews have mentioned the lack of a clutch to switch to manual focus for final adjustment. The lens doesn't offer that. In that situation, I recommend focus bracketing on the camera and take 3-4 shots.Overall: It's not cheap, but it's a stunning extra-usable lens. But you do need IBIS!

A great mid range pro lens. I purchased this over the f2.8 version solely due to the weight. I needed a zoom in this range for long hikes and overnight backpacking trips and this fits the bill. It is much lighter than the panasonic 50-200 (which I also have), smaller as well.I'm combining this with the 12-40 f2.8 lens. Both complement each other perfectly. Both will handle focus stacking on the OM-5 body. I will also use it with the panny 8-18 for a wide range setup.At the current price it was a no-brainer for me. Glad I got it!

Razor sharp and great colors and contrast "out of the box". It's not super light but light enough for my backpack. Worth it to bring back the best images. These Olympus PRO lenses are just a level above the competition.

For my m43 outfit I try to keep things small. I also have full frame, so the m43 stuff has to be compact to make sense. My main m43 telephoto has been the Panasonic 35-100 f/2.8. It's terrific and quite small, but sometimes I want a bit more reach, so I bought the Olympus 40-150 f/4. Both lenses are sharp even wide open. But since I'm not going to carry both at the same time, I have to decide if I want the extra reach of the 40-150 or the extra speed of the 35-100. You can't go wrong with either, and they both seem to work equally well on Olympus cameras. Neither of these lenses is cheap, but as I've said before, with a small sensor like m43, you really can't cut corners with lens quality.The 40-150 f/4 is a "Pro" series lens which means two things. it's water resistant and it's really sharp. Otherwise it's like other Olympus lenses, partially metal and partially plastic. I wouldn't say the zooming is silky smooth, but it does the job. The lens collapses to reduce length when not in use. This works well because there is no locking mechanism--you just turn the ring. Bravo, Olympus! I've had collapsable lenses with lock buttons and they are a two-handed, time wastin' PITA.The included lenshood does have a lock button, but since they got the lens right, I can forgive the hood. (Locking lenshoods make sense if the hood is rectangular; the lock assures proper positioning of the rectangle so it doesn't cut the corners of the image. With a round hood, there is no point). I just have to remember which of my lenshoods need to be unlocked and which don't, so I don't break anything.Summary. Sharpness is very good, focusing speed is very good, image stabilization is very good. Contrast seems a little low, but ok. Focuses really close! Personally, I don't miss having extra buttons on the lens or the manual focus clutch thing. I have lenses with these features and don't use them. Your needs may be different. One interesting bit of trivia; the 40-150 always opens to f/5.6 for starters. You would think it would default to f/4 but apparently not.All in all, a very good lens priced like a very good lens. If you're happy with a less expensive zoom in this focal length range, don't try the 40-150/4 because you'll be spoiled.

Albeit, this is my first Pro lens, the quality is noticeable. Extremely sharp. Medium weight. Really nice build quality.

Nothing to criticize. Compact, turning the focus ring to actuate the lens is NOT an issue. I’ve shot mostly wide open lens, f4, and pics are sharp.