Like the Tamron, the Olympus 40-150mm Zoom ring is located toward the front of the lens. But unlike the Tamron, the Olympus’s zoom ring is much too tight to roll with my outstretched index finger. Function button (L-Fn) mounted on the lens. It makes it possible to adjust functions corresponding to such custom settings on the camera body as “AF stop”. This kind of zoom lens can also be a nice addition to a filmmaker’s bag, especially for nature and animals. The versatility of the focal range combined with the close focussing capabilities and the MC-14 is really interesting for video as well. Unfortunately the lens isn’t optically stabilised so with a Panasonic camera like the GH4, a good video tripod with a nice and fluid head becomes very important to bring home nice sharp footage. When fitted to the OMD EM1, the camera and lens combination is beautifully balanced. It feels just right, not just when carrying it around but when you raise the camera to your eye and shift your left hand from the tripod mount to the zoom ring.

Place both of the telephoto zooms side-by-side and there’s significant physical differences to literally weigh-up. The Leica is noticeably more compact, shorter and lighter. I could squeeze it into my bag standing up whereas the Olympus always had to lay down and occupied much more space. That said, the Olympus enjoys the benefits of internal zooming (less chance of dust or moisture entering the barrel) and a tripod foot for greater stability (which also sports an Arca Swiss dovetail base). Both lenses may feature lens hoods that can fold over the end of the barrel for transportation, but the Leica hood must be reversed and re-mounted, whereas the Olympus hood simply pulls-out. There’s no doubt the Olympus feels more confident and has more physical features (including a programmable function button for Olympus bodies), but again it’s much larger.

Other attributes: The Olympus cameras perform distortion and aberration corrections in JPEGs, and some raw converters do, as well, so it’s getting a little more difficult to talk about such issues for a lens than it used to. If you’re shooting JPEGs, I’d say don’t worry about either. Olympus’ correction doesn’t take out all chromatic aberration in the extreme corners, but it takes out enough that most people would just ignore what does get produced.

Offering long reach with an advanced feature-set and optical design, the M.Zuiko Digital ED 40-150mm f/2.8 PRO from Olympus is a versatile 80-300mm equivalent telephoto zoom for Micro Four Thirds mirrorless cameras. As part of the PRO series of advanced lenses, this zoom distinguishes itself with a bright f/2.8 constant maximum aperture for consistent illumination throughout the zoom range to suit working in a variety of lighting conditions. Its optical design makes use of a series of aspherical and low dispersion glass elements to suppress chromatic and spherical aberrations for notable sharpness and clarity, and a ZERO coating is also used to reduce flare and ghosting for high contrast, color-accurate imaging. I owned Oly MZuiko 12-40 F2.8 Pro and 14-150ii(One with weatherproof). Currently, I use both lenses on the original Em1. However, I would like to upgrade the body since My Em1 is quite aging now with 32k shutter count. I will leave my country for education around 1 year. So I don't want to take the risk of purchasing a camera abroad(out-of-warranty service fee issue) In the comparison with the Lumix lens, I did some basic test shots but I think that images taken in real situations, like the ones you’ll see below, are actually more interesting to share. E-M1, 1/200, f/ 2.8, ISO 1600 – 150mm E-M1, 1/160, f/ 2.8, ISO 1600 E-M1, 1/160, f/ 2.8, ISO 200 In addition, the Olympus M.Zuiko Digital ED 40-150mm lens has a so-called L-Fn button, which allows users to temporarily suspend continuous auto focus when something suddenly comes between the lens and your intended subject. This is mostly useful when shooting a movie clip with C-AF enabled, but the feature can also be used when photographing action.Surprisingly, it didn’t seem to matter what focal length I chose. 40mm, 70mm, 150mm, they were all excellent corner to corner, and right from f/2.8 (no real need to stop down unless you need DOF). And I mean excellent, as in about the best you can obtain from the 16mp E-M1 sensor. If you nail focus, you have acuity. Excellent acuity. Indeed, in the Imatest charts it basically boiled down to this: The lens performed great wide open and didn’t really change much until I started hitting diffraction limits, at which point I could clearly see the diffraction impacts. That’s pretty much as good as it gets in terms of sharpness. It's a really good lens. And there are some nice innovations in it, that make gear heads like me go nuts. Dual element focus (two groups each with linear motors). There seem to be some improvements in autofocus speed but primary a really, really close focus distance. This is great! The only thing to mention is that the 40-150mm makes your kit less discreet. From a distance, it doesn’t look much different from a D7100 with a 70-200mm f/4, especially from the perspective of a non-photographer. But you get less weight and more reach, so there is a benefit if we want to compare it to a medium-sized DSLR kit. I actually wrote a specific article about this topic recently which you can read here. Close focus is a very close 2.3 feet (0.7m), which gives it a reasonable 1:5 maximum magnification. Panasonic body owners need to know that this lens does not have image stabilization; it relies on the camera body to stabilize shots.