The front element does not extend nor does it rotate during focusing (and zooming), making accessories such as circular polarizers easy to use with this lens. Stopping down to ƒ/4 to ƒ/5.6, you have the "sweet spot" of apertures for critical sharpness at all focal lengths. Corner to corner, the lens displays fantastically sharp images in this range of apertures. We did see some diffraction softness come into play at the smaller apertures such as ƒ/16-ƒ/22, but overall it wasn't very severe. I have very little experience with macro but my camera club challenge for this month is macro so I decided to give it a try. Since I haven't done it hardly at all I haven't invested in a macro lens but I remember reading here that the 12-40 can be used for macro so that was my plan.

Unfortunately for smaller sensors, easy-to-get lens resolution in lp/mm is largely independent of lens format. My 28-200mm (which is surprisingly sharp, although it has other optical issues) is delivering about 20MP of scene resolution on FF, which means about 8.5MP on APS-C. However, A FF sensor is nearly 4X the area of an MFT sensor, so my 28-200mm would only project about 5MP of resolution on an MFT sensor. Excellent MFT lenses tend to come in at around 6-7MP; only one that DxO tested reached 16MP (on a 20MP sensor).In my case, going either way would make other lenses in my collection obsolete, the 12-40 would replace my old 12-60, already a stellar performer but the adapter and slower contrast detect AF are annoying. On the other hand, the 12-100 would completely crush my 14-150 II, a practical lens but one I never was quite pleased with the IQ ("kit zoom IQ"). While it is a larger lens for Micro 4/3 in comparison to some of the tiny primes, it is not oversized and much smaller than something like the Canon 24-70mm f/2.8. You can carry it attached to your camera all day and not notice the weight. First, stabilization. If you’re shooting on a Panasonic body, the Panasonic lens probably gets the nod simply because it has OIS and the Olympus does not. The 12-100 is a compromise. A great lens, by all accounts, but still a compromise. You already state very clearly that you find this lens slow. I think you might find it a compromise too far. Many of the posters state that they use the 12-100 more than the 12-40 when they own both. I would totally expect this. Much more of my shooting is in good light than indoors or in poor light. Another problem with clipped color. Again you might be able to recover this somewhat in post if you shot RAW, but hard to see what else is there because of the blown channel. Part of the problem here might have been the time of day. It looks like parts of the flower are overexposed while other parts are underexposed. Harsh shadows from Noon-ish sun? For this type of shot you either want an overcast day or you want to shoot when it is either evenly lit by sun or in full shadow (using a flash perhaps).

In terms of the optical construction, the new Olympus 12-40mm ƒ/2.8 Zuiko PRO is comprised of 14 elements in 9 groups, with two EF elements, 1 EDA lens, 2 HR lenses, 1 HD lens, 1 DSA lens and 2 aspherical lenses. It has a 7-bladed circular aperture that stops down to ƒ/22.The OM System 12-40mm f2.8 Pro II doesn’t contain a whole lot of innovation over the previous lens. It has better optics, fast autofocus, and a whole lot of things the previous version had. But in the grand scheme of things, there’s not a lot that’s groundbreaking here. Comparatively speaking, it doesn’t shine as much compared to many of the other PRO-monikered lenses from OM System. Ergonomics With a FF camera, as @NZ Scott says, you can just up the ISO 2 stops and still come out with a very good image and equal or better noise. When you're holding the camera up to your eye, with the lens cradled in your left hand, the balance with either is good, though the 12-35/2.8 feels slightly better as it is less front heavy. I think this is what most people talk about when they about balance.

EDUCATION: Chris graduated Magna Cum Laude from Adelphi University with a degree in Communications in Journalism in 2009. Since then, he's learned and adapted to various things in the fields of social media, SEO, app development, e-commerce development, HTML, etc. Perhaps the closest alternative to the Olympus is Panasonic's 12-35mm ƒ/2.8 lens. With it you get a similar, albeit slightly shorter focal length range and a constant ƒ/2.8 aperture. It also features built-in optical image stabilization, which might be a moot point for Olympus users as most of the company's cameras feature sensor shift IS. It's also a very sharp lens at all focal lengths and does well at controlling CA, but it shows more distortion and more vignetting than the Olympus -- and it's more expensive.The Olympus M.ZUIKO Digital 12-40mm f/2.8 Pro lens attached to an Olympus OM-D E-M1, extended to 40mm Conclusion E-M1, 1/640, f/8, ISO 200 – M.Zuiko 12-40mm at 40mm GX8, 1/1250, f/8, ISO 200 – Lumix 12-35mm at 30mm Meike 6.5mm f2 Fisheye: an interesting combination of fast aperture and very wide fisheye lens, but we haven’t tested it. There is also an 8mm f3.5 but it is designed for DSLRs, and is therefore larger.