OM SYSTEM OLYMPUS M.Zuiko Digital ED 12-40mm F2.8 Pro Lens, for Micro Four Thirds Cameras

I've owned Olympus' OM-D E-M5 camera body since Christmas 2012. Using the kit 12-50mm and the 40-150mm (24-100mm and 80-300mm 35mm equivalent) lenses I've had a fun year capturing photos. The camera has been everything I wanted it to be, with the exception of being just average tracking kids playing soccer.But the 12-40mm f/2.8 lens takes the camera to a different level. I thought I was getting decent performance from the 12-50mm lens -- and I thought wrong. It's okay, for what it is, but it's slow (f/6.3 at 50mm) and just average in sharpness. With nothing to compare to, I didn't realize how it was holding back the E-M5's potential.The 12-40 is truly top caliber. Sharp from corner to corner. Chromatic aberration cannot be found. Fast for extending the E-M5's low light capabilities at modest ISOs (I can gain nearly three stops from the 12-50mm in many situations). On the PC I'll zoom in on shots and be astonished by the crispness that simply didn't exist before.Having never owned an expensive DSLR (I had a decent Nikon FE2 film body and some Vivitar Series I lenses in the 80's, however), I'd been lulled into thinking the images I was capturing were simply all that such a camera was capable of. The E-M5 is a very good micro four thirds body, after only the new E-M1. What difference could one lens make? Well, as it turns out, a great deal.The 12-50mm has a smooth motor drive mode for video (which I rarely shoot) and a dedicated macro mode, which is nice. But the 12-40mm, while not being optimized for macro, turns out to be a fully capable macro lens as well, better than the 12-50, IMHO, because of its superior resolution and significantly faster performance and ability to isolate at f/2.8. The only step up for close up photography being to a dedicated macro lens. (And yes, I know that with regards to depth of field it is twice that of a full frame sensor. But f-stop is dimensionless, and with regards to light-gathering-per-sensor-size/exposure/ISO, f/2.8 is f/2.8 is f/2.8, whether it be APS, M43, full frame or a large format camera.)The only thing I don't like is the price. $1,000 was a big chunk. But the way it has changed the performance of the E-M5 is truly revelatory. There really is a significant optical difference between a decent mainstream consumer lens and a pro level lens. The 12-40 lives on my camera now, and the 12-50 is going to end up on eBay.If you've got the E-M5 or M1 and can afford it, this lens is a no brainer and will not dissappoint. Since the long end is only 80mm equivalent, I think even Lumix body owners can enjoy it's benefits despite not having the in-camera stabilization that Olympus bodies have.

Honestly, what can I say about this lens that hasn't been already said? This lens has become for many reviewers and bloggers, either the Lens of the year or runner up. This lens has pro level IQ, amazingly fast AF and one of the most useful all around focal range for photography today. at 2x crop factor on m4/3 it behaves like a 24-80mm. It has nice bokeh and the ability to for decent subject isolation (shallow Depth-of-field) at 35mm+ (70mm) and very sharp at 12mm (24mm) wide angle. Some sites have said that the 12mm f2 lens is slightly sharper but to me it's negligible. PLUS you get all this IQ and focal range in a weatherproof package! Pair that up with the OM-D EM-1 and you have an adventure waiting to happen!Another question that pops up frequently on blog pages and review sites is the question between this and the high quality prime lenses out there for the m4/3 format. My opinion (just my 2 cents) is if you plan on shooting on nice bright days and don't want the hassle of changing lenses, then bottom line, this is your lens. On sunny/bright days you will end up stopping down the prime lenses anyway so you will get just the same amazing results especially if you pair this with an Olympus OM-D that adds in-body 5-point IS and Chromatic fixes in the software for this specific lens.On the other hand, if you like to shoot in low light, have no problem switching lenses, and generally want the ability for a very shallow DOF (depth of field) and subject isolation you can get on the m/43 format, stick with primes. Though to be fair, the bokeh is perfectly fine for my taste on this lens.One detail that is often overlooked with this lens is it has an amazingly short focusing distance. This means you can get pretty darn close to your subject which is like having a sudo-macro function for this lens. This just adds to the incredible diversity of this lens.If you are concerned with price, you shouldn't be. A lens of this quality at this price is an amazing deal. Here is my cost comparison/value break down:If you bought the 12mm F2 and 45mm F1.8 you would be $200 above the cost of this lens (all brand new) and only have 2 focal lengths.The equivalent price in primes would be the 17mm f1.8 and the 45mm f1.8 but you lose the nice wide angle 12mm focal length and gain possibly the "best portrait lens" for m4/3 cameras with nice creamy bokeh and sharp IQ.To me the ideal prime set is the 12mm f2, 25mm f1.4 (Panasonic) and 45mm f1.8 which puts you at roughly $1800 give or take.A nice f2.8 combo would be this lens (12-40mm f2.8 Pro) and the 60mm f2.8 macro giving you a fully capable system of varied focal lengths plus macro and medium telephoto capabilities all for about $1400.Pros:Extremely Sharp IQ corner to cornerSuper-fast AF (I think faster then my L series lens tbh)The best and most versatile focal lengths for everyday photographyAbility to get very close to subjects. Just a few inches in factLarge Aperture for decent bokeh and good subject isolation at the higher focal lengthsWeather-proof!All metal constructionMF 'choke' design for quick switching to Manual Focus modeIncludes a customizable L-FN button on lens for additional functionality.Cons:Big and somewhat heavy (though half the size of lets say the Canon 24-70mm f.28 L) - The size doesn't bother me in the least I have to add. Makes the E-M1 look pretty awesome.Tube Extends during Zooming (would have liked the elements to stay within the lens, thought this would probably double the price)Not the smoothest zoom and focus ring on the market. The other primes I have are way smoother. In fact there is small 'tap-like vibrations' when zooming. After speaking with Olympus directly they informed me this is normal operation.Loses almost 2 stops compared to the primes available today for m4/3 format cameras.I'm happy to answer questions posted here in Amazon. Good luck!