Having bought the original version of the 7-14mm in June 2005 and now also have the new version, so I thought people might be interested in my views of both of these. The original is a wonderful beast and have used it on my E-M5 and E-M1 bodies via an MMF-3 adaptor, which 'Does what it says' admirably, especially when on the E-M1 body which employs two AF systems, (Contrast or Phase-Detection) so when you attach a 4/3rds lens, the latter AF system is automatically selected. However, the 7-14mm f4.0, with the MMF-3 adaptor, is one hell of a monster, as you will see from the images and statistics below: New 7-14mm f2.8 - 590g, 118mm long x 82mm wide. Old 7-14mm f4.0 - 930g, 145mm long x 90mm wide including the MMF-3 adaptor. If you feel the new f2.8 Olympus lens still just isn't compact enough, there is also the Lumix version, which is 83mm shorter, has a 12mm smaller diameter and is 290g lighter; my comments on that option, I will cover later on. Returning to the Olympus models, below are photos of an E-M1 body with the original 7-14mm f4.0 plus the MMF-3 adaptor, and another with the new 7-14mm f2.8 lens; the difference in their sizes is quite obvious! The 'Old' f4 doesn't snap into focus quite as fast as the new f2.8 version does, but it's not enough to be that noticeable, unless the lighting levels you are in are pretty low. Whilst the old version looks a bit of a handful, if you 'cup' the palm of your left hand under the lens, (as you would with a telephoto lens) rather than hold onto the actual body, it's not as cumbersome in use as you may think. If you are taking interior shots and wish to control the perspective distortion that any lenses this wide are going to deliver, the odds are you are going to be tripod-mounting the camera, so the older versions bulk isn't really going to be much of an issue. The improvements wrought by a decade of lens design, are that there is slightly less image 'smudging' at the edges of the frame, the new coatings are better, so flare is controlled more. Furthermore, the evenness of the exposure between the centre and edge of the image has also been improved. With the old lens this is 1.9 f-stops, whilst on the new version, the difference is 1.5 f-stops. Three other things which I haven't mentioned, are that on the new lens, there is a push-pull ring next to the hood that switches the lens between manual and auto focussing, and on the left-hand side of the lens barrel, there is an L-Fn button that can be assigned to a range of different functions via the body's menu button. The new lens also comes with a snap-on lens-cap, that clips onto the edges of the hood, which is a big improvement on the original's push-fit front lens-cap, which many users improved by just increasing the padding inside the cap. Finally, - because they don't appear very often - if you see the old version for sale at a decent price secondhand, and it's weight and bulk aren't an issue, I'd say definitely go for it, as I can certainly confirm that it's still one hell of a performer, and you'll be hard-pressed to see much of a difference, even when pixel-peeping. You could of course use either of these Olympus lenses on Panasonic Lumix cameras, but so far, (June 2015) only the GX-7 has an in-body stabilisation system, since Panasonic fits this into most of their lenses. The Lumix version is not as weather-proof or built as solidly as the Olympus version, but there is a significant weight and bulk saving to be made from purchasing the Lumix version. Whilst the Olympus is undoubtedly worth the extra expense, on the other side of the coin, the 'plastics' used on the Lumix have a well-proven track record, so your choice is more down to how harsh the environmental conditions are, you will be using these lenses in.