Olympus M.Zuiko Digital ED 12-40mm f/2.8 PRO

Solid build quality, great glass. I purchased this lens to go with the Panasonic GH4, I chose this lens over the Panasonic Lumix G X Vario 12-35mm f/2.8. The reason for that is build quality. The Olympus lens is all around metal and feels really well built. As where the Lumix seemed a bit on the rubber-plastic side such as on the focus ring and the lens itself. The Olympus lens doesn't have O.I.S. but I rather stabilize if necessary in Premiere Pro, and with the 4K image on the GH4 you can stabilize so well and have plenty of room to re-frame if it comes to that. The lens' image is great in my opinion, great lens to begin the MFT glass collection with, giving you a focal length of about 24-80mm with 2x crop, a little more in 4K = 2.3x. It has given me great video and photos as well. It has a virtually unnoticeable flicker when zooming in as opposed to the Lumix where it was noticeable, it all depends on what kind of work you do with your camera to know if that would be an issue for you. Autofocus has worked well 98% of the time though I tend to use manual focusing most of the time. The other great feature is the focus ring, it can snap back to give you definite focus points giving you complete control on focusing when using a follow focus or fixed focal lengths, or you can snap it to endless turning and use to fine tune together with autofocus or whatever your method is. I like the size and weight it gives the camera when mounted, the lens cap has center pressure levers allowing for easy on and off of the cap, even with sun hood on. Anyhow, I think it is a great lens for the price and overall great glass. You will not be disappointed.Read full review

Impressive but noticeably heavier This is an impressive lens that feels so solid and precision that it makes you want to go out and use it. There is a trade off, and that is size and weight. For me the size is not really a problem since I had been using the Oly 14-42mm f3.5-5.6 kit lens from my old 4/3 camera with an adapter on my EM1, so this 12-40 is basically the same size but with a larger diameter lens (62mm v. 58mm). The weight difference is noticeable however. I like the extra bit of wide angle range and the wider, constant aperture. I have only shot some test images, but so far they look very good. The zoom and focus rings feel totally solid. I like the manual focus clutch too.

Sharp heavyweight As advertised a quality set of optics. No complaint. Except two things: One I have it mounted on the smallish Olympus Pen F and my right hand firmly around the camera because of the weight causes me to inadvertently brush some of the buttons on the super menu with results I don't want. Also, if one leaves the MF ring in that position and turns on the power, you may take out of focus shots because the AF is turned off. Need to get used to these issues. I wish it were a bit lighter-suffer from arthritis in the thumbs!