One of the reasons why so many experienced photographers are drawn to mirrorless cameras is the short distance between the lens mount and the sensor. This smaller distance allows for users to mount many different lenses from a large universe of camera systems to their mirrorless cameras. One of the reasons I bought the Olympus EP2 was the ability to mount my large collections of very good Pen F manual focus lenses to the camera and to be able to continue to use them and benefit from their unique capabilities.
The Sony shares this short flange to sensor attribute and has become a very popular camera/vehicle of using Leica M series lenses, various Zeiss lenses and a raft of Cosina/Voitlander lenses. I recently discovered that several companies make Pen F lens to Sony Nex adapters so I bought one and I've been testing various lenses from the 1970's on the camera.
So far, the 60mm 1.5 and the 40mm 1.4 have come through with flying colors. Or really good colors. Once each of these lenses is stopped down at least one f-stop from their wide open aperture they become competitive with current lenses. Once they are stopped down two or more stops they become premium quality lenses for most applications. I liked working with the lenses on the Pen digital cameras but it was always a process of framing, enlarging the frame for focusing, reducing the frame to shoot. With the Nex 7 I have the focus peaking feature engaged for manual focus lenses so it's really just a matter of focusing and checking to see where the color outline occurs to confirm focus. Bravo. That make things a lot easier.
I decided today to test a lens that I've had mixed results with on the Pen digital cameras. It's the Pen F manual focus, 25mm 2.8 lens. Hitting sharp focus with it on the Pens was always problematic and, at a certain point, I began to suspect that the optic itself was just sub-par. I thought today would give me a make it or break it finality with the easier discretion of the focus peaking.
I've re-evaluated the lens in light of the three photos you see here and from many other samples I took during the course of a hot and sweaty walk this afternoon. When accurately focused the lens can be very sharp. The colors in the lens are more muted than modern lenses and I don't know whether that is a difference in coating or a design philosophy in lens making that's evolved over the years. I do know that I can take a "quieter image" and do quite a bit of manipulation to it before the manipulation becomes obvious. In some ways a flatter and more neutral image rendition gives you more latitude to make changes in post without suffering much. The files don't seem "fragile."
The adapter I got came from Fotodiox and it's much more accurate at infinity that some other adapters I'd gotten for the Olympus digital Pens. That means I can use the depth of field scale on the lens to calculate a hyperfocal distance. In bright light, at f8, I can get a field of focus that's relatively sharp from about 5 feet to infinity when set to the correct hyperfocal distance. That's a real plus for street shooting. With the electronic front shutter curtain of the Nex 7 and using manual exposure control, I can bang out an image with absolutely no lag time whatsoever. And if I've metered correctly (and who couldn't with a camera that "pre-chimps" for you???) and set the correct distance I can shoot without making any adjustments and be sure of a sharp and well exposed frame every single time. Old school meets new tech.
The Pen 25mm does have a few issues when shooting a wide shot with uneven daylight across the frame. I shot a bridge and noticed some color shift to magenta from edge to edge. Other than that the lens is a good, straightforward performer. If you can find one cheap you'll have a nice 35-37mm equivalent focal length for a really high performance camera. That being said, I'm happy with the performance of the kit lens in that range of focal lengths.
Nice day in Austin. Everyone was at Barton Springs pool. Ahhhhh. 68 degree water on a 102 degree day. Perfect.