Olympus is famous for the quality of their lenses. In the OM line, the 90mm Auto-Macro f/2 and the Auto-T 100mm f/2 lenses were quite famous for their quality. The same could be said for the likes of the 24mm f/2.8 and the 35mm f/2.
The OM Auto-Macro 50mm f/2 is lesser known. And that’s unfortunate. It’s a fairly late 1985 design with floating element design and a crazy 9 elements in 7 groups–very complex for a double gauss 50mm lens, especially one that was designed 30 years ago (incidentally, my copy is from 1996, at little newer).
But it’s complexity gives a few advantages. For one, it has a perfectly flat field. There’s basically no field curvature at all. On top of that, it is incredibly sharp. It’s one of the sharpest normal lenses I’ve ever used–competitive with the Contax Zeiss 45mm f/2. And it has the strength of being extremely sharp across its entire focusing range, which means its an able-bodied lens for normal shooting and also close-up work.
Vignetting exists at f/2, but disappears at f/2.8 and it doesn’t flare very much at all. All in all, a high quality lens that I would highly recommend. I love it on my Sony A7, but I also use it with a Metabones Speedbooster on my Olympus OM-D E-M5 for an awesome 35mm f/1.4
It’s a bit pricey for legacy glass–$300 should be expected, less than that is a steal–but there are few MF lenses that can compete with it in terms of its balance of resolution, aperture size, and close-focusing ability. A 25mm extension tube will give it true 1:1 macro ability too. I use that combination for slide copying with my A7.
All of these photos were taken with the lens…sorry about all the gear shots–I really like my E-M5 & 75mm f/1.8. More photos with the Olympus OM Auto-Macro 50mm f/2 can be found in my Flickr Album for the Lens: Auto-Macro 50mm f/2