One of the reasons I purchased the Sony A7s was the ability to mount every single lens I own. My interest was mainly about rangefinder lenses, since they are very small and light, and that makes a very good combination with the small size of the camera.
One of my favorite lenses is the wonderful Nikon 135mm f/2 DC. I tried it on the a7s and the results were stunning. Wide open at f/2 it can produce wonderful video (and stills). My main concern is the size and weight. This lens really cannot balance well on the sony, and even when on a monopod or tripod you have to deal with an awkward combination.
So, while it still remains a favorite option, for those times when I don’t need the fast aperture for narrow DoF, I have employed the Leica Elmar 135mm f/4 lens. It’s two stops slower, but at the same time is very small and light for an 135mm lens. Very easy and comfortable to shoot with handheld or on a tripod/monopod.
I consider it a very good choice for the A7s, and it’s a lens that can be found at a good price (135mm rangefinder lenses are not very popular, so prices are affordable).
Images below were taken with the Leica 135mm.
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