Bokeh -- NEX-5 & Birns & Sawyer Omnitar 150mm f3. Click for larger.
For a relatively fast lens (150mm f3), the Birns & Sawyer Omnitar is actually quite lightweight and small. Being able to cover 35mm full frame, this is pretty amazing. But, I believe it was designed as a 16mm movie lens, as the corners are terrible, even stopped down.
Stopping down to around f5.6. Click to see larger
Even with the coating getting disintegrated and looks fuzzy on the glass, the sharpness and contrast is exceptional in the center. I set out to try the bokeh as I didn't have any picture from it that shows the out of focus background in relatively large aperture. I am quite happy to find that the bokeh is very pleasing.
This picture was taken at f4. Note the round aperture blades and sharpness. Click to see more details.
It does exhibit very strong purple fringing. Totally expected from a lens this old. Stopping down eliminates it though, or use software to get rid of it.
I think this lens will be great for video, as it was meant for. Too bad I don't do video, but I enjoy it for the still pictures. A nice change from the garden variety Japanese lenses.