Birns & Sawyer (Tewe) Omnitar 200mm f3.2 -- First Look

Sometimes luck just happens and makes you happy.  Yesterday I was thinking about how to convert the Omnitar 200mm f3.2 that I bought the day before, so that I could use it either on Canon or NEX.  The M42 to Canon FD adapter on my desk was staring at me.  Instant brain fart!  I tried it on the Omnitar and what do you know?  The rear of the lens fits the M42 opening on the adpter perfectly.  In fact, it fits so snugly that I don't even need to glue it down to try it out.  I did have to saw off the tail tube, which would scratch the sensor of the NEX-5N if I didn't.  But, even with the tail section off, the rear still hits the mirror on the 1D III, but at least I can use it for the time being on the NEX-5N.

Sharp!  NEX-5N & Birns & Sawyer (Tewe) Omnitar 200mm f3.2 @ f3.2.

The lens now has an M42-FD adapter, and then a FD to NEX adapter.  Since it's not set in place with anything, the lens would rotate slightly if the focusing ring is turned too hard, making it awkward to use.  But that didn't stop me of course!  I walked around my work area at lunch time with camera/Omnitar 200mm 3.2 in hand and had some good walking exercise while taking pictures.

I was hoping the lens would be sharp to the edges, but it was just wishful thinking.  This, and the Omnitar 150mm f3, were made for 16mm movie cameras, and the NEX sensor is quite a bit larger than 16mm film.  This lens has very high resolution at the center and is very sharp wide open, but as I said, the edge is blurry.  Not as bad as the 150mm f3, but not sharp, at least wide open.  Another thing I was hoping for is that it would not vignette, but it does, though I think it's due to the small opening of the lens at the rear.  The vignette is worse at infinity than close focus.  As expected,  there is a lot of purple fringing at wider apertures, a problem with most old lenses.  But how does it render pictures?

Golden butterfly -- NEX-5N & Birns & Sawyer (Tewe) Omnitar 200mm f3.2 @ f3.2

Quite good actually, if you are not using it to shoot landscapes and hoping or razor sharp edges like the Distagon 21mm f2.8.  It does not have the modern lens look of the clinically sharp image, but its personally makes itself seen. Generally, images are pleasing to look at, but I also find it, and its bokeh to be slightly too harsh for a movie lens.  I am not sure I like the bokeh very much, but on the other hand, it's not objectionable.

Bokeh -- NEX-5N & Birns & Sawyer (Tewe) Omnitar 200mm f3.2 @ f3.2

Can't help but to bitch about the lack of built-in viewfinder of the 5N (I know an external one is available, but it's way too expensive).  Today was sunny and it was nearly impossible to see the LCD screen clearly.  The peaking level feature helps tremendously, but for critical focus, I still need to check image via magnified view, especially for longer lenses where depth of field is very shallow.  This makes me think about the Olympus E-M5 with its 5-axis sensor shift IS, coupled with an internal EVF, would probably makes long lenses much easier to use and end up with more keepers.

Wind Chime -- NEX-5N & Birns & Sawyer (Tewe) Omnitar 200mm f3.2 @ f3.2