Ah, the Contax T. Made by Kyocera with a Zeiss-branded Sonnar-design lens, it sits here, glistening in the sunset, made of equal parts optic bliss, titanium and pure awesomeness. It can command surprisingly high prices on the used market and certainly it is worth preserving as a part of camera history.
Oh, who am I kidding, we're gonna tear this here unicorn apart.
Another view of the carnage. The sound you hear is the cry of a thousand Contax collectors.
The objective? The objective! Pun intended. You see, the Sonnar 38/2.8 is renowned as a good lens, and also, it is extremely small for a full-frame capable lens. The design cannot be adapted to an SLR, as the Sonnar is a rangefinder design that sits too close to the sensor. However, on a NEX it should prove perfect. And it is certainly crazy small, while still being cheaper than many alternatives. I paid SEK950 for the camera, as of this writing 110 or $135. By the way, I decided on this lens because the similar Minox lens is a simpler Tessar type with oddly-shaped aperture, and the similar Rollei 35 lens sits on a camera that is more expensive in its Sonnar versions (the cheaper models having simpler triplet and Tessar designs). This "Sonnar" is a simpler design than many classic Sonnars, though, being a five-element four-group design.
This is how the lens looks from behind with all unneeded items removed. I have also used a spring from the camera to keep the central shutter wide open at all times, it is the one below the wires. Also note the mounting ears -- two of them are going to be used to secure the lens in the cap, the two where spacers are mounted are used for the anti-reflection shroud... or whatever it's called.
In my last shipment from well-known reseller of questionable stuff DealExtreme I included several of this cap set to actually make adapters and the like. They are perhaps a little expensive, but much cheaper than Sony originals, and they are made of good quality plastic. I used my trusty Dremel 8000 to make a circular hole big enough for the lens to fit through, and then drilled two small holes to use screws from the camera to secure the lens from the front.
Also, I found a part in the camera that I could use to make a locking hole -- the normal cap will just twist off, as caps do. Unfortunately I didn't manage to photograph that part before hot-glueing it in. It needed a little bending action to fit. Also, you'll have to press the lock button while mounting the lens, but no big deal.
The anti-reflex shroud is securely mounted again, using two of the holes and spacers. It has to be cut somewhat to fit.
The result looks like this. It will focus slightly beyond infinity, as position relative to the focal plane isn't perfect in the cap. This also means that the minimum focus distance changes; from a stated 1 meter to slightly over that, around 1.1m. I won't bother with fixing that, as the alternative position in front of the cap loses infinity focus; the third alternative, making a large hole in the cap using a thin metal sheet in front for mounting, requires way too much engineering for me.
This is my Warhol impression of the NEX-5 with mounted lens.
And this is a top view showing the NEX with mounted result besides the kit lens, positioned flange-to-mount for a size/length comparison. The kit lens is shown without its hood, which generally is needed and makes it even longer. Sonnar designs on the other hand are naturally flare-resistant. Do also note that this is a full frame lens! Why Sony doesn't make an autofocusing pancake lens with these specifications (or slightly faster) the world will never know.
Of course you wonder how the lens performs on the NEX. Go to part II for the results.
And if you liked this, you'll love when I took a 100 year old Kodak lens and my a900 to New York.