Originally posted by boriscleto No.
That kind of approach is more or less what i used for the Altix conversion.
IIRC, with Exakta/Exa lenses infinity should be adjusted a little. With the Altix mount the register comes out perfect, with no need for shimming/sanding/adjusting.
Exakta lenses with the side button are different beasts, the button (and the back of the lens where it is hinged) must be removed. So the back part of the lens has to be rebuilt.
The mechanism that set the diaphragm to either auto or manual should also be removed. With the first conversion the diaphragm could be operated only with the front ring set to manual. After the conversion has been redone i didn't even attempt to move the ring (it's at the front, close to the hood). It works the way it is, and i'm not going to mess with anything!
EDIT:
My advice to all those who crave for a Trioplan 100mm is one: be patient!
Asked prices are quite crazy these days, and the only way to avoid rip-off's is to use common sense and wait for the right chance (Ebay Germany is where you should look for it).
DIY is a good way to save on the cost of an expensive conversion. M42 versions are definitely more expensive, but if you have to pay for the conversion from Exakta mount, it could even become more expensive.
I could pay around 200 euros cause i bought it "as is", practically blind eyes, and from the blurry pictures it was evident that the lens had some serious problems:
1) the glasses had fungus/haze
2) the barrel was in very bad repair (the rear was apparently damaged and dangling from the rest of the lens, connected by a single screw!)
3) it was the late "N" version (black), with less diaphragm leaves and in Exakta mount with the obnoxious side button
The gamble paid off, but it was a risky one.
Now the lens looks quite nice, much better than the way it looks in the pics i posted.
The photos were taken with another of my favorites, the Sigma Apo Macro 5.6/180mm (manual focus). The sharpness of the Sigma and the use of fill-in flash evidence any little aesthetic problem in a lens that probably has seen a lot of use and, let's not forget, was made in the first half of the sixties