Quote Originally Posted by Renato Tonelli View Post
On what camera do you use it and how do you compose for it (camera viewfinder or separate viewfinder mounted on the camera?)

I have that lens also and as stated 40mm is my favorite "normal". I would love to be able to use it on an M2 without the shoe-mounted viewfinder.
see post #13 of this thread - the M2 35mm frame is small enough to use for 40mm, if the finder is original. If the 40mm is intact it will bring up the 50mm frame so you will need to file the bayonet or use an elastic band on the frame selector.

You can confirm this by flipping the back door of the M2 up.

Some people use the 50mm frame ignoring they get more on the negative.