How about the new Heliar 15mm (Cosina) for 360 deg pan ?

[Sofjan@xxxxxxx]

 Hey guys i just got my hand on a 15mm Heliar from Voightlander (cosina) lens 
along with the body. My firrt 5 rolls of film blow my minds away. It is very 
very good lens. Very Contrasty.  But with probably 1/2 to 1 stop light fall 
of at the edge. Very sharp lens too. 
And it i rectilinear. all in a very small package. 

    I'm thinking of mounting it in the 360 deg larscan amera to replace the 
17mm tokina. 
   My consideration is It is a whole lot smaller.  15mm and rectilinear . 

 Now my problem . Since  Heliar is not retrofocus design the rear element 
stick into the camera body. So i cannot mount the lens to the body via rear 
lens cap. 
Question. What thread is the leica screw mount ???  I know it is 39 mm but 
what pitch ?  
 Any easier solution of getting the mounting plate cheap ?  
Machining one out of thick metal is probably not going to be cheap. and i 
don't think extension tube is available for leica screw mount ,Or is it ?? 

   
   Thank you in advance.
Sofjan mustopoh