I have a lens which is marked "Turner Reich Anastigmat f6.8 Series II 4x5" lens with a Betax No. 2 shutter and rear lens which is marked "Turner Reich 11 IN" The serial numbers on the front and rear lens match. Is this wide angle lens, convertible, or what? I was planning on using it on a Korona 4x5 and possibly try it on a 5x7. I am just getting stared in LF and truly appreciate your input. Thank you.