In a message dated 2/25/2006 7:14:35 PM Eastern Standard Time, shino@xxxxxxxxx writes: SIMILARLY, i have a 0.7 mutar in bay III for my 2.8F. i could run film thru the thing and develop it to find the answer to the question i am about to ask, but for the fun of it let me ask the fellows: how many stops should you open to compensate for the mutar? thx, -rei Check out http://www.photographical.net/rollei_mutar07.html for one photographer's simple take on the .07 Mutar. He's made an attempt to document his results with comparison pix. All the best, Lance