1. Problem: if you purchase an already-converted Vario-Sonnar 24-85 on the second-hand market, beware of lenses which have been previously tampered with or serviced by unauthorized personnel. The top mistake committed is the alignment of the rectangular hole of the rear black plastic shroud. The left is INCORRECT. The right shows how the rectangular hole is supposed to be properly aligned.
    incorrect and correct alignment of rectangular hole
  2. Tools and materials required:
    • foreceps
    • jeweller's Philips screwdriver or better yet, #00 and #0 philips screw driver, JIS Type S (see this)
  3. Procedure
    1. Remove the three black screws holding the rear black plastic shroud using a Philips screwdriver.
    2. Pull up the rear black shroud. The stop screw of the lens mount will get in your way, but you may get around by rotating the rear black plastic shroud clockwise and then lifting it.
    3. You should see three tiny copper spacer rings. It may be still on the lens or stuck to the black plastic shroud you just removed. Make sure you do not drop any of these inside the lens. If you suspect some part has dropped into the inside of the lens, please send the lens back to us for service.
    4. Put one of the black screws back to plug the first small screw hole counting from the 8 o'clock position. Put the two of the brass washers supplied on the second and the fourth small screw hole. The rest of the screw holes are not used. The screw and the brass washers will raise the 24-85 rear shroud just enough that the back of the lens is completely flush. One brass spacer remains unused. Click on image to enlarge.
      brass washer on black spacer
    5. Put the rear black shroud back, getting around the stop screw of the lens mount. Rotate counter-clockwise but do not shovel the copper spacers into the lens while doing so! Rotate until the rectangular opening aligns correctly as shown in the picture below.
    6. Secure the rear black shroud using the remaining 2 black screws. The 2 black screws shall go through both the screw holes of the rear shroud and the 2 copper spacers.
      put EF mount on (VS24-85)