How to do focus calibration for RB67?

Accurate focusing in most medium format SLR cameras is affected by the focus screen, mirror, and flange-back distance. If you’re experiencing a focus issue, it can be difficult to pinpoint the exact cause. Therefore, it’s recommended to have a professional diagnose and adjust the focus. However, if you have a thorough understanding of these components and can identify the source of the focus issue, you can attempt calibration with the focus screen or body mount pins. Method 1: Adjusting the Focus Screen on Top of Camera 1) Remove the focus screen. 2) Mark the original position of each Adjustment Screw (4 screws). 3) Slightly rotate the Adjustment Screws to achieve proper focus. We recommend turning them in small increments (about 45 degree) each time you check focus. You may need a precision tool for this task. Turning 180 degree makes about 0.1mm movement.

• Counterclockwise (Focus Screen Goes Up): Focus will move front to back. (Treatment for front-focused issue)
• Clockwise (Focus Screen Goes Down): Focus will move back to front. (Treatment for back-focused issue)

Method 2: Adjust the Body Mount Pins on the Adapter The adapter allows for minor focus adjustments by modifying the height of the Body Mount Pins (4 screws) used for mounting the camera body. (See instructions linked next for details on adjusting the Body Mount Pin length.[ LINK ] ) If the focus is back-focus, follow the steps below.

1. Turn each of the 4 pins counter-clockwise in small increments (30 ~90 degrees each). It’s important to turn all 4 pins by the same amount.
2. Repeat step 1 with 30 degrees until you achieve the desired focus.
3. Important: Do not turn the pins more than a total of 720 degrees (two complete rotations).

Important: Avoid turning the screws more than a full rotation (360 degrees). If you reach this point and still experience focus issues, it likely stems from other factors on the camera and cannot be resolved with this method. If the focus is front-focus, follow the steps above with clockwise direction.