BACK FOCUS ADJUSTMENT
When installing a zoom lens on a camera, sometimes the lens cannot be focused at
either end of the zoom range. If this problem occurs, it may be necessary to adjust the
camera back focus. By adjusting the back focus, the position of the pick-up device in
relation to the rear of the lens is changing.
G
<PROCEDURE>
1. Secure the lens to the camera body, and plug in the auto iris connector.
2. Place a neutral density filter in front of the lens. This will force the lens iris to open to
the max. (In the case of a manual lens, open the lens iris to its maximum.)
3. Set the focus of the lens to full infinity.
4. Set the zoom to Wide.
5. Aim the camera at a high contrast object a distance away and move the back-focus
lever to bring object into focus.
6. Set the zoom to Tele.
7. Repeat the above steps until the focus remains clear throughout the zoom range.
Zoom
Focus
Back-focus lever
8
