Adjusting the Flange Back Distance
Linglung series lenses will all go through flange back adjustment based on M4/3 standard before shipping,but flange back distance can vary on different cameras. If the flange back distance is incorrect, the camera will not focus at the correct distance.linglung series hasfast adjustment structure which is placed between aperture ring and lens mount.
To correct the flange back distance,please follow the steps below.
1.Ready your object. You can use a "Siemens Star",a pattern of black-and-white radiating spokes available on the www.dzofilm.com website. Download and print it.
2. Attach the lens to the camera.
3.Stop the aperture at T2.9.
4.Zoom out to 24mm or 70mm
5.Rotate the focus ring to focus on the Siemens star. Find the position at which the black-and-white spokes are the sharpest.
6.Zoom in to the10mm(for 10-24mm)or 24mm(for 20-70mm).
7.Please make sure the focus ring remains unchanged and calibrate the object to the sharpest only through adjusting the back flange ring
8.Repeat Step3-7 for two to three times.when the best focus stays in a same position in all different focus distance, the calibration finishes. The situation may vary in different cameras, and please repeat the steps to make sure the focus is sharp in both wide angle and long focus distance.
9.Lock the screw rod on the back flange distance after calibrating.Theoretically the back flange need to re-calibrate after changing to other cameras.