Owners of Fujifilm’s MK18-55mm T2.9 cinema lens may want to look at their serial number; Fujifilm is voluntarily inspecting a batch of lenses after users reported the iris blades did not move properly.
After an internal investigation, Fujifilm identified a partial production light of lenses that may have a manufacturing defect causing the issue. The company isn’t issuing a full recall but is inspecting lenses within the serial number range for free. Fujifilm did not clarify if any lenses with the error would be repaired or replaced.
A lens’ iris is the set of blades that move to change the size of the aperture. As a cinema lens specifically designed for video work, the MK18-55mm has an aperture ring that allows the aperture to be controlled while recording to adjust the depth of field. While Fujifilm didn’t say what the issue was beyond the blades “not moving correctly,” the blades would affect how smoothly the aperture changes during recording. The iris blades also determine the shape of the background bokeh.
The inspection only affects lenses with the serial numbers between 75A00001 to 75A00354 — the serial number is located near the ring on the lens mount side, which is about the center of the lens. Fujifilm users that have one of the affected lenses are asked to contact the shop or dealer where the lens was purchased for further information about sending the lens in for an inspection.
The MK18-55mm T2.9 is a high-end cinema lens with a wide aperture announced just over a month ago, designed for 4K video. The new MK cinema lens series was the company’s response to more users picking up Fujifilm bodies for video work and the lenses are available in both a Fujifilm X and Sony E-mount. Along with the 18-55mm released earlier in March, the company also plans to launch a 50-135mm T2.9 lens in the same series this summer.