Zeiss Dimension Manuel D'utilisation page 20

Adjusting focus and aperture
ZEISS Dimension lenses are manual lenses, meaning focus and
aperture are adjusted directly at the lens. Use the respective
adjustment ring on the lens (8 and 7). Use the included fixing
screws (3 and 7) to lock the adjusted focus and aperture settings
US
to prevent inadvertent adjustment. Focus and aperture settings
are infinitely variable between the indicated extreme values.
Adjusting the back focal distance
ZEISS Dimension lenses have a nominal flange focal distance
(= distance between the lens mounting surface and the camera
sensor) of about 17.53 mm in air with infinite object distance
at delivery. To ensure the optimal image quality, it is necessary
to compensate the tolerances of camera bayonets by adjusting
the back focal distance.
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