Method for calibrating cameras of a multichannel medical visualization system and medical visualization system

A medical visualization system, comprising:

• a plurality of channels for capturing and imaging a capturing region,
• a camera for each of the plurality of channels, configured to capture the respective capturing region imaged by way of the channel,
• a common mechanical magnification optical unit, and
• a control device,
• wherein the control device is configured, for calibration purposes, to determine a respective magnification center for each of the channels and control the common mechanical magnification optical unit in such a way that at least two magnification levels are set, and to identify an image region which does not move or which moves the least across the magnification levels for each of the channels in image representations which are captured at the at least two magnification levels by means of the respective camera,
• in each case proceeding from the respectively determined magnification centers, to define an image portion for each of the channels in the captured image representations with the respectively identified magnification center as the center, and
• to restrict an output of the captured image representations at all magnification levels to the image portion defined for the respective channel.