Observation device, particularly medical observation device, comprising: - an image acquisition unit that is integrated into an optical instrument and that comprises at least one image sensor, particularly a stereo-image acquisition unit comprising two image sensors, - an image display unit that is arranged to display image data provided by the image acquisition unit, and - an image processing unit for image processing procedures, wherein the image acquisition unit is configured to provide recorded images having a predefined recording pixel quantity (n a), wherein the image display unit is configured to display display images having a predefined display pixel quantity (n b), wherein the recording pixel quantity (n a) is equal to or greater than the display pixel quantity (n b), wherein image pixels of the display pixel quantity (n b) are obtainable from the recording pixel quantity (n a), wherein, for providing views having different magnifications, subsets of the recording pixel quantity (n a) are selectable to form the display pixel quantity (n b), characterized in that - a control unit having a multi-axis input module is provided, - the input module is configured for controlling image acquisition parameters and display parameters, - the input module is coupled with the image acquisition unit for controlling at least one image acquisition parameter, and - the input module is coupled with the image display unit for controlling at least one display parameter, - the input module is arranged as single-hand input module and provided with an actuation element (52, 90, 104), - the actuation element (52, 90, 104) is arranged as four-axis actuation element having four actuation axes (80, 82, 84, 86), wherein an actuation of the first actuation axis defines a magnification and a size of an area of the display images in the recorded images that is associated with the magnification, an actuation of the second actuation axis defines a focus setting, an actuation of the third actuation axis effects a movement of the area that is covered by the display images in an area that is covered by the recorded images, in a first movement direction, and an actuation of the fourth actuation axis effects a movement of the area that is covered by the display images in the area that is covered by the recorded images, in a second movement direction that is inclined with respect to the first movement direction. - an image acquisition unit that is integrated into an optical instrument and that comprises at least one image sensor, particularly a stereo-image acquisition unit comprising two image sensors, - an image display unit that is arranged to display image data provided by the image acquisition unit, and - an image processing unit for image processing procedures, wherein the image acquisition unit is configured to provide recorded images having a predefined recording pixel quantity (n a), wherein the image display unit is configured to display display images having a predefined display pixel quantity (n b), wherein the recording pixel quantity (n a) is equal to or greater than the display pixel quantity (n b), wherein image pixels of the display pixel quantity (n b) are obtainable from the recording pixel quantity (n a), wherein, for providing views having different magnifications, subsets of the recording pixel quantity (n a) are selectable to form the display pixel quantity (n b), characterized in that - a control unit having a multi-axis input module is provided, - the input module is configured for controlling image acquisition parameters and display parameters, - the input module is coupled with the image acquisition unit for controlling at least one image acquisition parameter, and - the input module is coupled with the image display unit for controlling at least one display parameter, - the input module is arranged as single-hand input module and provided with an actuation element (52, 90, 104), - the actuation element (52, 90, 104) is arranged as four-axis actuation element having four actuation axes (80, 82, 84, 86), wherein an actuation of the first actuation axis defines a magnification and a size of an area of the display images in the recorded images that is associated with the magnification, an actuation of the second actuation axis defines a focus setting, an actuation of the third actuation axis effects a movement of the area that is covered by the display images in an area that is covered by the recorded images, in a first movement direction, and an actuation of the fourth actuation axis effects a movement of the area that is covered by the display images in the area that is covered by the recorded images, in a second movement direction that is inclined with respect to the first movement direction.