The Camera tag contains four groups which are used to control those parts of the Maxwell camera which have no matching parameter in C4D. The Camera tag may be attached either to a C4D camera, or to the Scene you are working with.
Exposure
EV
EV, or Exposure Value is a number used to express the basic exposure which will be seen in the exported MXS. EV may be used to set the exposure directly, where brighter scenes will require a higher EV, or it may be used as an exposure readout when setting fStop, Shutter, and ISO manually. For example, an outdoor photo during the daytime may require an EV somewhere around 12-16, while a dark candle-lit scene may require a value much lower, maybe around 4-6. Charts containing recommended EV for various lighting conditions can be found online (see the end of this manual for a chart from wikipedia.org).
EV is not actually a parameter found on Maxwell cameras – it is a theoretical value which is continuously figured by the plugin itself. The 'Lock exposure to EV' option is provided for one basic reason: while exposure may be adjusted manually using different combinations of fStop, Shutter, and ISO, it is possible to adjust the DOF (depth of field) on the camera using the fStop without also affecting the overall exposure of the shot when the plugin is allowed to maintain a given EV. This allows you to adjust the camera's exposure and DOF on a totally independent basis, and this makes setting up exposure much easier and more predictable.
...
Specified in units of 1/second, this parameter controls how long the camera's Shutter is to remain open. As with the ISO parameter, it is not necessary to adjust the camera's Shutter directly when 'Lock exposure to EV' is enabled. For convenience, the current FPS value is also shown here.
...
Lens and aperture
The parameters in this section determine the type of lens to use, and also the angle and number of blades used in the camera's aperture, when the Diaphragm type is set to 'Polygonal'. These properties affect the 'bokeh' effect seen in highlights located in out-of-focus portions of the image, which can also be customized using the Custom Bokeh option & parameters. You can get more information about these parameters here: https://nextlimitsupport.atlassian.net/wiki/spaces/maxwell/pages/22685010/Camera+parameters#Sensor
Rotary Shutter
These parameters express the camera's theoretical rotary shutter angle given a specified frames-per-second rate. The FPS value is always taken from the Frame Rate setting in the current C4D Render Settings.
Z-Clip Planes
When enabled, Maxwell Render will clip any geometry nearer or further than the Near and Far distances defined here. These distances will also be shown in the viewport as red and blue 3D planes when this section is enabled.
...