There are three variables that need to be known in order to determine the most appropriate lens for an application:

• The distance from the camera to the object being imaged. This is usually expressed in feet or meters.
• The size of the object being imaged. This is usually the largest dimension, also in feet or meters, as long as the same units are used.
• The number of pixels that the object needs to cover in the image, usually using the larger of the horizontal or vertical dimension.

Using these variables, it is possible to calculate the optimal lens, since the sensor resolutions and pixels sizes of Boson, Quark2, Tau2, and legacy Photon cameras are known values. Note that these calculations become less accurate at very close ranges, or for very wide field of view lenses.

A simple calculator to help with lens selection for Tau2 and Quark2 can be found here.