To correctly determine the flange back distance of a uEye camera, you need to consider the distance between the lens flange and the active area of the sensor and, additionally, the type and thickness of any materials inserted into the optical path.

The "distance in air" between the threaded flange and the active area is 17.526 mm with C-mount lenses and 12.50 mm with CS-mount lenses.

This "mechanical distance" can change due to the material-specific refractive index of the inserted materials. The glass cover of the sensor and all filters inserted into the optical path (see Filter types table) must be taken into account in the calculation.

Fig. 298: Calculating the flange back distance (schematic illustration)

Designation Description a' Distance from threaded flange to active sensor area (flange back distance), defined as: •17.526 mm for C-mount •12.50 mm for CS-mount x Distance from threaded flange to PCB e Distance from active sensor area to PCB d Thickness of the glass cover of the sensor f Filter thickness (optional) n Refractive index (n = 1.5) h Maximum sensor height above the PCB

You can use the following formula to calculate the mechanical flange back distance:

Calculation example: UI-154x-xx with IR-cut filter (a = 17.526 mm, d = 0.525 mm, nGlass = 1.50, f = 1 mm, nFilter = 1.53; see Filter types table):

The tolerances for the position accuracy of uEye camera sensors are given in the D: Specifications chapter for each camera family.

Calculating the flange back distance for uEye cameras with C-mount

For uEye cameras with C-mount, the flange back distance is a' = 17.526 mm.