The field angle w is determined by the sensor length S, the focal length f and magnification β:

## Field angle

{!{!{w=arctan\left(\frac{S}{2\cdot f\cdot (1+\beta)}\right)}!}!}

The field angle is used for calculating the edge intensity.### Imaging Parameters

Schematic depiction of the imaging system and definition of variables used.

f = Lens focal length (mm)

S = Sensor length (mm)

L = Length of Region of Interest (ROI) of object (mm)

a = Object range (mm)

a’ = Image distance: Distance from sensor to HH’ (mm)

β = Magnification

w = Field angle

OO’ = Distance from sensor to measured zone (mm)

s’A = Flange focal length (mm)

∆s’ = Lens extension (mm)

LT = Tube length

A = Working distance (mm)

HH’ = Principal point distance (mm) (can lengthen or shorten OO’)

s’K = Camera flange length consisting of focus adapter series FA22 and extension rings series ZR (mm)

LO = Lens length (mm)