# colour.contrast.pupil_diameter_Barten1999#

colour.contrast.pupil_diameter_Barten1999(L: ArrayLike, X_0: ArrayLike = 60, Y_0: Optional[ArrayLike] = None) NDArrayFloat[source]#

Return the pupil diameter for given luminance and object or stimulus angular size using Barten (1999) method.

Parameters:
• L (ArrayLike) – Average luminance $$L$$ in $$cd/m^2$$.

• X_0 (ArrayLike) – Angular size of the object $$X_0$$ in degrees in the x direction.

• Y_0 (Optional[ArrayLike]) – Angular size of the object $$X_0$$ in degrees in the y direction.

Returns:

Pupil diameter.

Return type:

numpy.ndarray

References

[Bar99], [Bar03], [CKMW04], , [WY12]

Notes

• The Log function is using base 10 as indicated by [WY12].

Examples

>>> pupil_diameter_Barten1999(100, 60, 60)
2.7931307...