The invention provides a light source (1, 200), especially a portable light source (1, 200) used to illuminate a medical or precision mechanical working area, with a casing (2), with a light diode (4) held by the casing (2), with a primary focusing lens (6, 6a) held by the casing (2) in the direction of emissions (2a) from the light emitting diode (4), with a secondary focusing lens (8) held by the casing (2) positioned behind the primary focusing lens (6, 6a) in the direction of emissions (2a) from the light emitting diode (4), and that has a largely cylindrical recess (10), with the characteristic that a floor (12) of the recess (10) facing the primary focusing lens (6, 6a) is curved in the direction of the primary focusing lens (6, 6a).