To provide a diaphragm device with which an illumination angle can be quickly and easily modified.

A diaphragm arrangement 100 for generating an oblique illumination comprises a carrier element 130, an iris diaphragm element having a variable iris diaphragm opening 111, another diaphragm element 120 having a diaphragm opening, and an actuation element 140. The diaphragm element 120 covers a portion of the iris diaphragm opening when being in a first position relative to the carrier element, and is mounted rotatably around a first rotation axis A, and rotation of the diaphragm element 120 around the first rotation axis A changes the portion of the iris diaphragm opening which is covered by the diaphragm element 120. The actuation element is coupled to the diaphragm element 120 via a coupling device, and rotation of the diaphragm element 120 around the first rotation axis A is generated by an actuation of the actuation element.