The invention relates to an aperture for a photo or film camera lens assembly or for a photo or film camera, where aperture has a device, which defines an ellipse-like opening, at least in part, the primary and secondary axes of which are stationary, by means of which, in the case of vertical alignment of the ellipse-like opening the aesthetic image effect from anamorphic lenses is produced in the unfocused region. The aperture can also include a conventional iris. The ellipse-like opening can be formed by a disc having a fixed, ellipse-like opening or by lamellae forming a linear aperture and which can be moved perpendicular to the main axis of the ellipse-like opening.