A photographic apparatus which can accept cassettes for high-speed or lower-sensitivity film has a mechanical or electronic switch which automatically deactivates a light-emitting diode which serves to indicate the intensity of scene light as soon as a cassette for high-speed film is properly inserted into the body of the apparatus. Such cassette further causes a filter to move out of register with the light-sensitive resistor which is in circuit with the diode and is exposed to scene light. The diode is also deactivated if the diaphragm is adjusted to furnish an aperture of maximum or minimum size; alternatively, the diode is deactivated only when the body of the apparatus contains high-speed film and the diaphragm is adjusted to furnish an aperture of maximum or minimum size.