Abstract: Apparatus for measurement of the exposure time and/or for controlling the time for exposure of a photographic camera having a measuring unit generating an exposure time signal in response to object brightness. The apparatus comprises an oscillator, a frequency transforming device, a comparator means and a display means. The frequency transforming device generates output signals offset in frequency with respect to one another, and these output signals define an elapsed time which is compared in the comparator means with the exposure time. The display means are connected to the comparator means for indicating the results of the comparison.