In order to determine the lowest light level at which a digital camera can still deliver acceptable images, acceptance thresholds must be established for all related image quality factors. ISO 19093 describes these factors and how they can be measured. However, the acceptance thresholds may depend on the application for which the images were captured, as well as on people's individual tolerance for degradation in the different image quality factors. To generate a standard set of tolerance levels for photographic applications, a psychophysical experiment was performed, as described in this paper. First, a group of 23 image quality experts participated, followed by 16 people with no specific experience in imaging. The same experiment was repeated for the specific application of security cameras. The set of images, as well as the questions asked of the participants, were adapted to the use case. For the security application, 27 participants with a background in security camera imaging took part.