The ISO 18844 standard that is on the way defines a flare measurement method for a camera lens system similar to the measurement described in the older video standard IEC 61146. In addition it addresses the measurement of flare over the imaging field and also the measurement of devices that do not allow for adjusting the exposure like mobile devices. The paper provides an overview over the sources of “unwanted light” which the standard was originally supposed to address and potential ways to measure these. The current draft version only addresses the standard flare caused by a diffuse white plane mostly within the field of view of the camera. For this kind of flare three different measurements approaches are defined using a single or multiple exposures depending on the level of control the user has over the exposure of the image. Measurements will be presented as well as inter lab comparison issues that came up during the development of the measurement procedure.