1. A digital camera ( 400 ), comprising a sensor array ( 410 ) having image pixels (I) for capturing image data during an exposure period (EP), and focus-detection pixels (F) for determining focus information in a first mode of operation; wherein the digital camera ( 400 ) is adapted for obtaining brightness related data (v) from the focus-detection pixels (F) in a second mode of operation, during capturing of an image by means of the image pixels (I), the digital camera further comprising a controller ( 428 ) adapted for determining the exposure period (EP) based on the brightness related data (v) obtained from the focus-detection pixels (F).