Hi fredan, I think you are talking about Black thin border around the photos in Bridge, and this Black border disappears later. This is a feature of Adobe Bridge. When a photo is open is Bridge's content panel, Bridge first generates the thumbnail for that photo, and then generates the various size of previews for that photo. Bridge shows the thumbnail in Content panel. However, the previews are shown in Preview panel. The black thin border around photo suggests that previews are not generated yet, and the black border disappears as soon as previews are available. You can try the option highlighted in screenshot below to improve the time taken in opening a folder containing many photos. Thanks, Deepak Gupta
... View more