I have to tried to find an answer via Adobe and Google. Still not able to figure out on how to read out XMP metadata for captions out of my photos. Checking the XMP data in InDesign shows info on Camera Make, Exposure etc. But if I use metadata fields from "Caption Setup" like "Camera" the caption shows <No data from link>. Fields where the XMP field name matches (e.g. "Lens") are ok. I need following fields for the caption: Camera Make, Exposure (aperture and speed) and ISO.