Reply To: Adobe RGB to CMYK vs. sRGB to CMYK

Actually Edit > Convert to Profile does NOT change any image data. That just changes data inside the InDesign document (such as Swatches).

In general, though, if you place one sRGB image one Adobe RGB image, and then export to a PDF/X-1a, they’ll both be converted to CMYK properly. Nothing wrong with the photographer using Adobe RGB.

I would suggest changing the Destination Profile (in the export pdf dialog box) from SWOP to Gracol or Fogra39 (or fogra29 if it’s uncoated). That’ll likely be a better CMYK conversion.

I explain InDesign’s color management (including working with photoshop and illustrator) in detail in my Lynda.com title here.