I mostly save as Photoshop.psd in Artlantis, to be able to edit in Photoshp using the layers.
Save as .jpg in high quality to place on layouts in Archicad. This will give you simplest handling and smallest pdfs when you Publish from Archicad.
When you import the pictures into Archicad, remember to set their resolution (dpi) in the Picture tool's settings box.
AC4.1-AC26SWE; MacOS13.5.1; MP5,1+MBP16,1