On my linux workstations I use Aeskulap, which is a less optimal solution as it does not show 3D datasets very well. So I am still looking for “the right solution”.
I, for the time being, import the images from my cameras with the filemanager into a directory on my file server, using a standardized format. I.e. one directory per patient with a format of SSnumber.FirstnameLastname. Importing the images via the EMR would of course be a great feature, as renaming the images to reflect the character of the image would be an advantage. I.e. Date_IO_Frontal for the intra oral frontal pic.
The viewers I use for clinical photos are IrfanView for Windows and gThumb for linux, thus they communicate via the filesystem protocol.