I don't know about digikam and I don't have a digital camera yet. ( there is still time to get me one for Christmas )
Anyway, the last time I helped someone, we used gphoto to grab images and here are some notes from that...
#list the available commands for gphoto2
#list the available files on the detected camera
gphoto2 --auto-detect -L
#download all files from the detected camera to your present directory
gphoto2 --auto-detect -P .
#list all information about your detected camera
gphoto2 --auto-detect -a