Good day MPD12,
If you are having an issue with being unable to import photos from your Kodak camera into the Photos application on your iMac, there are a number of things you may want to try to get this working.
First, be sure to follow the instructions on this page to do the import -
Import photos from a camera or mobile device - Photos Help
If this is not working, if your camera has storage media that fits the iMac's SDXC Card slot, try removing the memory card from your camera, inserting it in the slot and follow the directions on this page -
Import photos and video from storage media - Photos Help
If neither of these methods work, try using the Image Capture application to import from either the camera or the card. Once imported into the computer the pictures can be brought into the Photos application. See this article -
OS X Yosemite: Import photos and movies from your camera
Thanks for using Apple Support Communities.
Safe computing,
Brett L