How to Open a CTG File
A CTG found on a Canon camera card is normally a catalog or control file, not a photograph to open. To view your pictures, look in the card’s DCIM image folders for JPG or RAW files instead.
Choose what you need
Find the photographs instead of opening CTG
- Connect the camera or memory card without modifying its contents.
- Open DCIM and the camera’s numbered image subfolders.
- Copy the actual image files to your computer.
- Open JPG files with an image viewer, or RAW files with compatible photo software.
Canon’s software guide distinguishes the image folders from camera configuration folders such as CANONMSC. Folder naming varies between models.
Why CTG to JPG conversion does not recover photos
A catalog entry and a photograph serve different purposes. Changing the CTG extension to JPG does not create the image data a photo viewer needs. If someone sent you only CTG files, ask them to resend the files from the image folders.
If the card shows control files but the expected photos are missing, preserve the card and its backups. Stop taking new photographs on that card while deciding whether recovery is needed, because new writes may replace deleted data.
Should you edit or delete Canon CTG files?
Do not manually edit camera control files to fix missing photographs. Canon advises leaving configuration folders alone. After copying and verifying the actual pictures, use the camera’s own supported image-management or card-formatting workflow when you intentionally want to erase the card.
If a CTG did not come from a Canon camera, establish its originating application before applying these instructions. This guide addresses the camera-card context.
Frequently asked questions
Can I convert a Canon CTG to JPG?
A Canon catalog or control file is not the photograph. Locate the actual image under DCIM; renaming CTG to JPG does not recover it.
Where are my Canon photos if I only see CTG?
Check the DCIM folder and its image subfolders. Canon’s control folders are separate from the folders containing photographs.
Sources and further reading
Opening routes checked against the references below on October 11, 2026. Device menus, software support and protection policies can change.