You can protect picture and movie files from accidental erasure by giving them protected status on your Nikon D5500. After you take this step, the camera doesn’t allow you to delete the file from your memory card, whether you press the Delete button or use the Delete option on the Playback menu.
You can also use the Protect feature when you want to keep a handful of pictures on the card but delete the rest. You can just protect the handful you want to preserve. Then set the Delete menu option to All and dump the rest. The protected pictures remain intact.
Formatting your memory card does erase even protected pictures. In addition, when you protect a picture, it shows up as a read‐only file when you transfer it to your computer. Files that have the read‐only status can’t be altered until you unlock them in your photo software. (In Nikon ViewNX 2, select the image and then choose File→Protect Files→Unprotect.)
Remember, too, that locking the file prevents you from assigning a rating to it — so rate photos before giving them protected status.
To protect a file, take these steps:
Display the picture or movie file you want to protect in single‐image view.
Or, in Thumbnails view or Calendar view, select the file thumbnail. (Either tap it or use the Multi Selector or Command dial to surround it with a yellow selection box.)
Press the AE‐L/AF‐L button.
See the key symbol to the lower left of the button? That’s your reminder that you use the button to lock a picture. A key symbol also appears with locked photos during playback.
Press the AE‐L/AF‐L button to give an image protected status.
To remove protection, display or select the image and then press the AE‐L/AF‐L button again.