Some users have reported that the iPhone 4′s camera app crashes or freezes, either right after it is opened or when the user attempts to take a picture
This problem may be resolved by following the first three of the 4 Rs, as described in our iPhone 4 troubleshooting guide. This list of escalating fixes that can solve a surprisingly large number of iPhone 4 problems. Try solution #1 first; if it’s not successful, try #2; if #2 is not successful, try #3.
- Reboot (hard reset). Hold down the sleep/wake and home buttons simultaneously for roughly 15-20 seconds, until the screen powers off then an Apple logo appears, which signifies a reboot. Some problems may require (oddly) that this procedure is performed twice.
- Reset all settings. It appears that the reset may restore disengaged hardware components and clear corrupt data that prevents proper operation. Navigate to Settings > General > Reset > Reset All Settings. Note that this will erase stored messages, passwords and other information.
- Restore, but not from backup. Ba holdover data from iPhone backups (especially those created for previous iPhone models) can cause various issues. Restoring as a new phone will delete contacts and other data, but may resolve the problem. To do so, connect your iPhone or iPod touch to your computer, click “Restore” in iTunes, then choose “setup as new phone.”
Turn phone off for several minutes
Interestingly, some users have reported that turning their phones off (completely, by holding down the sleep/wake button on top of the phone then sliding it of) for roughly 15 minutes then turning it back on resolves this issue.