Possible reasons for poor quality photos on the iPhone 16 are:
Improper camera settings: Go to "Settings" -> "Camera" -> "Formats" and make sure the "High Efficiency" mode is not selected. This mode reduces image size and quality for storage optimization on the device.
Lens grime: Gently wipe dust or smudges from both sides of the lens and the flash area with a soft cloth.
Camera software or hardware issues: Restart your device and check for iOS updates.
Poor lighting conditions: Try taking photos in well-lit areas.
Incorrect exposure settings. Open the "Camera" app and double-tap on "Exposure Control". This will display camera settings in a pop-up window. Swipe to find "Exposure", lightly tap it to select, and then swipe again to adjust it.
If the problem persists, contact Apple support.