IPhone 4 Flash pictures show up all black?

I recently noticed today when taking pictures with flash, the whole picture turns out completely black. I've had my phone for only 1 year and it's never done this! The flash right next to the camera itself performs shorter when taking a picture, and the end result is all black.

What's wrong with it? Do I need a new phone?

Take out battery and sim. Wait a couple of minutes before putting them back. This is like a soft reboot. Try to take a photo again of something that has a mixed range of tones.

If that doesn't work then restore the phone toits original factory settings. If that doesn't help then the phone is faulty.

The flash in an iPhone is not very powerful. Unless you are taking a photo of something a couple of feet away, it does not have enough power to illuminate the scene. Smartphone cameras are very limited in what they can do.

LED flashes on smartphones are pretty puny. Anything over 2-3 feet away will be in darkness.

Have you tried contacting Apple? By phone or email?

It means your camera's flash is not strong enough to shoot in the dark.