Set the focus point

Change exposure of the photo

Tap on the screen where you want the focus of the photo to be. A square will appear, that is the focus point.
Tap on the brightest part of the screen and then tap on the darkest part of the screen, that should set the exposure.

Take a quick photo with the iPhone

HDR High Dynamic Range

Press your home button and swipe upwards on the camera icon, the camera will start up, use the volume button on the camera as a shutter.
Take photos in HDR by tapping on the Options button and selecting HDR