Beginning diagnostic purposes, go to Settings | Applications | Tap the "All" tab | Scroll down to "Camera" | Upon proper storage information display, Click "Force Stop" and subsequently "Clear data".
Then try open up the camera once again and take a couple shots, and provide feedback if you still encounter the same issue...
Also, would like to know how many camera apps were installed with the device. Camera apps here includes apps that require the use of the camera for another purpose. I've personally come across apps that disable and glitch other apps, especially built-in apps like the "Camera" app on your android device. If you have installed a camera app recently, you could try uninstalling those apps gradually; reboot your phone - and see if the problem is solved.