Oh, it's possible.
I know that the photos with the hideous purple haze on the sides or corners are taken with my iPhone 5. My 4S on the other hand took beautiful clean shots without me ever having to worry about "pointing it wrong".
I started with the 3GS and have upgraded every year. I've had the 5 since launch day too. I remember feeling somewhat disappointed overall when I got it, and very disappointed with the camera. If it's not fixed this time around, I'll skip the upgrade for the first time since becoming an iPhone owner.
I have to agree with others in this thread... For the robust build quality, the looks, and the overall functionality, the 4S has been the best iPhone I've owned. My kid has it now and it's still going strong.
Shadowing the lens with your hand is a feature!!