Originally posted by Mike Cash Have you adjusted the diopter?
I had exactly the same thing once when I was out on a nightshoot and BOY did I panic that I'd broken it somehow. If fact it turned out to be just the diopter, it had shifted somehow. Subsequent investigation revealed that it got caught when I took the camera out the bag.
Enialet, are you familiar with what the diopter is? If you look through your dslr eyepiece, you should see a ridged protusion that you're able to adjust - it looks something
like this. It's that ridged thingamygummy between the camera body and the rubber eyecup on that pic - this is adjustable (for people with poor eyesight) - perhaps yours is slightly loose and got shifted?
I have to say I'm having a hard time working out what else it might even be as that internal LCD isn't affected by lenses. Would a wonky mirror have such an effect?