One of the biggest problems that almost every photographer has with flash is that they don't know how to meter with it unless you've had extensive experience. And so today's questions comes from a place where it honestly shouldn't be a problem but it is.
The situation: you're shooting with a flash connected to the hot shoe and the flash is in TTL mode. The camera meter says that you're underexposed but the image isn't--in fact it's overexposed in your eyes. Why is that?. thephoblographer.com