I love the look of fog or mist in images. To me, it adds mystery and intrigue to the scene, but one unfortunate side effect is that it also is very hard for your camera's built-in light meter to read properly, so you get what you're seeing with your naked eye. Of course, like so many things, there's a trick of the trade that helps you get a good exposure that keeps that foggy look. Start by aiming at the fog itself, and then hold your shutter button halfway down (which tells your camera to take a reading of that area). Now, go to your camera's exposure compensation control and increase the amount of exposure by one stop (basically, what you're doing is disagreeing with what the camera read for the fog, and overriding it by increasing the exposure by one stop). On Nikon cameras, you do this by holding down the exposure compensation button on the top right of the camera (just behind the shutter button), and while you're holding that button down, turn the command dial on the top back of the camera to the right until you see +1 in your camera's viewfinder. On Canon cameras, you'll set the shooting mode to anything but manual, and then you'll spin the quick control dial (the big one on the back of the camera) to the right until you see +1 in the camera's viewfinder. Just one reminder: when you're done shooting your fog shots, set your exposure compensation back to zero, or you'll be shooting the rest of the day with every shot overexposed by one stop.