|Nikon D7000, ISO 100, f/8, 30s|
Fog is nature's bokeh. Do you like backgrounds that melt away into the creamy distance? Fog does that naturally, without the harsh fringing and optical nervousness that you get with cheaper lenses. It's an easy to use element in isolating foreground/background detail. However, for personal taste, I would consider the above example to be too much. This was shot from the Granville Island Public Market, looking north into downtown across False Creek. It's not a groundbreaking photo, but there are some interesting elements going on. The problem is that the veiling nature of the mist is dulling the overall impact of the photo.
Basically, fog is not so much a detail destroyer as it is a contrast suppressor. There's potential there; some detail is being recorded but it's recorded as low contrast detail. The first order of business is to create more contrast between the harder forms of the ships and the softer muted texture of the skyscraper lights. In whichever program you prefer, this would be to either use the simple contrast slider or to go for the more advanced curves/levels adjustment. It's better to use curves, as you want to deepen the dark forms of the ships without darkening the rest of the picture:
Bringing out the global contrast (with a curve adjustment) has produced more "pop" in the shoreline detail, but it has also increased the colour saturation. (Also, yes, there's a dust big 'ol spot in the upper left, but we'll get to that later.) The orange glow of the sodium lights is a bit much here, so the picture requires a colour balance adjustment to turn down the reds and to feed in a bit more blue:
After re-balancing the colour, the image is a bit closer to the original out of camera image. The final step is sharpening. I like to use a two-pass approach. The first pass is to use a wide area/low strength unsharp mask in order to bring out microcontrast. This technique is very good a lifting details out of a veiling haze, and is used hear to essentially "dial back the fog." The second unsharp mask pass is with high strength/low area in order to crisp up borders and edges. Generally it's good to do sharpening selectively so as to not accentuate noise, but in this case there's no real need to be ultra careful as a little bit of extra grain enhances the appearance of mistiness. While we're at it, we'll get rid of that dust spot as well:
And here we have the final interpretation of that image. Compared to the out of camera image, the general appearance of the fog thickness is less, and the enhanced detail of the pleasure craft on the shoreline gives the eye something to anchor on. However, the haziness of the downtown skyline is maintained, so you still get the sense of a foggy atmosphere, it's just that the picture no longer hits you over the head with it. This was the potential that was hidden in the out of camera shot: the different textures of the environment coming together. That would be: the glassy smoothness of the water, the crisp edges of the boats, and the diffuse mist of the skyline.