So you have a low-contrast, hazy image like this.

Shanghai Morning 1

Yup, it is a hazy morning in Shanghai. Now what?

You have several options.

• Live with it. Haze is not always bad! Sometimes (“foggy mornings” come to mind) you want this sort of low contrast.
• Put a sharp object in front. This is a very powerful technique: it makes the haze into a benefit, as in the boat image below.
• Finish in post-production. In the last image below, I increased exposure until the histogram hit the right side of its box; then I pulled down “blacks” in Lightroom to make the blacks black – i.e. until the histogram hit the left. You can use “Levels” in Photoshop to achieve the same result.

Like this:

Hong Kong Harbour

Shanghai Morning 2

And.. you are shooting RAW, right?