Anyone that has taken photos in the hot and humid Caribbean has probably encountered the brutal haze - especially if you take long telephotos across water. If you have had this problem, chances are that you have tried UV and Haze filters, and have discovered they do not work. The good news is that there is a simple solution.
Hazy photo taken in Cartagena, Colombia - Nikon D90 w/ Nikkor AF 70-300mm f4~5.6 @ 180mm.
The photo as shown above is what the camera captured on a hot-hazy afternoon in Cartagena, Colombia. This kind of yukky photo is really disappointing. The problem is that there is no dynamic range. If we look at the photo's histogram, it is really apparent where the problem lies.
The histogram for the photo above is shown on the left, while a typical histogram is shown to the right. A histogram shows all of the values from the darkest areas (left) to the lightest (right).
A typical histogram on the right will have tones in the entire visible spectrum from dark to light. This range is called "dynamic range".
The haze histogram on the left shows that there is only a narrow band of tonal values, and this photo could be said to have little dynamic range. To correct the haze, we must increase the photo's dynamic range. Fortunately, most photo processing software has controls to easily change the dynamic range. While I am using Nikon's Capture NX2 v2 in this example, most good photo processing software has this function, including Adobe Lightroom, Photoshop, and others.
To correct the dynamic range, simply move the controls of the histogram to "capture" the existing dynamic range.
Step 1, shown to the left is done by sliding the dark value slider to the right until it meets the photo's darkest values.
Step 2, shown to the right is adjusted in a similar fashion by sliding the highlight value slider to the left until it intersects the highest value of the photo.
That's it - you are done.
And to confirm the results, the histogram of the corrected photo reveals typical looking values. I think you'll agree that a simple change of values in the histogram results in a much improved photo.
This procedure can be used on with either RAW files or high quality JPGs to great success (although results are obvously better with RAW files). So dig out all of those yukky photos you took that never made it to your travel portfolio and begin correcting haze.