The Dehaze tool in Lightroom can be found in the Effects panel in Lightroom. Its a very useful tool and can make a dramatic difference to how your final images look. So, what is it exactly and how do you use it?
Well, the clue is in the name, "dehaze". Yes, it reduces haze and fog in an image to bring back the colours that have been desaturated by atmospheric haze or fog. So, whenever you have an image where the colours look a bit flat due to atmospheric haze or fog, try using the dehaze to remove the haze or fog.
Another use for the tool can be to actually add haze or fog to an image. Now why do that you might be thinking? Well, with portraits, used sparingly, it can help soften an image, adding a low-key effect to the image. It doesn't work with every image and you will probably need to use a mask its effect is restricted to just the face of your subject. Also, you may want to turn a bright and clear day into one that looks like it was a foggy one!
So, what about images that don't have haze or fog in them, does the dehaze have anything to offer? Well, in my own experience it does. It's great at adding punch to an image and with skies, it has a similar effect as a polarising filter does. In fact, I am finding myself using it in lots of my images, not just to remove atmospheric haze but to boost contrast in the mid-tones, something that is not always easy to do using other tools such as contrast or the back slider in the Tone panel.
Here is a "before" and "after" pair of images where I used the Dehaze tool.
|AFTER - DEHAZE AT 100%|
Personally, I would dial down the Dehaze setting, adjusting bit by bit, all the while keeping an eye on the preview until I am happy with the result. I would use the Dehaze tool before any other tool and then once I am happy with its effect, I would then adjust the Clarity, Vibrance, Saturation tools until I was happy with the result. Sharpening and Noise Reduction would be left until last. All the while I would be checking the result at 100% to make sure no artefacts have been introduced.
Note: If there are spots in your image (either because of dust on an original negative/slide you have scanned or on the sensor if using digital), then the Dehaze tool will bring them up and you will then need to use the retouching tool (in Lightroom that would be Spot Removal - Q key).
So, here is the final image after I have applied all the corrections I wanted to.
Settings used were: Dehaze +75, Clarity +25 and Auto Tone.