Dehaze versus Offset


Today’s Question: The Dehaze slider on the Effects panel in Lightroom CC has generated a lot of excitement, and it is certainly useful to have this tool in Lightroom. However, it appears to me to do the same thing as the Offset slider on the Exposure adjustment layer in Photoshop, which has been around for some time. Are they different?

Tim’s Quick Answer: The Dehaze adjustment and the Offset slider in the Exposure adjustment can provide somewhat similar results in many cases, especially as it relates to the reduced appearance of haze in a photo. However, I would say that the Dehaze adjustment is a bit more sophisticated, and is certainly beneficial in many cases.

More Detail: The Exposure adjustment in Photoshop (available in Photoshop CS3 or later) was actually designed primarily for 32-bit per channel images. In other words, it is best suited to high dynamic range (HDR) images that have been processed to produce an image with a truly high bit depth of 32 bits per channel rather than the more typical 16 bits per channel. That said, this adjustment can still be used very effectively on 16-bit per channel images (and even 8-bit per channel images). You can find the Exposure adjustment as an adjustment layer on the Layers panel, or via the Image > Adjustments menu.

The Offset slider that is included as part of the Exposure adjustment enables you to lighten or darken the shadow areas of a photo with minimal impact on the highlight areas. If you use the Offset slider to darken the shadows, the result is very similar to the Dehaze adjustment available in Adobe Camera Raw or in the Develop module in Lightroom.

In other words, darkening the shadows using the Offset slider will enhance local contrast in the image and reduce the appearance of haze.

However, the Dehaze adjustment is a bit more sophisticated, with some fine-tuning applied to overall contrast levels as well as color balance and saturation. The result in many cases is that you can produce an effect with Dehaze that is less harsh than the effect you might achieve with the Offset slider.

That said, the two sliders are very similar in terms of what can be accomplished for a photo. In other words, if you’re using an older version of Photoshop that includes the Exposure adjustment but does not include the Dehaze adjustment, you could certainly use an Exposure adjustment layer to achieve much the same effect that would otherwise be possible with Dehaze. You’ll likely need to add a few additional refinement adjustments if you’re using Offset, but frankly you will often need to make adjustments (especially to color) when using the Dehaze slider as well.

So while I do find that the Dehaze adjustment provides better results than what is possible using the Offset slider available with the Exposure adjustment in Photoshop, the reality is that both provide very similar possibilities for reducing the appearance of haze within a photo.