Using Curves in HDR Processing

Article by Malcolm MacGregor

If I were to suggest just one tool for you to learn in photoshop, it would be the Curves tool. The curves tool is an extremely powerful tool. It’s able to increase contrast, saturation and can even change the color balance of your image. It is, by far, the tool I use the most in my HDR processing workflow.

Let’s talk about how I used the Curves tool to process this photo of the Okaloosa Island Fishing Pier in Ft Walton Beach Florida.

This photo is a 6 exposure HDR, merged in Photomatix. Generally, when I merge my exposures in Photomatix, I try to keep them looking pretty flat. I always want to make sure that I am doing the bulk of my processing in Photoshop. So here is the photo after merging in Photomatix:

 Now I am ready to begin with my curves adjustments. The first thing I do is to break the photo up into sections. This photo has 3 main sections:

  1. Water and Sand
  2. Pier
  3. Sky

I create curves adjustment layers specifically for these individual areas using masks on the adjustment layers. If you don’t know how to use masks, I highly recommend you look it up! It’s actually very easy and allows you to apply adjustments to specific parts of a photo.

Lets start with the Water and Sand areas. The first curves adjustment layer I did looked like this:

I then did another curves layer for the sand only (masking out the water portion) to brighten it up even more:


My next curves adjustment was for the small area where the water was splashing against the pier. I wanted the splashes to really stick out, so I lightened them up a bit more:

The last curves adjustment layer I did on the sand/water portion was to add tones to water. I changed the drop down box that normally says “RGB” to “Green”. This will allow us to affect the green channel only. By pulling the top right point straight to the left, I add very subtle green tones to the water:

Now that I’ve got the sand and water looking the way I want, I’ll start on the pier. I only did one curves layer for the pier, to brighten it up and add lot’s of contrast:

The next section of the photo to work on would be the sky. I did 3 curves adjustments for the sky, 1 for contrast and 2 for toning:

Red Tones:

Blue Tones:

And this completes the curves adjustments! Leaving us with the final photo:


You can see we’ve made quite a transformation from the original. The final photo has much more saturation and contrast without looking overdone. We were able to pull a lot of detail and color out which makes for a more dramatic presentation. Some things to keep in mind:

  1. Not all of your curves adjustments will look the same. This is the point of masking, so you can apply different adjustments to different portions of the photo.
  2. Take your time with the masks. Sometimes it is useful to use a plug-in such as Topaz’s Remask. Remask makes it easy to get very clean selections.
  3. You’ll see that when you increase contrast with curves, you’ll also increase saturation. If the saturation is too much for you, change the blend mode to “Luminosity”. This will allow the curves layer to keep the contrast, but not the saturation.
  4. Experiment and have fun!

Here are some other photos where I’ve used multiple curves adjustment layers:



I hope you’ve found this curves tutorial useful! If you have questions, feel free to email me at

You can find more of my work on my website

You can find more info on HDR and even watch full in-depth HDR tutorials at