If you've been in the world of digital photography for even a short length of time, you will probably be aware of HDR photography. HDR (high dynamic range) is a process by which you combine multiple exposures to create an image with a greater dynamic range of light – in other words, you end up with fewer overexposed and underexposed areas in your scenes.
The problems of typical HDR are many, and extremely well documented. Essentially tone-mapping, which is the most common method for creating HDR images, can be extremely messy. While you may be able to stretch the available light in your image through tone-mapping, you may also be left with a noisy, soft, oversaturated and surreal looking image. This isn't always the case, but more often than not the results don't do justice to your image.
The question then remains, is there a better alternative? Fortunately, the answer for us is a big resounding yes. It is a process by which you manually blend the bracketed images in Photoshop, and is known as exposure blending or digital blending.
Rather than get into the fine detail about why exposure blending is superior to HDR methods, I've included a video of mine below which will do that. This article, instead, will show you a very basic, but highly effective method for blending your own exposures in Photoshop.
Before you begin the tutorial, I'd like to show you some examples of my images, before and after exposure blending. In each, you can see the underexposed image which exposes for the brightest parts of the frame, and a brighter image which exposes for the rest of the image.
How to Blend Exposures in Photoshop using Apply Image
Your goal in the following steps is to blend two exposures. You have a normal image with overexposed highlights. You also have a darker exposure where those overexposed areas are now nicely exposed. You want to recover those overexposed (clipped) areas in the brighter exposure from the same areas in a darker exposure.
This tutorial assumes a few things. Firstly, you know what I mean by multiple exposures. Secondly, your images were shot on a tripod and therefore aligned correctly. And finally, you have an understanding of masking in Photoshop.
Step 1. Find two exposures
To follow along with this tutorial, please find two exposures, one which is normally exposed, and a darker one which has compensated for any overexposed highlights. If you don't have any, you can download my exposures from this link:
Step 2. Layer those two exposures in Photoshop
In Photoshop, go to File > Open and locate those two exposures. They will open up in separate windows. To layer them, you just need to go to one of the windows, press Ctrl+A (CMD+A on a Mac), which will select the whole image. Then press Ctrl+C (CMD+C on a Mac) to copy this selection to your clipboard.
Now click on the other open window where the other exposure is sitting and simply press Ctrl+V (CMD+V on Mac) to paste this selection. You will now have the two exposures as layers. Feel free to close the other open window.
Alternatively you can open the folder that contains the two images in Adobe Bridge and go to; Tools > Photoshop > Load Files into Photoshop Layers.
Step 3. Placement of layers
In your Layers panel, you will see both of your exposures. Drag the normally exposed image to the bottom, if it isn't there already. So now the darker exposure should be on top.
The reason for doing this is because you are blending the darker exposure into your brighter exposure. So your brighter exposure is acting as the base exposure. The base exposure is your main image which contains most of the image information. You always want your base exposure at the bottom.
Step 4. Add a white mask to the dark exposure
Select the dark exposure, and press the little add a mask icon at the bottom of the layers panel.
Step 5. Make the darker exposure invisible
Whenever you want to blend a darker exposure into a base (lighter) exposure, it is wise to make the darker exposure invisible before the actual exposure blending process. Explaining why you want to do this goes into slightly more advanced notions of exposure blending, nevertheless, it is important to know.
Making the right mask
Soon you are going to build a mask that will target the highlights in your image. The mask will look something like this:
Notice how the highlights are quite bright on the mask, while the midtones and shadows are quite dark. This means that you have created a mask that will affect those highlighted areas, and have minimal effect on the darker tones. Whatever is white or very light grey in your mask is selected, and all darker tones are less selected. Anything that is black on the mask is completely unaffected.
The reason why you create the mask above is that those highlights are really bright in your base exposure. And that is the exposure which you asked Photoshop to build your mask around. So creating a mask that also makes those areas bright was quite easy since they're already bright in the base exposure.
However, if you built the mask around your dark exposure, those areas aren't as well selected as the previous mask. This is what you get.
The affected areas are now much smaller in the mask you created around your darker exposure. This is because you are building a mask to select the brighter areas of an image. Since there aren't many bright areas in your darker exposure, the mask created around that exposure also doesn't contain a large selection of highlights. Sometimes this darker mask will work, but often it doesn't. Building a mask around the base exposure is usually better.
Even if you don't understand any of this, please just remember, as a useful rule, make your darker exposure invisible when it comes to exposure blending.
Step 6. Creating the mask
The method of exposure blending that you are about to use is called Apply Image. In this technique, Photoshop will read the image you see on the big screen in front of you, which should be your base exposure (because the dark exposure is invisible), it will translate that image into greyscale, and then apply it to the mask that you created on the darker exposure.
To do this, select the darker exposure (but keep it invisible), and now select the mask of that exposure. In other words, just click directly on the mask in the layers panel and it will become active.
Now go to the top menu called Image, then down to Apply Image. A pop-up box will appear. Please make sure your pop-up settings are the same as mine. If you look over at the mask on the darker exposure, you will see that it now has a black and white version of your image on it.
Press OK to apply the mask.
Step 7. Refining the mask
If you toggle the visibility of the darker exposure on and off, you will see that mask you generated has now essentially blended the two exposures. But you may also notice that it doesn't look great. Most of the base exposure, when you make the darker exposure visible, is being affected. But you just want to affect the highlights.
This is happening because your mask is not contrasty enough. In other words, you need to make your highlights brighter in the mask, and your midtones and shadows darker.
Here is what your mask looks like right now.
To view your mask, hold down Alt (Option on Mac) and left-click on the mask of the darker exposure. You should now see the mask full size. To go back to your normal view, do exactly the same thing. You should now see your normal, color image.
So how do you make the mask have more contrast? Well, that is extremely easy. There are a few ways to do this but you are going to do it the easy way. Make the darker exposure invisible again, and with the mask selected, just as before, go back to Image > Apply Image, and when the pop-up appears, just press OK.
This is what your new mask should look like.
Now make the darker exposure visible again and look at the mask (Alt/Option and left-click the mask). Do you see how it is more contrasty now? The shadows and midtones are darker, while the highlights have become more targeted. So if you deselect the mask and toggle the visibility of the darker exposure on and off, you'll notice that the changes have become much more targeted towards the highlights, and affect less of the shadows and midtones.
If you want to create an even more targeted mask, you can repeat the Apply Image again, as many times as you like. Each time you will be creating a mask that targets the highlights more.
However, this is very important to remember, when exposure blending, you do not want a mask that has too much contrast. You want the blend between the exposures to be smooth and natural. So if you are unsure, try to go for a slightly less contrasty/restrictive mask. But feel free to play around with it. Make your mask more and more targeted and see how it affects your image.
For this example image, using Apply Image twice works well.
Step 8. Final touches
The final step in this basic tutorial is to lower the opacity of the darker exposure. If you are blending a dark sky from a darker exposure, for example, into a normally exposed image, it might look strange. The sky should usually be brighter during the day than foreground elements. In order to make the blend more natural, you may need to select the darker exposure layer, and just bring the opacity of that layer down until it looks natural.
For this image, use an opacity of 50% on the dark exposure layer. Below is the final blend. Note that I haven't added any contrast or any other post-processing. These exposures are straight from RAW files so they will look flat. But now the highlights have been naturally recovered.
Apply Image is just one of a few superb ways you can naturally blend exposures in Photoshop. If you're curious to see more, feel free to watch my video, 5 Ways to Blend Exposures below.
If you want to learn more about luminosity masking and go to the next level, you might want to check out my course The Art of Digital Blending (only $44.99).
Named as one of the top photographers on 500px.com by Fstoppers.com, and Followed by more than 250,000 photographers, Jimmy McIntyre is a travel photographer and educator. Jimmy has had the incredible pleasure of shooting amazing spots all over the world and teaching photography on 4 different continents. He is also the creator of Raya Pro, a famous exposure blending panel for Photoshop used by thousands of photographers.