Learn the ultimate Photoshop technique to brighten underexposed pictures. In this Photoshop tutorial, you will learn how to use a masking technique to brighten images without overexposing highlights. This Photoshop technique can also be used to darken images without affecting the highlights.
Sample PSD (Photoshop Document)
Analyzing the Methods
To begin this Photoshop tutorial, open an image that is underexposed. If you don’t have any underexposed photos, then you must be a very good photographer! Just kidding – you can acquire underexposed images by searching “underexposed” on Google Images.
Now, let’s experiment with the common brightening methods to see how they perform.
First, let’s use the Brightness/Contrast tool as it is the most simple tool to increase brightness. Choose Image > Adjustment > Brightness/Contrast. Increase the contrast so that the exposure is correct.
If you’re using Photoshop CS2, the results should be quite horrible. In Photoshop CS3, the Brightness/Contrast tool has greatly improved results. But no matter which version of Photoshop you use, you’ll notice that the areas that are the correct exposure got brighter; making them overexposed. This is a common problem with brightening images. Don’t click OK; click cancel. If you did, press Ctrl+Z to undo.
The Levels tool is one of the better ways brighten an image. Load up the Levels tool (Image > Adjustments > Levels). The levels may look daunting, but it is actually easy to use; just slightly harder than the Brightness/Contrast tool.
To increase the brightness with the Levels tool, drag the gray input slider towards the left. If you want to add more contrast, drag the white input slider towards the left. The results are much better than the Brightness/Contrast tool, but the highlights are still being brightened.
You can play around with the Output Levels settings to filter which areas are affected, but that creates posterization in your image – yuck!
The Levels tool may do a good job brightening an image, but it’s not the best. Click Cancel to exit out of the Levels tool.
If you’re a Photoshop expert, you probably would have guessed what I’ll be talking about next – the Curves tool. The Curves tool offers more flexibility than the Levels, but it still affects the highlights. I think you get the point already, but some people would ask, “What about the Shadows/Highlights Tool?”.
The Shadows/Highlights tool can brighten an image only in the shadows – like it says – and it can work quite well, but if you use any setting above 50%, you can start to see halos and overly detailed shadows. Open the Shadows/Highlights tool (Image > Adjustments > Shadows/Highlights) and try it yourself. You should try the Shadows/Highlights first, but if that doesn’t work, don’t worry because we have a secret technique up our sleeves that we’re about to reveal.
Brighten Photos Like a Pro Photoshop Tutorial
Hopefully you didn’t apply any of those brightening methods shown previously. If you did, just undo all the way back until you get to the unedited image.
First, we’ll add a Levels adjustment layer to brighten the image. You may also use a Curves adjustment layer if you know how to adjust the settings.
In the Levels tool, move the gray input slider towards the left to brighten the image. If you want to increase contrast, move the white input slider towards the left.
Click OK when you’re done. You should now have a new adjustment layer in your Layers palette.
Here’s the key to this Photoshop brightening technique – the Apply Image tool. Choose Image > Apply Image. With the Apply Image tool, use the settings below and click OK. What this will do is apply an inverted copy of the image to the layer mask that we have selected..
So what exactly happened?
To understand this, you’ll need to understand layer masks. A layer mask works like a stencil. Anything black in the layer mask means that it is transparent and anything white in the image means that it’s visible. If it’s gray, it’s translucent
What we just did was made the adjustment layer only affect the image based on its brightness. That means that bright areas will be less affected than the dark areas. We just brightened the image without overexposing the highlights and created an image with a more visible dynamic range.
The image should look like it has lower contrast and higher saturation. If you want to increase the contrast, add a Brightness/Contrast adjustment layer. If you’re using Photoshop CS2 or older, use the Levels tool instead because the Brightness/Contrast tool in Photoshop CS2 and older produce poor quality results.
With the Brightness/Contrast tool, simply increase the contrast until you get the contrast level that you desire.To increase the contrast with the Levels tool, move the black and white input slider towards the center.
The image should look naturally more vivid. If you want to restore the original saturation, here’s a simple three-step technique to restore the original saturation.
- Duplicate the background layer.
- Move the duplicated layer to the top.
- Change the blending mode to Saturation. You can adjust the opacity to bring back some of the saturation.
Darkening the Image
This technique can also be used to effectively darken images. Simply do the reverse:
- With the Levels tool, darken the image instead of brightening.
- When using the Apply Image tool, leave the Invert option unchecked.
Below is a comparison of the original image and the two brightening methods. Using just the levels to brighten the image, the clouds in the background almost disappeared. With the Photoshop technique shown in this tutorial, the sky has brightened slightly but the clouds are still visible.