How to Rescue Under-Exposed JPEG Images with Adobe Photoshop

In an ideal world, we would have beautiful, correctly exposed RAW images to work with all the time. What we have in reality, for a variety of reasons, is often an incorrectly exposed JPEG. In this tutorial you'll learn how to bring some lost detail back into an under-exposed JPEG image using Adobe Photoshop.

The Challenge of JPEG Images

There are many situations where you might have to work with a less-than-ideal JPEG image.

I advise always shooting in RAW when you can but sometimes
that isn'tan option. Most cell phone cameras, for example, only record photos in JPEG. If you areshooting in JPEG format, for whatever reason, then sometimes you might end up with a photograph that’s disappointing.

You might also be given a JPEG when working on a project with others. In this case you just have to make do with the image supplied.

Beware that not all JPEGs are recoverable. JPEG is a great format because it allows us to compress a tremendous amount of image data into a relatively small file size, but unfortunately this space saving comes at the cost of flexibility.

1. Assess the Image

Here is the example image I'll work through in this tutorial:

This scene is very high contrast. The windows behind the two men are nearly white, and the bench area is in deep shadow. To a camera's light meter, this scene is correctly exposed: there is an equal amount of light and dark in the photograph on average.

To the human eye, however, it's the two figures (especially their faces) that matter most in the composition. In this example we want to recover some detail from the shadow areas to create an image that includes a more complete image of the two figures.

2. Create Levels Adjustment Layer and Adjust Sliders to Brighten Image

Open up your image file in Photoshop and create a Levels Adjustment Layer as shown below:

Drag the sliders to brighten up the image. You’ll probably
only need to adjust the grey middle slider (the midtones) and drag it to the right to see an improvement.

In very dark images you may need to adjust both the midtones and and the shadows. To lighten the shadows, pull the black slider from the left towards the centre.

3. Selectively Mask the Levels Adjustment Layer

You’ll notice now that as the change has been applied
to the whole picture certain elements become too bright. Have no fear. When you created the
adjustment layer it also created a Layer Mask, and we’re going to use it now:

1. Select the Brush tool (B) from the toolbar
   
2. Reset the palette back to default (D) with black as the primary colour (X to switch)
   
3. Set theBrush to 0% Hardness (this creates a soft edged brush) and an appropraite Size for the area you are working on
   
4. Reduce theBrush to 20% Opacity (Control-2)
   
5. Click on the Layer Maskicon on the adjustment layer
   
6. Start
   to brush over the highlight areas in the image that are blown out

You should start to see the return of some detail you lost
when you added your levels layer. If you make a mistake, simply change the brush
colour to white (X) and brush over the area again. For more aggressive control, set the Brush Opacity to a higher percentage.

4. Restore Colour With Vibrance Adjustment Layer

Next we’re going to add a bit of colour back to those blown
out areas. Create a new Adjustment Layer, this time Vibrance.

Drag the Vibrance slider up until you see colour come back
to the bleached out parts of your photo but not so much that it starts to look
over-saturated.

5. Restore Contrast With Curves Adjustment Layer

If your picture still has a bleached look, like my example
does, create a Curves Adjustment Layer. Use points to create a reverse ‘S’ shape as shown
below to add some contrast back to the image.

6. Fine-Tune Adjustment Layers

Once you have all your adjustment layers created you can adjust the Opacity of each layer to fine-tune the balance of your work for the final image. Select the layer you want to adjust, then move theOpacity slider up or down as desired. For fine control, you can also key in a desired percentage.

Conclusion

There you have it, our rescued JPEG! As I mentioned in the introduction, it's worth photographing in RAW if you can if that is an option. There's much more information to recover from a RAW, which retains all the data from the camera's sensor, than a JPEG; a compressed version of the data. Hopefully this quick tutorial will help you if you find you've taken a JPEG only to find it under or over exposed.