It happens to the best of us.
When we see something that we think will make a great photo, we pull out our digital camera and find that that great photo is seriously underexposed? If you have Photoshop, there are several quick fixes available to you. Best of all, you don’t have to be a certified Photoshop master to get acceptable results. In fact, Photoshop Wizards master these tricks before earning their Wizard robes.
For the average person looking to “fix” that great family barbecue picture, it all comes down to knowing where to look.
In this tutorial, we’ll use four different methods to work with an overexposed image. They are:
Correct the exposure using the Exposure menu.
Use brightness and contrast.
Understand how to read a histogram in levels.
Use adjustment layers and blending modes.
- Technique 1: Using the Exposure Menu to Correct an Image
- Technique 2: Using the Brightness and Contrast Controls
- Technique 3: How to use levels
- Technique 4: Using an adjustment layer and blending modes
Technique 1: Using the Exposure Menu to Correct an Image
A possible solution is to use the menu exhibition is located in the section Image > Settings > Exposure † While the dialog may seem a bit cryptic, it actually covers three main areas of image correction: white point, black point, midtones, or gamma. In this dialog they do:
- exhibition † Adjusts highlights (white point) and ignores everything else.
- Prejudice † Adjusts shadows (black dot) and ignores everything else.
- Gamma correction : Adjust midtones and ignore everything else.
What you don’t do is pull the slider. Instead, you use one of the pipettes – black, medium, white – to “sample” the color. By this we mean that the eyedropper shifts any highlights, midtones, or shadows to the pixel you clicked.
In this image, we chose the white eyedropper color because the image was dark and non-glare when underexposed. Then we clicked on the white cloud in the back of the tree,
So how does a pipette work? Generally, when you click on a white pixel, the eyedropper looks at 5 pixels, finds the average white for those pixels, and sets that as the basis for the white in the image.
When using this technique, don’t look for a pure white pixel. Look for something, for example this cloud, “off white”.
Exposure is also available as an adjustment layer, which allows you to “tweak” settings rather than a menu.
Technique 2: Using the Brightness and Contrast Controls
If the image is dark, it may just need to be lit. Sometimes this is all you can do, and as you will see, this can indeed be a mistake. For starters, we opened Image > Settings > Brightness/Contrast †
The dialog box that opens has two sliders: one for Brightness and the other for Contrast † There is also an Auto button. Should be avoided as the result is inconsistent. Instead, use your eyes to determine an acceptable result.
Move the slider to make the image brighter Brightness to the right. To make it darker, move the slider in the other direction. In the case of this image, we’ve moved the brightness slider to the right.
Also note when increasing the brightness: Contrast † These two go together. If you turn up the brightness, try lowering the contrast to bring out some more detail in the image.
Brightness / Contrast also available as adjustment layer which allows you to “customize” settings instead of a menu.
Technique 3: How to use levels
The third method will help you get rid of grainy weeds and give you a couple of ways to spice up an image.
For starters, we opened the menu Levels † When the dialog box opens, you will see a graph called a histogram and three pipettes.
A histogram shows the distribution of tones in an image. A large histogram resembles a bell curve. In the case of this image, the graph is shifted to the left – black – and there seems to be nothing between the halftone slider in the center and the white slider on the right. This is a classic example of an underexposed histogram.
There are two ways to brighten an image.
Drag first white slider to the left, where there appear to be some tones in the histogram. As you move the white slider, the midtone slider also moves to the left. So what’s going on? Again, in the most general terms, you’re telling Photoshop that all the pixels between white and midtone — from 126 to 255 — now have a value of 255, which now makes the pixels involved brighter. The result is a clearer image.
Another way is to press the button parameters: in the dialog box Levels † A dialog box will open Car Color correction options † The four options affect the image in different ways, and the histogram also changes when you select an option. In this case, we chose Find dark and light colors that really bring out the details of the image.
The levels are also available as an adjustment layer that allows you to “customize” options instead of a menu. The Levels adjustment layer does not contain color adjustment options.
Technique 4: Using an adjustment layer and blending modes
You may have noticed that all three methods mentioned earlier use an adjustment layer. Think of an adjustment layer as a way to “adjust” your settings when something isn’t right.
So far in this tutorial, everything you’ve done has essentially been saved. There is no way to go back if you are not ready to return the image to its original state. The three previous methods are considered “destructive” in the sense that any change you make is permanent.
Remember that histogram from the previous technique? A good histogram is a solid color. Apply one of the three techniques presented, open the levels and you will see a completely different histogram. It looks like it has holes in it, or as we like to say, “looks like a fence”.
These holes represent information about an image that has been discarded and will never be recovered. Keep adjusting the image and the histogram will become more even, even though the image may look good. This is a classic case of destructive editing.
The adjustment layer is called “Non-destructive” because the change is applied by the layer and not directly to the image. If you don’t want a layer, delete it and the influence on the main image will be removed. Do you want to change the setting? Click on layer Amendment and make changes. It’s that simple.
In this case we pressed the button Adjustment Layer at the bottom of the layer panels and in the pop-up menu that appears, choose Levels † A new adjustment layer appears above the background layer. The histogram also appears in the Properties panel and we can adjust the white point by moving the slider or clicking on an off-white pixel in the image to set the white point. In this case, we won’t do either. Instead we choose Screen Overlay Mode and when we release the mouse, the image becomes brighter and more details appear. What happened?
Blending modes essentially apply some heavy math to the pixels in an image. With Screen, everything on the pure black layer disappears from view. How it works, in general, all “brightness” values in an image are averaged and the result is applied to all pixels in the image. Everything that is pure white remains unchanged and every shade of gray between pure black and pure white becomes lighter.
For bonus points you can improve the image even further.
Duplicate the adjustment layer and decrease the opacity of the layer instead of changing the blending mode. To do this, you need to “return” the brightness and increase the details of the image.