Tutorial: Using Black & White points in Photoshop to clear up an underexposed picture
Filed Under (Photography, Photoshop, Portfolio, Tutorial) by lhodsdon on 12-06-2008
Tagged Under : Design, Kristen, Luke, Photography, Photoshop, Portfolio, Tutorial
At my current day to day job I use this technique religiously. It’s fast, easy and extremely effective when trying to achieve better quality photos for print and online. In the following Adobe Photoshop tutorial I’ll walk you though a quick (less than a minute once you learn the steps) process on how to brighten up those dull, dark photos you’ve been sent from your clients… or in my case, taken with your poor digital camera.
The following tutorial was done in Adobe Photoshop CS3, but 80% of the process can be used on just about any program with a “Levels” function (such as the freeware, open source image editing software, GIMP) while the last 20% can be done all the way back to Photoshop CS1 (this is the black overlay feature achieved by holding the ‘option’ or ‘alt’ key in levels).
Step 1:
Open the file you wish to adjust and open the Levels adjustment window . This will bring up your image’s histogram and the palette where this tutorial will focus. Locate the white point slider as seen above.
Step 2:
One of the best features of this tutorial is built right in to Photoshop CS1+. While on the white point slider, press and hold and begin scrubbing the bar left and right. This will give you a black overlay over your image. If you’re using an older version of Photoshop or a different program you can skip to step 4.
Step 3:
While still holding , scrub your white point slider to the left on the histogram. The key here is to slide the white point until your overlay image starts to get to a point where it turns pure white. This is where we will be setting the white point of your image, thus adjusting the entire histogram to account for the new white point of the image.
Step 4:
Now that we’ve found the new area of the image we want to set our white point, we have to actually do it. Locate the tool, as seen above, and click it once to highlight. Your cursor should now change to the little Eyedropper icon (Depending on how you have your preferences set up in Photoshop, this may or may not happen.). Take the White Point Eyedropper and find the area of the image we designated to be our new white point, click once. You should see an immediate change to your image and a new histogram should be generated in your Levels window as well. If the desired change is too much, or too strong, you can keep clicking around until you get a nice new balance for your white point.
Step 5:
Now we will repeat steps 2-4 above, but on the opposite side of the histogram, the black point. Again, we will hold the and scrub our black point slider on the histogram, but this time we will be looking for the image to turn it’s blackest.
Step 6:
Now that we’ve found our new black point we will follow the same process as step 4, but using the . Locate the Black Point Eyedropper and click once to highlight it. Now, find the area we designated to be our new black point on our image, and click once. Again, if the desired effect is too much, or too strong, try clicking around to find a more suitable black point. Once you click you should again see an immediate change in your image and a new histogram should be generated.
Step 7:
Lastly, review the changes you’ve made and adjust the slider bars to tweak your image to get it just where you want it. The final result should be a much brighter, more vibrant picture.
