Previously, I wrote about the meaning of the term “exposure” in camera talk. To briefly recap, a “stop” is a relative term describing how well-lit and well-exposed the image is. Adjusting the camera settings to increase the light by “one stop” will effectively double the amount of light in the picture (either by opening the aperture, raising the ISO, or lowering the shutter speed).

The same terminology applies in post-processing, although at this point you’re no longer changing the camera settings. In photo editing software, including Adobe Lightroom, you will usually find an “Exposure” adjustment or slider. Dragging this will digitally alter the image and brighten or darken it as if you had adjusted the camera settings.

An Example – A Test Shot of Joel

Here’s an example from a shoot I did a few weeks ago. The original image was a test shot, one of the first frames I took in the afternoon. We were outside at Branch Brook Park, and it was pretty sunny out. So I was trying to pin down the ambient lighting conditions and then I was going to bring in one or two lights to fill things out.

This first image is clearly under-exposed, although not by a ton. It’s a little dark, and everything kind of melds together into shadow. For the second image, I simply imported the photo into Lightroom and dragged the Exposure slider to the right (to +1.00 – one full stop). Now the image is much closer to being well-exposed. It could probably use a little tweaking, but it’s close enough. Some other adjustments could help the image, too, but in general it falls a bit flat because it was taken in a shady area without any additional accent lights.

In the third image, I continued to drag the Exposure slider and it now rests at +2.00 (two full stops). At this point, it’s beginning to look over-exposed. The skin is getting a little white-ish and the cloth wrap is near to getting blown out. Too far! You’ve gotta be careful when dragging the exposure slider that you don’t over-do it, because you will eventually blow out the whites in the picture. Conversely, if you drag it too far to the left, you’ll black out the shadows.

So When Do I Use It?

The exposure slider is a pretty standard go-to tool. You shouldn’t have to make huge adjustments with it, but a lot of images (especially those taken under changing lighting conditions) can use a little tweak – about a third of a stop to two thirds of a stop. If you find yourself adjusting the exposure by more than a full stop, chances are you have the camera settings wrong and you should have changed that when you had the chance.

The effectiveness of the exposure slider also depends somewhat on how you capture the pictures. If you store them in JPGs, then you’ll create a lot more noise as Lightroom artificially brightens or darkens the image. If you captured your pictures in a RAW format, then there’s already a greater range of light information stored in the file than your screen can display. You can safely move the slider up and down by one or two stops without damaging the photo. In this case (and in most), RAW gives you more flexibility in post-processing to utilize all of the information captured by your cameras sensor.