Lightroom 2 Raw Development: Exposure

Last time in my ongoing ramblings on Lightroom 2 raw workflow, I focused on white balance. Today we move along a bit further with some elements of exposure.

A note about workflow seems pertinent: Lightroom’s preset abilities are pretty extensive, but I don’t make a whole lot of use of them, particularly for raw development (Though I do have lots of metadata presets that I apply at import to apply information about location). The develop presets make the most sense to me for repeated, reliable situations: Shooting in a studio, for example, where you know combinations of lens and light and in which case the effort to tune and save those presets will be rewarded. That’s my experience so far, so I’ve neglected to spend much time working with develop presets.

So let’s talk about exposure. Lightroom provides an exposure histogram in the upper right pane. The histogram quantifies the amount of light found between black, at the left end, and white, at the right side of the plot. A histogram with nothing but a steep peak at the right end will likely appear washed out or overexposed; likewise, a plot with nothing but a peak at the far left will be dark, lacking highlights.

Lightroom 2 histogram screenshot

Here’s what this particular histogram is telling us:

  • In its histogram display, Lightroom provides some basic image information: ISO, focal length, aperture, and shutter speed.
  • We have light basically all throughout the plot’s range, with a particular peak close to the bright end.
  • Overall, the exposure of this image isn’t bad. We can adjust exposure either with the exposure slider or by grabbing and dragging the center portion of the histogram left or right to obtain the kind of effect we want to get. I tend to boost exposure a bit when working up my photos —- but be careful when sliding exposure rightward: too much will add speckly noise to the image.
  • The filled triangles at the upper left and right corners are clipping indicators; since they’re filled, it means that this image has some amount of both cut off highlights (right end of histogram: “blown highlights”) and clipped darks (left end of histogram). That is, some detail is lost in the brightest and darkest areas of the photos. The more clipping, the brighter the fill of the triangles. You can see the clipping in the histogram as the blue peak pressed up against the left edge, and the grey/red smooshed into the right end. To see just what’s lost, hit J. The blue and red superimposed over the image represent lost darks and lights, respectively.

Here’s a sample image. On the right is an illustration of the highlight clipping revealed by hitting J in the develop module:

Lightroom 2 sample image Lightroom 2 sample image

To bring a bit more detail back into this image, especially some of the texture in that yukon gold, you use the “recover” slider in the develop pane, or simply drag the rightmost edge of the histogram back toward the left side: hover the mouse along different parts of the histogram to identify the various draggable regions. As you increase the “recovery” value or drag that right end leftward, you’ll see the red blown highlights indications start to fade, as in the image below where the recovery slider has been pegged all the way rightward:

Lightroom 2 sample image Lightroom 2 sample image

Adjust per taste. See how much more gray the background of this image has become by pegging the recovery? Lightroom can often recover a ton of detail in highlights, but at the extreme end the cost will be a dimming of the overall image.

The same goes for darks: You can bring detail back out of a black swatch of image by reducing the “blacks” slider or by dragging the leftmost end of the histogram back to the right a bit. I often find it works nicely to drag that histogram until the leftmost slope of the dark end of the plot rests just at the edge of the display — that is, where you’ve just barely recovered all the clipped dark areas.

While measurements of light and dark can be quantified in the histogram, appreciation of light and dark are subjective. Leaving blown highlights (or intentionally blowing them by increasing the exposure — grab the middle of that histogram and pull it rightwards until you see something you like) and lost black regions of an image may help convey exactly what you want an image to do.

One more exposure-related tip: Fill light. Use this slider (or, as always, slide the histogram itself — the fill light region is just shy of the leftmost “darks” region of the plot) to bring up the light in the image’s shadowy regions without boosting the overall exposure. This can do wonders for errant shadows across a face.

Be watchful for new noise when you add fill light, and it’s a good idea to bump up the “clarity“ slider in conjunction with fill light, since fill light tends to take a bit of the punch out of the image.

So, there’s a quick take on adjusting exposure with Lightroom 2. Between white balance and exposure, you have the core set of adjustments to your raw images covered, but there’s more to come: Further tuning involves sharpening, noise reduction, and crops, as well as other adjustments we might make to color. Some discussion of those are coming up in my next installment of Lightroom for the Rest of Us (or whatever it is I’ll be calling this series by then).