How to preview and control histogram clipping in Lightroom

There’s this idea in digital photography that your histogram must never be clipped, and that it should always fit – just – within the maximum width of the scale. And sometimes we work so hard to recover shadow and highlight detail to prevent clipping, that we end up with an image that has lost its impact.

So here’s a more controversial approach! The fact is that some shadow areas in your photographs can be clipped and might even look better as a result. Similarly, some highlights (particularly ‘specular’ highlights off waves, for example, or polished surfaces) will never come back no matter what you do, so it’s silly to compromise the look of the image by trying to get them back regardless.

Here’s an example. These frost-crusted blackberry leaves in autumn were strikingly colourful, but while the captured image looks OK, there’s just more tonal range from shadows to highlights than we actually need.

01 The image histogram

A glance at the histogram in Lightroom’s Develop module shows the problem. You’ll see the histogram tails off before it reaches the far left-hand side of the scale, which means the image has no solid black tones. This means in turn that its contrast isn’t as strong as it could be.

02 Conventional shadow adjustment

Now the ‘correct’ thing to do at this point according to current digital theory is to adjust the Blacks slider so that the end of the histogram moves to the left end of the scale – but no further. Can you see the difference in the picture? It’s not much, is it?

03 Clipping preview

There’s a great trick you can use here and in other Adobe applications when you’re adjusting levels. If you hold down the alt key as you drag the slider, you’ll see only those areas which are being clipped.

If I try this now, I can see that only a few tiny outlines are affected in the top right corner of the image. The different colours indicate which colour channels are being clipped. This clipping affects the colours and saturation, but detail is still visible – it’s only where the preview shows solid black that indicates solid black areas in the picture.

My conservative, histogram-based approach hasn’t degraded the picture’s tonal range, but it hasn’t turned it into a better picture, either.

04 Knowing what to clip

The point is, does clipping really matter? On some images it might, but on others there may be areas of the picture which can be clipped without harming the picture at all. If you just use the histogram, you may never find out, but in this preview mode you get a much better sense of what you can get away with.

That’s why I’ve chosen this picture. If I drag the Blacks slider far over to the left, I can see that a large area to the right of the picture turns black. But this is simply an iron post in the background that’s got nothing to do with the main subject – the frosty leaves. This post takes up a big chunk of the histogram, but it has no pictorial value.

Indeed, clipping it so heavily could be a good thing – by removing the detail, I could be removing a distraction too.

05 The finished picture

And that’s what I call a result! I don’t mind the fact that the post on the right is now a solid black – its ugly, rusty surface wasn’t the point of the picture anyway. But just look at the effect of this adjustment on the colours and the definition in the rest of the picture – brilliant!