Basic black and white adjustments in your digital darkroom

Black and white images are rarely perfect straight from the camera. If you’ve ever used your camera’s black and white modes hoping for some magical monochrome transformation, you’ll probably have come away disappointed. Black and white imagery relies on light and contrast… and a degree of exaggeration. Sometimes real-world scenes don’t provide the tonal depth and drama that a black and white rendering needs, and very often images will only come alive in the darkroom, or in its modern digital replacement, your image editor.

• Other articles in this black and white series
• Why photograph in black and white?
• How to shoot in black and white
• What are the best cameras for black and white photography?
• Converting color photographs to black and white: what’s the best method to use?
• Basic black and white adjustments in your digital darkroom
• Dodging and burning techniques, a key part of black and white imagery

This isn’t new. Black and white negatives don’t always have the impact you are looking for straight from the camera (or the developing tank). Developing the film is only the first part – it’s how you make the print that finishes the process.

Now there are some very sophisticated adjustments you can make in black and white using software, but let’s start with some basics. Here are a two standard adjustments you might want to make before you do anything else.

• Brightness (or print exposure time): In the darkroom you would adjust the length of the exposure of the print under the enlarger to do this. In software, this can be achieved with Brightness or Exposure sliders
• Contrast, or ‘paper grade’: Darkroom print experts would keep boxes of paper in different contrast ‘grades’ to cope with excessively flat or contrasty negatives. With digital editing, contrast is much easier to manage with Levels and Curves adjustments

In fact, Levels and Curves adjustments are so effective that they can take care of overall exposure and brightness at the same time. Alternatively, you can fix the contrast first and then adjust the brightness or exposure with separate sliders, if that makes more sense to you.

So let’s take a look at Levels and Curves to see why they are different and when you might choose one over the other.

Levels adjustments: simple and direct

Levels adjustments are the digital equivalent of changing paper grades when printing, with the advantage that you can see ‘live’ what kind of contrast adjustments you need without having to expose and develop a print first. There’s no need for test strips in the digital darkroom!

Generally, photographers like to create black and white images with a full range of tones from a solid black to a brilliant white and, depending on the scene and the camera exposure, you might not always get this straight from the camera.

The best tool for checking is the histogram. The camera will probably display a histogram if you know how to enable this option, but your photo editing software certainly will, and will also offer the tools to maximize the brightness range too.

You may find your software’s histogram display in a separate panel, or in the Levels or Curves adjustment tools. Levels adjustments are the most straightforward way to maximize tonal range. What you’re looking for is an image histogram that extends right from the left end (shadows) of the scale to the right end (highlights). If there’s a gap between the ‘head’ or ‘tail’ of the histogram and the end of the scale, it means the image tones do not go all the way to a solid black or a brilliant white. To fix this, you can move the black point and white point sliders underneath the scale to line up with the start and the end of the histogram shape. This makes sure that the darkest tones in the image correspond to a solid black and the lightest tones are rendered as bright white.

Just a quick note: don’t be a slave to the histogram. In black and white you can often afford to clip some shadow and highlight detail to improve the overall impact of the image. The histogram is simply there to tell you what’s happening, not to tell you what to do!

Levels adjustments are a simple way to check and maximize the tonal range of your black and white images and a great way to extend the tonal range of low contrast or flat looking images.

Sometimes you have a different problem, and your photo has ‘clipped’ shadows or highlights. In other words the histogram is abruptly cut off at the shadow or highlight end of the scale. This means that large areas of the photo will be rendered as a solid black or a blown-out white.

Now if you’ve shot JPEG images with the camera, then this clipped shadow or highlight detail is lost for good and you just have to make the best of it. But if you’re working with RAW files then you have a little more leeway.

That’s because RAW files contain extended shadow and highlight detail that you don’t see straight away but which can be recovered by good RAW processing software by adjusting the exposure value or dedicated shadows and highlights sliders. I generally find you can recover around 1EV of highlight detail from RAW files but sometimes 3-4EV of shadow detail. With black and white, where you’re often carrying out strong tonal adjustments, I would always recommend shooting RAW files for this reason.

Levels adjustments can do more than simply maximise the contrast range, because they can also be used for overall brightness or exposure adjustment. You’ll see that as well as black point and white point sliders, Levels dialogs also have a mid-point slider. You can drag this to the left or the right to change the brightness of the image without altering its overall tonal range.

Curves adjustments: targeted contrast adjustments

You can use levels adjustments to optimize the tonal range of your black and white photos before you do any other editing work, but photo editing software will usually offer curves adjustments for modifying the contrast.

Just to complicate things (or make them easier?), some programs roll levels and curves together into a single adjustment, so that in Lightroom Classic you can use the Tone Curve panel both to set the black and white points for the image (just like Levels) and to change the curve shape too.

The way to understand how levels and curves work together is to imagine that levels adjustments are used to control the overall tonal range of the photo but curves are used to modify the contrast WITHIN that tonal range. 

For example, by changing the shape of the curve, you can add contrast to the midtones of a photo without clipping the shadow or highlight detail. This is done with an ‘S’-shape curve which is steeper in the middle of the tonal range but flattens out in the shadow or highlight areas. With curves, the steeper the curve, the higher the contrast within that tonal range. 

You can use different curve shapes to add more contrast to the shadows, for example, or to the highlights. This is done using control points you add to the curve and then move up and down, or sometimes with sliders labelled ‘shadows’, ‘darks’, ‘lights’ and ‘highlights’, for example.

The key thing to remember about curves is that the overall tonal range remains the same. If you increase the contrast in one part of the tonal range you lose it somewhere else. The trick is to adjust the shape of the curve to add contrast where you need it and sacrifice contrast where it’s not going to show.

Between them, levels and curves adjustments achieve the same thing as changing film development time to increase or reduce its contrast, and using different paper grades and exposure times under the enlarger.

But photo-editing software offers another control that can really add punch to black and white images – clarity.

Dynamic range adjustments: Shadows and Highlights

This is something you could never really do in the darkroom except perhaps with some complicated chemical processes, but is quite easy in an image editor – though really you need to be working with RAW files and their extended tonal range compared to JPEGs.

Typically you will get a Shadows slider, which will lighten darker tones but leave the midtones and highlights unaffected, and a Highlights slider for recovering ‘blown’ highlights without affecting the overall image exposure. These can be extremely useful, especially in black and white, which thrives on high brightness ranges.

Some photo editors, including Lightroom Classic and Capture One, offer automatic adjustments to a number of different parameters, including highlight and shadow recovery with RAW files. These can restore contrast to flat-looking images, or restore clipped shadow or highlight detail to high contrast scenes. But they can also flatten out the drama in black and white shots and are designed to optimize images according to a set of algorithms, not necessarily to your own creative taste. Try them out as a starting point by all means, but don’t assume their rendering is better or more ‘correct’ than your own manual adjustments.

Clarity adjustments: adding ‘punch’ to black and white

Clarity adjustments work by increasing the contrast around object outlines to make them stand out more. It’s rather like sharpening, but on a much wider, softer scale. It can help objects stand out much better in flat and boring lighting and can enhance the strong, dramatic contrasts associated with black and white photography.

Indeed, many cameras now incorporate an optional clarity adjustment with their in-built picture styles. Remember, though, that this in-camera processing applies only to JPEG images – if you shoot RAW files these will be ignored and you will need to apply clarity and other adjustments in software later.

So these are three adjustments you might want to carry out on your black and white photos right from the start. But these affect the whole image, and very often you’ll want to enhance individual objects and areas only.

We can call these overall adjustments ‘global’ adjustments, and we can call any enhancements to specific areas ‘local’ adjustments, which is equivalent to the black and white darkroom technique of ‘dodging and burning’, and that’s a separate topic.