Black and white photography: Basic processing

If you shoot RAW, you have the advantage of greater latitude when it comes to editing your shots. This is because of the higher bit-depth of 12-14 bit images (depending on your sensor) that your camera captures. This provides a higher dynamic range for you to work with.

It is commonly known that with RAW shooting, you get up to 2 stops of exposure details to retrieve back, though this is rarely ever the case and depends to a huge extent on a number of conditions, namely: your camera exposure settings at the time of shooting, the scene in question, and your sensor. In reality, you can generally get away with retaining something between a half to one stop of exposure detail. Of course if you’re shooting JPEG or TIFF then there’s no such luxury, as the image will have been converted back to 8-bits by the time it reaches the camera storage.

Basic image post-processing decisions usually mainly entail:

• Adjusting exposure (in the case of shooting RAW).
• Fixing white balance.
• Clipped highlight recovery.
• Opening up shadows.
• Fixing global or local contrast if necessary.

Most basically put, in black and white photography there are only 3 main image qualities to work with:

• Tonal range.
• Brightness.
• Contrast.

It is inevitable that changing one of these 3 attributes will affect the other two. So there is no first or last when it comes to editing or fixing these values. You might always need to go back to one after fixing the other, till you end up with the result you desire. Your histogram is the most important tool that will let you know what needs to be done.

Tonal range

Tonal range refers to mid-tone values expanding to occupy the scale between the lightest and darkest points of an image. The wider the range expands, the more contrast there is, and the more mid-tone values would be represented in the image. An image with a narrow tonal range would cover a more restricted area between its lightest and darkest values, thus mainly consisting of mid-tones and in turn, having less contrast.

In a perfect world, the typical case would be that the tonal scale of your image would exactly fit the dynamic range your camera can capture (the entire scale of the histogram), with the white point and black point of the scene exactly falling on the white point and black point of the histogram and your exposure being right on!! Sadly, of course, that’s hardly ever the case.

 The other common 2 scenarios are: Scene having less tonal range than the sensor can handle, which gives you a great deal of flexibility in deciding where you would want your white and black points to fall. The other, most common scenario is having a scene with a dynamic range that is greater than what your sensor can capture. In this case, you’ll see the highlight and shadow ends of the tonal range mashed up against the left and right ends of the histogram. This gives rise to the common highlight and/or shadow clipping problem we often face.

Highlight clipping, as we’ve seen in a previous post, is more dreaded than losing shadow detail, probably mostly because of the increasing popularity of the silhouette. If you’re shooting RAW, you have a good chance of restoring some lost details, up to a half or one stop as we’ve discussed earlier. Shadows can also be retained as well, but just up to a certain point before noise starts cluttering up the image.

Brightness

Brightness is the difference in luminance from the darkest to the lightest areas of the image, or more simply is the scene’s perceived degree of light intensity.

Editing image brightness in post-processing mainly means changing mid-tone values up or down the scale without affecting the original black and white points of the image. This is why it might make more sense to first set the black and white points of your image as desired, and then adjust the overall brightness.

The difference between adjusting exposure and adjusting brightness is, exposure adjustment alters the black and white points of the image as if you’re actually changing your exposure settings at the time of shooting, thus if done aggressively can cause highlight or shadow clipping (though the Recovery and Blacks sliders can somewhat fix that ). Brightness on the other hand just moves the middle tones between both extremes higher or lower down the scale, so it won’t introduce any clipping.

One last thing to keep in mind is that using the recovery slider on an image extremely, can cause you to introduce flattening to the upper tones just below the actual highlights, so you might wanna keep that in mind.

Contrast

Contrast is the range of tones across an image, from bright highlights to dark shadows. The traditional way of increasing contrast, since the days of film and the darkroom, is applying what is called an S-curve.

To apply an S-curve, you simply pick a point in the lighter part of the scale and drag it lighter (upwards and/or to the left in Photoshop’s curves adjustment tool). You then take another point in the darker part of the scale and drag it darker (downwards and/or to the right in Photoshop’s curves adjustment tool). You then end up with an S looking curve.

The opposite, that is reducing image contrast, is done by applying a reverse S-curve. To apply a reverse S-curve you pick a point in the lighter part of the scale and drag it darker (downwards and/or to the right in Photoshop’s curves adjustment tool). You then take another point in the darker part of the scale and drag it lighter (upwards and/or to the left in Photoshop’s curves adjustment tool). You then end up with an S looking curve but reversed.