The camera histogram is God! Every pixel of the photograph is represented in the camera histogram. Starting with an underexposed image, as we brighten the exposure the histogram moves to the right; redistributing the pixels to reflect the tones of the exposure. The histogram pinned at the corner; the black point. The histogram is a very sharp, vertical ‘pyramid’ shape. As we increase the exposure, the sharp ‘pyramid’ falls over, gradually taking on a very smooth ‘hump’ shape; still pinned at the black point. Increase the exposure more, the shape of the histogram remains constant – but ‘pulls away’ at the black point; a small gap appears in the left corner. This is now your optimum exposure for maximum shadow quality and detail. Imagine the histogram, equated to taking off in an aircraft. Steep histogram, brutal take off. Smooth histogram, enjoyable take off. Same with tone; a smooth histogram means smooth, rich tone full of detail.
Exposures are the digital assets we require to create our photograph in Photoshop. There are three types of Photoshop assets we need to capture. The base image is our best attempt to get the perfect photograph in one single frame. This becomes the final photograph after additional assets are added. Technical assets, principally bracketed exposures as discussed and artistic assets where the light strikes subjects in the scene not captured in the base image; light falling on the surrounding hills or secondary heroes for example. The more artistic assets, the more creative freedom we have later in Photoshop retouching. This process requires every exposure to align up ‘pixel-perfect’ in Photoshop. The ability to align multiple exposures in Photoshop is central to my whole photography technique but opens a whole new world of creative possibility. This also allows us to shoot any contrast level or situation without resorting to HDR software.
Tonal quality begins at the camera. How we expose our photographs makes a tremendous difference to the quality, the richness of tone in our final photograph. If we do not get this correct at the camera, it’s too late when at home. Cameras do not and never will record, what we see. Equally, cameras have built in presets. We need to set all these to zero, so the camera does not manipulate the raw material, our digital assets; we want to retain total control of the quality ourselves. So, when do you leave? Generally, when you are cold, wet, bored and depressed or talking to the sheep because you’re so lonely. When God looks down and sees a photographer, he rubs his hands with a big grin and says ” I’m going to have fun today”. He is going to play with you! Just after you leave, the sun comes out like a Rembrandt painting, but stops just as you run back to capture it! When do you leave? When you have all the digital assets you need.
David Osborn | Professional Photographer, London, 2020