This series of photographs and their associated histograms covers images with multipeak histograms, which come is many differing forms. None of these images is perfect, but they illustrate the fact that sometimes the perfect image is not possible given the constraints of the scene – shadows, bright skies and haze, sometimes they are just unavoidable.

Histogram 1: A church and hazy hills

This photograph is taken in Locarno, Switzerland, with the church in the foreground the Madonna del Sasso. The histogram is of the multipeak variety, with few highlights. The left-most hump (①) represents the majority of the darker colours in the foreground, e.g. vegetation, and the parts of the building in shadow. The remaining two peaks are in the midtones, and represent various portions of the sky (③) as well as the lake, and hazed over mountains in the distance (②). Finally a small amount of highlights (④) represent the clouds and brightly lit portions of the church.

Histogram 2: Light hillside, dark forest

This is the Norwegian countryside, taken from the Bergen Line train. It is a well contrasted image, with only one core patch of shadow (①), behind the trees in the bottom left (there are a few other shadows in foreground objects such as the trees on the right). The midtones, ②, represent the rest of the landscape, with the lightest midtones and highlights composing the sky, ③.

Histogram 3: Gray station

This photograph is of the train station in Voss, Norway. It is an image with a good distribution of intensities, with four dominant peaks. The first peak, ①, is representative of the dark vegetation, and metal railings in the scene, overlapping somewhat into the mid-tones. The central peak (②) which is in the midtones, represents the light green pastures, and the large segments of asphalt on the station platform. The third peak, ③, which transitions into the highlights mostly deals with the light concreted areas. Finally there is a fourth peak, ④, which is really just a clipping artifact related to the small region of white sky.

This series of photographs and their associated histograms covers multipeak-unimodal histograms, i.e. images which have a histogram which has a core unimodal shape, yet is festooned with peaks.

Histogram 1: A statue against the sky

This image, taken near Glasgow Scotland, has a broad spectrum of intensity values. The histogram has an underlying core “unimodal” shape, bias towards highlights, a result of both the statue and the clouds. The image has exceptionally good contrast. The jagged, multipeak appearance is an artifact of the broad distribution of intensities, and intricate details, i.e. non-uniform regions, in the image.

iPhone 6s (12MP): 4.15mm; f/2; 1/3077

Histogram 2: Oslo lion

This image, taken in Oslo (Norway), is the “poster-boy” for good histograms (well almost). It has an underlying unimodal shape, mostly in the midtones. It is a well-formed image with good contrast and colour. There are shadows in the image, but that is to be expected considering the clear sky and the orientation of the sun. There are no pure blacks in the image, the shadow tones created by the dark windows. There are also few whites, less than 1% of pixels, that are the result of light reflecting off light surfaces (such as the lion).

iPhone 6s (12MP): 4.15mm; f/2; 1/1012

Histogram 3: Plateau river

This image, taken from a moving train on the Bergen Line in Norway, high up on a mountain plateau. The histogram has an underlying core unimodal shape, composed predominantly of midtones, in addition to the lighter end of the shadows (①). There are no blacks and few highlights to speak off. The image has exceptionally good contrast. The jagged, multipeak appearance is an artifact of the image detail, i.e. non-uniform regions, in the image. For instance the sky tapers gradually from 150 to 190 near the top of the hill.

Olympus E-M5(II) (12MP): 12mm; f/7.1; 1/400