Picture Sharpness

This post is also available in: Deutsch Français Italiano

In photography, the sharpness distinguishes and showcases the details in your picture. The quality of photos is often measured by their sharpness and achieving a high level of sharpness is one of the most important goals in the technical implementation of photography. There is a difference to keep in mind between the technical picture sharpness and the subjective sharpness perceived by the viewer. Much significance is often attached to the latter since the impression of sharpness transports the artistic statement of the picture. Influencing factors such as surrounding conditions, technique, and the motif play a deciding role, but the picture’s sharpness can also be improved after the fact with the utilisation of picture optimisation programs. A picture taken with quality sharpness from the onset is always better than a picture whose sharpness has been improved digitally after the fact.

A fundamental element of the subjective sharpness is the edge definition. Edges in photos are especially sharp when they are exhibited on strong contrasts in brightness or colour. A picture without a clear structure or edges will be regarded as fuzzy or out of focus by the viewer. Besides the brightness of a picture, the colour temperature, or colour balance, also plays an important role. The colour temperature is made up of different wavelengths of light and is therefore affected by the light source and the colour of all the surrounding areas. For example, a portrait taken in front of a red wall will have a red hue. The different light-absorbing and reflective surfaces that surround the object being photographed affect the intensity, colour temperature, and contrast in the picture. With image enhancement, you can also adjust these effects in the photo after the fact.

The picture definition also contributes to the sharpness of the photo and depends heavily on the available exposure techniques and the quality of the lens. Only when the sensor of the lens obtains detailed information can these details be depicted. On the other hand, you can also have a photo with a high resolution, but a small amount of details; this will also result in a limited perception of sharpness. High quality lenses in combination with top-notch cameras are capable of achieving high image performance. Normally this can be monitored by using a number of lines shown by the lens.

The ISO settings for the exposure time also influence the resolution as well as the perceived sharpness. High ISO values cause an overlap of the picture details through image noise and reduce the resolution. The exposure time can also have an influence on the field depth and blurred motion.

A spatial impression of the motif is conveyed to the viewer through the depth of focus. Important influential factors here are, for example, the focal width and distance. Through a larger focal width and a smaller distance from the photographed object, the depth of focus will be reduced.

Motion of the object being photographed can also cause blurring in the picture. When this is not caused by flawed focusing, shutter priority, or mistakes in other operational settings, this is labelled as motion blur. This is caused by perceivable movement in the motif during the exposure time. Blurring in the photo is often unwanted since it is frequently the result of unintentional shaking of the camera which results in the photo losing sharpness. In order to give the picture a bit of a special effect, sometimes motion blur will be purposefully used in sport photography.