To make one of the most important factors as desired for a photo is the choice of aperture. With their help, you can not only determine how much light falls on the sensor. She also has a great influence on the depth of the image. What does this mean in practice, how to find the right attitude for the situation and cooperate with what other factors the panel, I would like to clarify on this page.
Surely you know these beautiful portrait shots where the background blurred and the person depicted is keen to see. In such images are working with a very shallow depth of field. The depth of field determines the range in your design, which is keen to see. He can (from the subject in the foreground to far into the background, for example, in landscape photography) extend over the entire depth of the image (= high depth of field). He may, however, as the example of the portraits focus only on a certain part while everything else in blur blurs (= shallow depth of field). In the latter case, it is extremely important to focus properly, therefore, to set the camera to the main subject in focus.
Aperture and depth of field
The iris is one of the factors that has a big impact on the amount of sharpness in your image. The following general rule: The more you open the aperture, the less depth of field / more blur you get on your image. The more you close the aperture, the more depth of field / less blur You've finally in the picture. You can download the try once by you to the subject snaps with different values for the aperture (Av or A mode most of your camera) at the same focal length and constant distance a few photos. Typical values for a wide-open aperture include f2.8 or f3.2, for a far closed aperture eg f18 f22 or. The result might look something like this, as the two sample images to the left. In this way, offer very different options to personalize your image conscious. Depending on what you want to photograph and how much light you is not available, open or closed aperture settings are to continue using.
Aperture and shutter
The panel has in addition to the impact on the depth of field but also an enormous impact on the exposure of the motif. If you have as described in the above paragraph, tried to photograph a subject in a far closed aperture (eg F22), it could have happened that the underexposure or blurred. The reason is as follows: The more you close the aperture, the less light falls on namely the camera's sensor. Nevertheless, in order to expose the image well, have other factors that have an impact on the exposure, compensate for the lack of light. This can, for example, be a higher ISO value or a slower shutter speed. Lenses where you can open the aperture very far (to f1.2, usually fixed focal length) are very popular to even take pictures without a tripod and flash even in low light rather good pictures, as the photo illustrates the right.
Effect of Aperture depending on focal length and distance to the subject
The influence of the f-number on the depth of field can vary significantly by two factors. On the one hand, the focal length of a direct impact on the effect of the aperture. Scan times a motif of your choice at a constant Aperture Priority (approx f4.0) in wide angle (approximately 20-25mm or less) and the normal to telephoto (from 50mm upwards). In a comparison you'll find that a lot more blurring is located in the photo with 50mm focal length. The farther you get so in the telephoto range, the greater the influence of the aperture to the Focus range. This influence can be zoomed in / out by you are photographing the subject closer / farther.
The interplay of all factors is at the beginning, of course, not too easy to understand, but when you have once practiced a while, you get slowly a sense and can assess which combination of aperture, focal length, and distance to the subject the most appropriate time getting better is for the situation! Have fun experimenting!