There are fundamentals in photography, without knowing which, it is impossible to learn how to take high-quality and beautiful pictures. One of those things is understanding the exposure of a frame. In our article we will talk about shutter speed, aperture and sensitivity. It is these things that form the exposure and an understanding of their work is necessary to get good shots. We will explain what shutter speed, aperture and sensitivity are and how to work with them effectively.
Introduction.
Before writing what shutter speed and aperture are, a small digression. Each frame requires a certain amount of light (exposure). The camera has three options to dose the light output: aperture, shutter speed and sensitivity. Sensitivity is used only when the situation does not allow changing the shutter speed and aperture. In addition to controlling the amount of light entering the sensor, shutter speed and aperture are effective artistic tools. First you need to understand them, and with time and experience, ease of use will come. An experienced photographer uses these tools on a subconscious level.
Diaphragm.
(diaphragma - partition, Greek), in English "aperture" (aperture, English)
Diaphragm- an element of the lens design that is responsible for the diameter of the hole that transmits light to a light-sensitive surface (film or matrix).
For a simple understanding of the aperture, I will give an analogy with a window. The wider the window shutters are open, the more light comes through the window.
Aperture is denoted as f/2.8 or f:2.8, defined as the ratio of the diameter of the lens inlet to the focal length. Very often, the concepts of an open, large aperture (f / 2.8) and a large f / 16 aperture are confused. The smaller the number in the designation of the aperture, the more it is open.
By changing F by one value, the amount of light entering the camera changes by 2 times. This is called the exposure stage. Any changes (according to the scales of the camera) exposure occur in 1 step increments. For accuracy, the step is divided into thirds, if necessary.
Aperture is a very powerful visual tool. The maximum open aperture gives a very small depth of field (depth of field of the imaged space). Small depth of field visually highlights the object against a blurred background.
To obtain a large depth of field, the most closed aperture is used. To get a greater depth of field in your frame, use f-number 8 or larger. However, when playing with the aperture value, remember that there are the following dangers when approaching extreme aperture values. When open, the sharpness readings are the worst, and when closed, all the dust on the matrix will be visible on the frame (for digital cameras).
A large depth of field is more suitable for landscape photography, when it will be interesting for the viewer to see all the details of the photo.
Excerpt.
Excerpt- the time interval for which the shutter opens to transmit light to the photosensitive element.
Again, the open window analogy will help. The longer the shutters are open, the more light will pass through.
Shutter speed is always measured in seconds and milliseconds. Indicated as: 1/200, only the denominator is displayed in the camera: 200. If the shutter speed is a second or longer, it is indicated as 2″ i.e. 2 seconds.
The minimum shutter speed when shooting handheld (to get a sharp shot) is not constant and depends on the focal length. The dependence is inverse, i.e. for 300 mm it is better to use shutter speeds shorter than 1/300.
Long exposure emphasizes the movement of objects. For example, panning - at slow shutter speeds, 1/60 and longer, the camera follows the subject, so the background is blurred and the subject remains sharp.
The flowing water at a slow shutter speed turns into frozen figures.
Very fast shutter speeds, I use to stop a moment, such as a spray of a fallen drop or a car flying by.
ISO sensitivity.
Sensitivity- this is a purely technical concept, denoting the sensitivity of the matrix (or film) to light. Imagine sunbathing people on the beach. Those with more sensitive skin will tan faster; he needs less light for that. The other, on the contrary, needs more light to tan, because he has low sensitivity.
Sensitivity is directly related to the amount of noise. The higher the ISO, the more noise, and the grain size of the film. Why? Purely technically, in general, this is the topic of an extended article.
At ISO 100, the signal is taken from the matrix without amplification, at 200 it is amplified by 2 times, and so on. With any gain, interference and distortion appear, and the greater the gain, the more side effects. They are called noise.
The intensity of noise is different on different cameras. At minimum ISO, noise is not visible and is also less apparent when processing a photo. Starting with ISO 600, almost all cameras are quite noisy, and to get a high-quality frame, you need to use noise reduction programs.
Outcome
Together, the shutter speed and aperture values form an exposure pair (the optimal combination of shutter speed and aperture for the given lighting conditions). Expopara determines the exposure of the frame. Previously, exposure meters were used to determine the exposure, which determined the shutter speed based on the amount of light and aperture. Previously, the exposure meter was used as a separate device, today it is built into almost every camera.
Every DSLR has shutter and aperture priority modes. In aperture priority mode, the aperture is selected, and the camera, analyzing the level of light, selects the shutter speed. The opposite is true in shutter priority mode. Almost always I use aperture priority, it gives the opportunity to work with depth of field. If there is a need to shoot movement, I use the shutter priority mode.
In our next articles, we will continue to talk about the basics of photography. After all, it is in these things that the understanding of the art of photography lies. Knowing them, you will be able to create the shots that you want.
