What is ISO in a camera? Digital and film cameras
Everyone who has a camera in their hands sooner or later decides to delve into its settings, sees a completely unfamiliar abbreviation there and wonders what ISO is in a camera. However, in reality, everything is not as scary as it might seem.
General concept
What is ISO in a camera? This is a measure of how receptive the light-collecting element of the camera is to the streams of light entering it. The higher this value, the less demanding the device is on the level of lighting when shooting, that is, it can be used to shoot in low-light places.
The ISO sensitivity of the camera was still characteristic of film models, and now this parameter characterizes not the film, but the matrix. The value is indicated in integer units, and the maximum and minimum allowable values for each model may vary depending on the presets provided by the manufacturer. The ISO number in the camera is very important when properly setting the exposure pair, that is, shutter speed and aperture. Sometimes even the selection of the optimal combination of these indicators does not allow you to get a frame with the correct exposure: either there is an excessive amount of light, or the picture is very dark.
How to use?
What is ISO in a camera is generally clear, now it should be said about the possibilities of using it. When changing its parameters, you can additionally adjust the sensitivity of the matrix in order to equalize the exposure of the future image without using the flash. To change the sensitivity index, the following stops are used: ISO 100, ISO 200, ISO 400, ISO 800, and so on, depending on the model. Each next stop is twice the difference between the previous two. Some higher-end models allow you to set intermediate values manually - ISO 250, ISO 500. If the selection is automatic, different values \u200b\u200bare used: 1400 and 240.
Operating principle
So, with what is ISO in the camera, in general terms, figured out, you need to decide on the principle of its operation. This can be done with an example. The subject is a street with poor lighting. Exposure - 1/20. Aperture in priority mode. ISO 100. These settings provide a blurry frame in most cases. This is due to the large shutter speed. That is, the camera stays open longer, managing to catch a lot of light. To avoid this, you need to lower the shutter speed, but increase the ISO value, which will not allow the picture to become dark. If the ISO is 800 and the shutter speed is 1/160 of a second, then the evening landscape can be shot without a tripod, and the frame will still be clear.
"Noises"
You already know how to adjust the ISO on the camera, but this does not mean that by setting the value to the maximum, you can automatically save yourself from worrying about the quality of the resulting image. If the indicator is too high, then the photographer will face a completely different kind of problem - a large amount of “noise” will appear in the picture. These are colored dots, from which the image quality is noticeably lame. Where do they come from? The thing is that an increase in the level of the electrical signal automatically leads to an increase in interference, which are extraneous signals that have nothing to do with the subject. The matrix itself also creates a certain level of "noise". You should not use the maximum ISO values, it is better to stick to neutral values of 200-400 for regular cameras and 400-800 for SLRs. And the lower these figures are, the better.
Digital cameras must be used in a certain way to ensure good quality pictures. When shooting, ISO should drop to a minimum, and setting the shutter speed and aperture allows you to choose the necessary exposure settings. Only in the case when it is impossible to change these values, it is required to increase the photosensitivity.
With what ISO to choose a camera?
The choice of camera should be based on certain recommendations.
Digital cameras are necessarily characterized by a maximum and minimum ISO value. That is what you should pay attention to. You should not chase after large values, since in practice they are unlikely to be useful. If you make a choice in favor of such values, then professional and semi-professional models should be considered as an acquisition, since their large matrix size does not allow “noise” to appear in the photo in large quantities. It is desirable that there is an ISO button on the camera, then it will be more convenient and faster to set it up. However, in "soap dishes" there is usually no such option, and the parameter must be accessed through a multi-level menu. In this case, it is important to remember the sequence of actions.
Features of models with an extended ISO range
On cameras with a higher ISO, the effect of “noise” in the pictures will be very noticeable. Most often, buying such a camera turns out to be pointless, unless you are printing pictures of small sizes, where the "noise" is not very noticeable. If the sensitivity is extended to a low range, then you can work with slower shutter speeds, while the image becomes less “noisy”, but a certain amount of contrast is also lost.
A high ISO value may be required at children's parties, sporting events where shooting is done at a minimum shutter speed, since in other cases the risk of getting blurry photos is too great. For example, in places where the use of flashes is prohibited, when taking pictures of memorable moments, such as kissing, blowing out candles on a birthday cake, and others. With a flash, the impression of these moments can be spoiled.
conclusions
So, ISO is just the degree of sensitivity of the matrix to light. The higher this value, the higher the sensitivity, as well as more "noise" in the picture, and vice versa. When shooting, it is best to lower this figure to a minimum, combining it with aperture and shutter speed values, which will allow you to get the desired effect. If shooting is done in conditions of high-quality lighting, then ISO is set no higher than 100-200. For cameras with a larger sensor, you can set higher values, as they are less susceptible to "noise".
Photography is not just a set of strict rules, it is also a space for creativity, so everyone can choose the values \u200b\u200bfor him. The reference point in this case is taken on taste preferences and the capabilities of technology. But the main desire should be for the harmony of the picture. If this is achieved through an unexpected experiment, then the skill of the photographer can be proved.
