The lens aperture is: what is it and what does it serve?

Everyone wants to get beautiful bright images when taking pictures.However, very often it turns out that at the sight of an interesting point you have time to shoot it, but the photo turns out some dark.This may be guilty lens with a weak luminosity.That is why it is so important to know what is the lens aperture.Let's understand this.

lens aperture is another very significant parameters.It is just as important as the focal length, the angle of view, and others.This parameter characterizes the brightness of the image, which was built on the matrix of the lens.The more fast lens, the brighter the image they created.And at less than the index it will be darker.

Aperture is characterized by the relative size of the opening value and is denoted in the form of a fraction.For example, the inscription ¼ means that the relative size of the lens opening ¼ diameter of the hole is less than four times the focal length setting.It is important to note that the size of the current real objective opening soon is

a virtual value.This diameter typically does not coincide with the diameter of the diaphragm or the front lens.

It actually calculate the size of the current objective hole, but it is impossible to measure.Traditionally, the relative values ​​are dependent on the size of the image field on which the instrument is designed.One can say that the lenses with the same focal length have a very high luminosity, for example, f / 1,4-f / 1,8, unlike those in which the focal length is variable.Usually optics with variable focal distance and aperture setting is also variable, because its construction is much simpler.

If we talk about it, based on some kind of example, we can say that if there is a marking on the lens of 20-80 / 3,4-4,7, it would mean that at a focal length of 20 millimeters relativehole size will be f / 3,4, and if the focal length becomes 80 mm, the aperture changes and becomes f / 4,7.However, the higher the aperture of the lens, the more expensive the device itself.

It would be ideal to have in your arsenal with a set of different values ​​of this parameter, but for ordinary people this is not an option, because spending on them incommensurable with anything.The meaning becomes so expensive equipment is only in the event that the photo will be printed in magazines or somewhere else, but otherwise not.

In the absence of such a goal only need to purchase a regular camera.Do not take the camera has a small measure of luminosity, as very soon you yourself feel that the photos are enough beautiful and bright, and this defect will not turn away.However, modern devices, even the most simple, have a very high-quality built-in automation.

Inherently lens aperture - a feature that shows the amount of light passing through the device.If we proceed from this provision, the lowest aperture lenses have allowed only a small aperture.Lenses can be slow or fast, i.e. having more or less depending on the aperture value of the aperture size, typically thereon and compares different cameras, whose focal length is the same.

According to this parameter as the lens aperture, often correlate different types of photography.It is believed that the maximum value of this indicator are obtained the best images at different degrees of illumination.If you use a varifocal lens, then you have the opportunity not only to change the focal length, but also to get a different aperture ratio.