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IRIS in the camera

The aperture in the camera - what is it?

Aperture - one of the parts of the camera lens, it takes an important part in the "construction" of the image.

What it is, how it works and how to use it, you must know every photographer who discovers the opportunities of shooting with manual settings.

What is the diaphragm and how it works

To understand how the aperture, it is importantunderstand how all cameras convert incoming light into an image. In order to better grasp the principles of the camera, it is best to bring a vivid example.
Imagine a completely dark room, in whichThere is a window with black glass through which light can not penetrate. If you open it slightly, leaving a small gap, you will see a thin strip of light on the opposite wall. If you open the window completely, the light filled the whole room. In both cases, the window was open, but the lighting characteristics are completely different. The camera performs the role of a window aperture, and the role of the wall on which the light falls - matrix, fixing the image. Just how wide open aperture, and defines many of the characteristics of future pictures. Many, but not all, as the diaphragm - not the only element that takes part in it.
What is a diaphragm? This flap is gathered by the so-called "petals", which rotates in a circle, forming holes of different diameters (see. The attached photos). Remember the analogy of a window? The size of the round hole which forms the movable petals analogous plowing width of the window. The diaphragm can consist of a different number of petals, and it also plays a role in building the image.

How to use a diaphragm

The camera settings and labelinglens aperture characteristics are indicated by the letter f with the assigned numeric values, such as: f / 1.2 or f / 16. It is important to remember that it uses an inverse relationship, that is, the lower the number, the larger the aperture (larger open "window"). Thus, the value of f / 1.2 means that the diaphragm disclosed broadly and matrix of light falls on a lot, and f / 16 - a little. When choosing a lens is important to pay attention to the markings f /. The lower its value (start from the standard f / 3.5), the better.
At maximum aperture the matrixIt gets plenty of light. This allows you to take pictures in low light without using a flash and long exposures. By the way, the shutter speed - this time interval, which determines the time during which the camera shutter remains open, letting in the light matrix. Going back to the analogy of the window, then this is the time during which you will keep it open.
In addition, the width of the opening of the diaphragm definesdepth of field. If to explain simply, it is the number of objects in the frame that are in focus and have a clear, sharp edge. At wide-open aperture of their number will be small. I'm sure many have seen the portraits, in which the man was captured clearly and the background is blurred. Or the focus is only a small part of the subject, and everything is blurred. In photography, this effect is called a beautiful "bokeh effect".
At maximum aperture can beseek to focus on the smallest details, and all other light sources in the image will be blurred to the point of multicolored round shape. Now it's time to go back to the diaphragm blades. The more of them (in standard, low-cost lenses, they are usually five to seven), the more they form a circular opening, and the softer will blur.
In contrast to the wide-open holes, coveredAperture provides a greater depth of field, that is, more and more objects will be in focus. It is widely used for shooting when you need to show all the details, such as architecture or landscape.
Also, such aperture settings needuse when shooting at night with a tripod and slow shutter speeds. Not in low light, namely, at night, when the number of light sources is minimal. A narrow aperture lets you capture outstandingly detailed images without "overexposure" in which all the details are visible.
Knowing the theory, it is important to experiment with differentthe aperture value yourself. Seeing the difference in the pictures, you can learn to choose the right things to different conditions and always achieve excellent results.

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