Anyone new to photography is bound to be exposed to the concept of exposure, "exposure" and photography go hand in hand, canvas prints understanding exposure must be clear about the camera aperture, shutter, but the novice to see this provocative parameters often at a loss. It's not hard to figure out these concepts, but let's take each of these seemingly complex concepts one at a time, and enter into an interesting world of light.
Aperture should be the first concept we should understand when we come into contact with an exposure. At first glance, the aperture value is very strange and irregular. F2.8, F4, F5.6... But aperture is very important for photography, canvas prints australia many professional photographers can walk the world with only a large aperture, so let's first understand what is aperture.
Aperture is an optical device that USES light to pass through the lens and enter the photosensitive surface inside the body. The finished lens is impossible to change the diameter of the lens at will, panoramic canvas but polygons can be added inside the lens and the aperture grating with variable area can be used to control the amount of light passing through the lens.
To put it simply, a small hole is set in the lens, and a series of blades are arranged in the middle of the hole. Through the Angle of these blades, the size can be controlled. The larger the hole is, the more light will enter the lens, and the smaller the hole is, the less light will enter the lens.
In practical use, according to different environmental conditions, the external light into the camera is strong or weak, so we need to adjust the aperture to give the camera the right amount of light. For example, if the camera is adjusted to M without changing the iso and shutter speed, the photos taken with different aperture will be obviously different. The difference in aperture can have a significant impact on the image.
Another interesting feature of aperture is that the larger the number, the smaller the aperture, the darker the photo. Conversely, the smaller the number, the brighter the photo with the larger aperture, according to the formula of aperture.
Aperture F = focal length of lens/aperture diameter of lens. The full aperture series is as follows: F1.0, F1.4, F2.0, F2.8, F4.0, F5.6, F8.0, F11, F16, F22, F32, F44, and F64.
The gear design of the aperture is 1.4 times the difference between the values of the two adjacent ranges (the approximate value of the square root of 2 1.414). Between the two adjacent ranges, the diameter of the light transmission hole is 2 times the difference, the area of the light transmission hole is twice the difference, the brightness of the image formed on the negative is twice the difference, and the time required to maintain the same exposure is twice the difference.
It is worth mentioning that the smaller the aperture F is, the larger the aperture will be, and the more light will be input in the same unit of time, and the amount of light input in the upper level is exactly twice as much as that in the lower level. For example, if the aperture is adjusted from F8 to F5.6, the amount of light will be doubled. F5.6 has twice as much light as F8. Similarly, F2 is 16 times the luminous flux of F8. When the aperture is adjusted from F8 to F2, the aperture is opened up by four levels. For consumer digital cameras, f-stop values often range from 2.8 to 11. In addition, many digital cameras can adjust their aperture by a third.
The role of aperture is to determine the amount of light into the lens. Simply put, when the shutter speed (exposure speed) is constant, the smaller the aperture F, the bigger the aperture, the lighter in, the brighter the picture.
To get accurate exposure, practice aperture first
When using a zoom lens, the aperture changes accordingly. When adjusting the zoom ring, the aperture value decreases as the focal length is changed. For example, the Canon ef-s 18-135mm f/ 3.5-5.6is means that at 18 the maximum aperture IS 3.5, but at the long end it IS reduced to 5.6.
Therefore, when shooting at a wide aperture, the exposure and depth of field may be appropriate, but if the focus is pulled to the long end, the exposure may be insufficient.
Let's talk about depth of field. This is a concept closely related to the aperture. The simplest definition is that when the focal length is aligned to a certain point, the front and back of the image are still clear. Choosing different aperture values also results in different depth of field effects. So let's see.
In the works of characters, it is often pursued that the images are clear and sharp, but the background is dreamy and hazy. In landscape works, people hope that the whole landscape can be clear. Choose different depth of field effects, aperture, lens and distance will be related.
Landscape photography, suitable for "large depth of field" expression from far to near, so the aperture is recommended below F/8
First understand the principle of depth of field, depth of field in the picture has the most direct perception. After the focus of the camera is completed, the image can be clearly formed in the range before and after the focus, and the spatial depth that can be clearly seen at the same time is called the imaging spatial depth of the eye, that is, the depth of field. Pick up the camera and adjust it to AV (aperture first) mode. Adjust the different apertures to observe the object you are photographing.
So many people prefer to pursue a large aperture photography, large aperture can be a good shot of the dark scenery, but also can make irrelevant background blurred, the kind of prominent effect, but also shooting portrait still life and other subjects necessary. Large aperture lenses are cheap and easy to get. Mainstream DSLRS like Canon or nikon have 50mm f/1.8 lenses, which can be purchased for around 4000. Professional portrait photographers will also consider F/ 1.4f /1.2 and other lenses to feel the charm of large aperture in pursuit of better results.
Let's talk about focal length. Large aperture lens focused on 50 mm, 50 mm is the standard focal length lens, also is one of the most popular scenes, are inexpensive, the focal length is also recognized as the most close to human eyes, at the same time to photography observation of focal length, if you are on the set of head and zoom bottlenecks and vague, might as well try a fixed focus, feel the charm of large aperture. Of course, in addition to 50 1.8, there are also 50 1.4 and 50 1.2 lenses to choose from. In addition to increasing the maximum aperture, their imaging quality and workmanship will also be better, but the price will be higher, so users can choose according to their own needs.
If you want the contrast between virtual and real, use a larger aperture to achieve the blurry out of focus effect. Large aperture is not a panacea, many photos need background to express the atmosphere and state at that time, so it must be used according to the actual situation.
Say a little trick here, for a lens, presented the best large aperture effect, often is not the time for aperture value maximum, when the lens to adjust to the maximum aperture, such as 50 mm F / 1.8 lens, F / 1.8, prone to out-of-focus, distortion, and the purple color edge, 1-2 aperture, it is usually possible to try to reduce the imaging effect will be more sharp, images appear a degree, contrast and so on will have better performance.
Ask a small aperture, the shrinkage of small aperture for aperture, into the light, this time a longer shutter speed is required to ensure the right exposure, so when the scene under the condition of the light is not bright enough, to want to take a panoramic view of clear and less noise, aperture used F / 8 or more, in order to prevent body shaking, and the longer time of exposure, may need a tripod external forces such as auxiliary.
Whether you use a large aperture or a small aperture, it is the magic of your hands to change, because not using an aperture will have a different effect on the photo, this is based on the actual situation of the scene and the photographer's judgment and feeling to play.
Aperture size and imaging quality
Extreme aperture effect may bring unexpected effects to photographers, but the real best imaging quality is the aperture value in the middle. In the principle of physical optics, when the aperture diameter is too small, the diffraction phenomenon of light will be very serious, which will affect the imaging quality. However, when the aperture of the lens is too large, the lens will produce different imaging errors due to the limitations of production technology.
If a lens has a maximum aperture of 1.4 and a minimum aperture of 16, then the best imaging effect of this lens is on aperture 4 or 5.6. Generally speaking, the best aperture is in the position of the lens with a maximum aperture of 2 to 3 levels.
Different apertures create different atmospheres, depending on the photographer's judgment. This is a problem that bothers everyone who has just picked up a camera. If you are shooting portrait and still life, use the effect of shallow depth of field with a large aperture to achieve a wonderful front and back effect. This can make people pay more attention to the center of focus and blur out unnecessary interference and sundry. If you are shooting in a sunny scene, a large aperture can also bring you a clean and comfortable effect.
Of course, there are some differences in documentary culture. Many documentary photographers will use the medium aperture to record the environment and state of the characters, so that people and the environment are related and interactive, which depends on different shooting themes. The average landscape photographer will prefer a small aperture with a large depth of field, so that everything can be captured clearly when shooting, enhancing the rendering power of the picture.
When shooting fast moving objects, canvas photos online using a large aperture to ensure better shutter speed, to ensure that the capture of the moment will not lose focus.
No matter what kind of shooting subjects have no fixed rules and patterns, are based on the photographer's own performance needs, to choose different effects.
For those who love photography, various camera manufacturers offer a large number of lenses to achieve different effects and patterns, and professional photographers have their own most competent and familiar lens segment, so use your own focal length.
Aperture first mode
Aperture this basic to say the end, now say aperture priority mode, just beginning photography novice, can learn to debug the camera from the semi-automatic AV file. Adjusting different aperture sizes and matching appropriate values to ensure the correct exposure is also a favorite of many portrait photographers.
Don't assume that a small frame machine won't be able to take great photos on the road, but a small DC camera can also take great moments. For many people who like simple photography, with the aperture is enough to take a heart satisfied with good photos, sometimes professional photographers and ordinary photographers love the gap is not very big.
Portrait photos also need a small aperture to show a clear depth of field, so it depends on the actual shot. Introduction to photography is actually very simple, but the world of light and shadow is very wonderful, so many people chase and love, back camera, to take the most beautiful moment. Photography actually brings us a kind of pursuit of beautiful life, because we want to take more beautiful pictures, large canvas print so we will explore and pursue.