A practical course in photography how to use light to make good pictures

The concept of aperture

Aperture should be when we contact exposure, to understand the first concept, the number of aperture is very strange, and there is no law, F2.8, F4, F5.6 ... Wait, but the aperture for photography is very important, many professional photographers only rely on the big aperture can move the world, so let us first understand what is aperture.

Aperture is the use of light through the lens, into the fuselage of the photographic surface of the light device, has done the lens, it is impossible to change the diameter of the lens at will, but can be added to the lens of the multilateral, the use of a variable area of the hole-like grating to control the lens through the light

In short, the lens set a small hole, and then a series of small holes in the arrangement of blades, through the angle of these blades to control the size, the larger the hole, the more light into the beam, the smaller the hole, the less light into the lens.

In practical use, according to different environmental conditions, the external camera light is strong and weak, so you need to adjust the aperture to give the camera the right amount of light. For example, adjust the camera to M, do not change the ISO and shutter, the use of different aperture shot out of the picture will have a significant difference, the larger the aperture of the photo, the more light aperture, the smaller the picture darker. The different aperture changes, will have the remarkable influence to the photograph effect.

Aperture also has an interesting feature, the larger the number, the smaller the aperture, the darker the picture, on the contrary, the smaller the number represents the larger aperture of the photo, which is based on the calculation formula aperture.

The aperture f value = lens focal length/lens aperture diameter. The complete Aperture value series is as follows: F1.0,f1.4,f2.0,f2.8,f4.0,f5.6,f8.0,f11,f16,f22,f32,f44,f64.

Aperture of the stall design is adjacent to the value of two files 1.4 times times (2 square root 1.414 approximation) between the adjacent two stalls, twice times the diameter of the light transmission hole, the area of light transmission hole is one times, the film formed on the image brightness difference one times, the same amount of exposure required to maintain the same time difference.

It is worth mentioning that the smaller the aperture f value, the larger the aperture, the more the amount of light in the same unit of time, and the upper level of light is just twice times the next level. For example, the aperture from the F8 adjustment to F5.6, the amount of light into a more than one, we will say that the aperture opened a large level. F5.6 is twice times the amount of light that is F8. Similarly, F2 is the F8 luminous flux 16 times times, from the F8 adjustment to the F2, Aperture opened up four levels. For a consumer digital camera, the aperture f value is often between f2.8-f11. In addition, many digital cameras in the adjustment aperture, you can do 1/3 level adjustment.

The function of the aperture is to determine the amount of light into the lens, simply put, in the shutter speed (exposure speed) unchanged, the aperture f value of the smaller aperture of the larger, the more light, the screen is relatively bright; aperture f the larger the aperture is smaller, the screen is relatively dark.

To get an accurate exposure, you need to practice the aperture first.

When you use a zoom lens, the aperture changes. As you adjust the ring, the aperture value becomes smaller because the focal length is changed. For example, the general lens will be labeled such information, Canon ef-s 18-135mm f/3.5-5.6 is that, the focal length of 18, the maximum aperture is 3.5, but in the long focal lengths, the maximum aperture is reduced to 5.6.

Therefore, when shooting, in the wide angle of the opening to the big aperture, it is possible to exposure and depth of the appropriate, but if the focal length of the long focal lengths, it may lead to the lack of exposure.

Next, let's talk about depth. This is a concept that is closely related to aperture, and the simplest definition is that when the focal length is aligned to a point, the picture is still a clear area. Selecting different aperture values also results in different depth of the scene. So let's take a look.

In the character works, often pursue is the character image clear sharp, but the background is dreamy dim. And landscape works, people hope that can be photographed in the whole area can be clear. Choose a different depth of the effect, aperture, lens and distance will be associated.

Landscape photography, suitable for the "great depth" performance from far to near, suggests that the aperture is below F/8

First understand the principle of depth of the scene, the depth of the picture has the most direct impression. When the camera is focused, it can be clearly imaged before and after the focus, which can be seen at the same time as the depth of the imaging space of the eye, i.e. depth of field. Pick up the camera to adjust to AV (aperture first) mode, adjust the different aperture to observe the objects, you can see the obvious depth of the different effects, especially the maximum aperture and minimum aperture.

So many people who get into photography are biased towards the pursuit of large aperture effect, large aperture can be a good shot out of the dark scenery, but also to let irrelevant background, the effect of highlighting the main body, but also shooting portrait of Still life and other subjects necessary. and large aperture lens and cheap easy to obtain, canon or Nikon and other mainstream SLR manufacturers have 50mm f/1.8 lenses, about 4000 of the price can be bought. Professional portrait photographers in order to pursue better results, will also consider f/1.4 f/1.2 and other lenses, feel the charm of large aperture.

Again, focus. Large aperture lenses are mostly concentrated in the 50mm focal length segment, 50mm is the standard focus lens, but also one of the most popular lenses, are inexpensive, is also recognized as the closest to the focal length of the eye, at the same time conducive to connecting the focus of photographic observation, if you are in the socket and zoom on the bottleneck and confused, may try to set the Coke, Feel the charm of the big aperture. Of course, in addition to 50 1.8 there are 50 1.4 and 50 1.2 lenses to choose from, in addition to the largest aperture has increased, their imaging quality and workmanship will have better performance, but the price will be higher, users can according to their own needs to buy.

If you want to contrast the actual situation, the use of larger aperture, can reach the fuzzy effect of the coke outside

Big aperture is not omnipotent, many photos need a background to express the atmosphere and state, so must be based on the actual situation to use.

Here is a small trick, for a lens, the best large aperture effect, is often not the largest aperture, when the lens adjusts to the maximum aperture, such as 50mm f/1.8 lens, f/1.8, prone to loss of coke, distortion, chromatic aberration and purple edge and so on, Usually can try to reduce the 1-2 stop aperture, the imaging effect will be more sharp, the screen's permeability, contrast and so on will have better performance.

To mention a small light circle, small circle because of the contraction of the aperture, to reduce the amount, this will require a longer shutter time to ensure proper exposure, so when the scene light is not bright enough, you want to make the panorama clear and less noisy, aperture used above F/8, in order to prevent the body jitter, and longer exposure , you may need the support of a tripod and other external forces.

Whether using a big aperture or a small light circle, is the magic of your hand, because no light circle will have a different effect on the photo, this is based on the actual situation and the photographer's judgment and feeling to play.

Aperture size and imaging quality

The extreme aperture effect may bring unexpected effect to the photographer, but the true best imaging quality is to stay in the center aperture numerical value, the physics optics principle, when the aperture diameter is over the hour, the light diffraction phenomenon will be very serious, will affect the imaging quality. And when the lens aperture is too large, the lens due to the limitations of the production process, will produce different imaging errors.

If the maximum aperture of a lens is 1.4, the minimum aperture is 16, then this lens's best imaging effect in the aperture 4 or 5.6, generally speaking, the best aperture in the lens maximum aperture contraction 2 to 3 level position, may as well take the camera to try, this kind of difference in the picture enlargement will have the obvious difference.

With different aperture effects to create a different atmosphere, this must depend on the photographer's judgment

So what's the best way to choose the aperture when shooting? This is a problem for everyone who just picks up the camera.

If you're shooting portrait and still life, with the effect of the light depth of the large aperture, the realization of the wonderful before the virtual, so that people pay more attention to focus in the center, virtual unnecessary interference and clutter, if the light in the scene under the scenes, large aperture can also bring you a clean and comfortable effect.

Of course, the documentary humanities and some different, many documentary photographers will use a medium aperture, record the characters in the environment and state, so that people and the environment interrelated and interactive, which will be based on different shooting theme to decide.

And the general landscape photographer will prefer the small size of the large depth of the scene, so that when shooting can be photographed everything is a clear effect, enhance the rendering power of the screen.

And in shooting fast moving objects, with the big aperture to ensure a better shutter speed, to ensure that the moment of capture will not lose focus.

No matter what kind of shooting theme has no fixed rules and patterns, are based on the photographer's own performance needs, to choose a different effect.

For those who love photography, the camera manufacturers provide a large number of lens groups to achieve different effects and patterns, and professional photographers have their most competent and familiar lens focal segment, so use your focal length.

Aperture priority mode

Aperture this basic to finish, now say aperture priority mode, just get started photography novice, can start from semi-automatic AV file to learn debugging camera. Adjust the different aperture size, the camera according to the specific situation to match the appropriate number to ensure correct exposure, which is also a lot of portrait photographers love Magic weapon.

Do not think that small format machine can not take high-quality photos in the travel, small DC camera can also take a good moment

For many people who like simple photography, using the optical circle is enough to make a good picture of heart satisfaction, and sometimes professional photographers and ordinary photographers love the gap is not very big.

Portrait photos also need to use small light circle to show a clear depth of the time, so according to the actual shooting situation to decide

The introduction of photography is actually very simple, but the world of light and Shadow is very wonderful, let countless people chasing and love, back on camera, to take the most beautiful moment. Photography actually brings us a kind of pursuit of a beautiful life, because want to film more beautiful, so will go to explore and search. The above is a tutorial network small series for everyone carefully collected content, hope can be a beginner photography friends benefit Oh.