The aperture has two poles, but it is interesting that most players only pay attention to the dreamlike depth of field under the large aperture, but often ignore the fascinating "vision" field under the small aperture. In this chapter, we will discuss the issue in depth, so that readers can think more about different aspects of image creation.
Why zoom in?
"Aperture without rotten mirror" is a joke circulated in the photography industry. Although joking is a joke, the Aperture (small aperture) can really bring substantial help to image quality, because in the process of reducing the aperture, not only the depth of field will become long-term, but also the resolution and sharpness of the subject will be improved, so that players can shoot. For some specific subjects, it is more realistic to present the image details. Because of the above characteristics, there is less requirement for lens quality or design structure. That is to say, you can use the Kit mirror at hand to complete most of the later topics.
[Note] Because the lens structure and lens group design are different, in the creation of zoom, except for some differences in quality, the biggest difference is the number of stars.
Generally speaking, in order to have the relationship between depth of field and environment, most players will reduce the aperture to F3.5 - F5.6, but this is not the scope of this chapter to discuss, not to mention here, we want to explore how to achieve great image creation under F8 - F22 minimal aperture.
_Under the issue of small aperture, the use of common Kit lens can meet the shooting needs of most subjects.
F2.8/F22. The aperture size has a direct impact on the depth of field and image resolution.
How many apertures is enough?
At present, the smallest aperture of most lenses is F22, but some lenses can be provided to F28-32, but no matter what, they can enjoy the pleasure of image creation brought by small aperture. But to what extent should the aperture be reduced to meet the shooting needs of various subjects? And is there a general rule to follow? The answer is not available. Generally, it can only be set through the rule of experience, but now using the depth of field preview key to predict, we can grasp the depth of field of the image preliminarily, so that the photographer can intuitively take the scene to capture the desired situation atmosphere. In addition, besides the zoom, the focal length of the lens should be changed according to the subject matter (for example, the wide angle should be between 10 and 16 mm) in order to meet the shooting needs of various subjects.
_Through the camera built-in depth of field preview button can preliminarily predict the situation of the scene, making it easier for the photographer to shoot the desired situation atmosphere.
some lenses have built-in depth of field meter design, so that through the display, we can know the depth of field under the current aperture.
Implantation of the concept of hyperfocal length
Hyperfocal distance is the "pan-focus" in the player's mouth. At present, it is mostly used in scenery or street photography and other subjects. What is pan-focus? In fact, when the lens aperture shrinks to a certain series, the image from infinite distance (_) to a certain position is clear, so the picture can get the maximum depth of field. However, at present, it is mostly suitable for wide-angle lens focal section (the depth of field covers a longer focal section of the lens) and readers need to pay special attention to the operation. When the focus is not on the hyperfocal, one end of infinite distance (__) cannot be included in the depth of field; conversely, when the focus is focused on the hyperfocal, the depth of field coverage will extend from half of the hyperfocal distance to one end of infinite distance (__), that is to say, assuming the hyperfocal distance is 3 meters, the depth of field is 1.5 meters to infinite distance (____ And so on.
Perspective and Application of Light and Film
In zoom photography, because of the long field depth, not only is the subject clearly photographed, but also the background is clearly recorded. Generally speaking, to have both the texture of the picture and the long-term depth of vision, we will use the "light and shadow" and "perspective" to solve the problem. For the former, the use of light and shadow changes to increase the three-dimensional sense of the picture, so that the front/back background can make a more obvious division, as shown in Figure 1 below, the original zoom is designed to create a sense of speed of the train, but in the light and shadow, we can clearly distinguish the building, train and pedestrians and other three blocks, so that the picture can be richer. As for the latter, it has the same effect as the former, but it brings out the hierarchical sense of the picture through the arrangement of the object specifications, as shown in Figure 2 below, because the front/back depth of field is quite clear, at this time, as long as we find out the rules or regularity of the picture, we can take a clear and interesting image. Like works.
Fig. 1: Through the foil of light and shadow, even if the front/rear depth of field is quite clear, it can easily bring out the layered sense of the picture. Canon EOS 650D + Tokina AT-X 11-16 mm F2.8 PRO FX 13 mm end. Aperture F16, shutter 1/50 second, ISO 100, AV aperture pre-shooting mode, automatic white balance, JPEG
Fig. 2: If there is no light and shadow foil, we can find out the rules or regularity of the picture, which can also create a hierarchical image effect. Canon EOS 5D Mark II + Tokina AT-X 17-35 mm F4 PRO FX 20mm end. Aperture F14, shutter 8 seconds, ISO 100, AV aperture pre-shooting mode, automatic white balance, JPEG
Scaffold Auxiliary Necessary
To create a zoom, the first problem is that the shutter speed is easy to slow down. Generally speaking, when the shutter speed is lower than the safety shutter in the shooting process, we first suggest that the player can open the shock-proof mode and raise the ISO sensitivity assistance. If it is still not enough to use, we will recommend lifting the chest or tripod assistance. To indirectly reduce the probability of image blurring. What is the safety shutter? In fact, it is the reciprocal of the lens focal length. Take the 50mm focal length as an example, its safe shutter is 1/50 seconds (APS-C is 1/80 seconds; see note). If the hand-held shooting is still below that value, the above method must be applied to solve it.
[Note] Sometimes the safety shutter is not the reciprocal of the focal length of the lens. If the focal length is 90 mm, but the camera does not have a shutter speed of 1/90 seconds, then the close and the next 1/100 seconds will be chosen as the corresponding.