（1） , light and exposure [Film/photosensitive sensor] The main parameters of the film refer to those of the film, which are marked with ISO values (short for International Standards Organization). The higher the ISO value, the higher the film/photosensitive sensor, and the easier the exposure. Aperture There is a set of overlapping metal blades inside, and the aperture size and opening time enclosed by them determine the exposure amount of a phase formation, as well as the aperture and speed of the camera. When the exposure time is fixed, the larger the aperture, the greater the exposure amount of the film. It is expressed as f/value. General cameras include f/1.4 f/2、f/2.8、f/4、f/5.6、f/8、f/11、f/16、f/22， Every time you jump up or down a space, the amount of exposure will be doubled or halved accordingly. [Shutter] Of course, it mainly refers to. As mentioned above, the opening time of the metal blade determines. Now many cameras are controlled by the camera's own computer chip. In some cameras above semi professional level, the camera still needs to be manually operated, mainly including the following: slow and fast, 1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000 seconds. In some more professional cameras, there are also faster door speed settings that are longer or shorter than these. Similarly, every time the shutter speed jumps up or down, the amount of exposure will be doubled or halved. [Relationship between aperture and shutter] The larger the aperture is, the shorter the relative exposure time is required (not counting under special conditions). There are many different shutter speeds and apertures that can be matched to get the same exposure value, but the exposure effect may not be the same, because there is also a problem of depth of field, which will be discussed later. The lens with is called "fast lens" because it can be matched with a faster shutter speed. （2） Camera operation mode Now some low-end models, also known as home models, are mostly full exposure point machines. There are two basic exposure modes: manual mode and semi-automatic mode. This is basically the same as traditional cameras. [Manual Mode] Not all cameras can. When selecting manual mode, you can ignore the combination parameters prompted. You can automatically select the aperture and shutter value. How to make an ideal exposure depends on the specific situation and personal preferences at that time. Of course, you need to practice more. [Semi automatic mode] Many cameras provide at least a semi-automatic exposure mode. Generally, one of the aperture and shutter speed is fixed first, and you can adjust the other one. Then came the mode or shutter priority mode, which we often refer to. The difference between the two modes is that the aperture is selected first or the shutter speed is selected first. [Situation mode or special theme mode] In fact, this mode is very popular now. A knob is set in many mid-range so-called semi professional cameras above canon G3, G5, and olympu730. We can use landscape, sports, and people modes without manual steps. The landscape mode generally takes into account the depth of field, the motion mode focuses on the relatively high shutter speed, the portrait mode focuses on the appropriate large aperture, etc. The exposure combination determined by the computer chip is often more ideal than the decision of some beginners.
