Friends who want to buy digital cameras and DV recorders will always see advertisements from merchants: how many times the zoom, what anti-shake, etc. In order to prevent friends from being fooled by merchants' gimmick advertisements, I will explain in detail the zoom and anti-shake of digital photography equipment.
When it comes to zooming, friends who have played with film cameras know that the focal length of the lens is adjustable, which can be reduced to short focal to obtain a wide-angle effect, or it can be pulled into a telephoto for long-range shooting to achieve the effect of the telescope. The function of
is ported to digital cameras and is divided into digital zoom and optical zoom . Merchants often make the digital zoom very large. Friends who don’t understand think that digital zoom seems to be high-tech and very high-end.
In fact, digital zoom is to take part of the image on the photoreceptor for calculation, insert the calculation pixel, and enlarge it. The higher the multiple, the blurry the image and the lower the sharpness.
optical zoom is the real zoom. You will find that cameras with real optical zoom ratio are very expensive because it uses micro motor to change the focal length of the lens, which is high cost, good effect, and will not lose clarity. It is often used in advanced SLRs.
For general card cameras, the lens focal length is fixed. The boastful zoom can only be digital zoom, and it cannot be optical zoom. Some of them are not even very good at focusing, and the focus fails from time to time, and the photos taken are blurred.
After talking about zooming, let’s talk about the anti-shake function. Please note that the digital anti-shake or electronic anti-shake of the advertisement is actually to increase the sensitivity and shorten the photosensitive time, that is, to increase the shutter speed. It is not the real anti-shake, it will increase the noise of the shot screen and the effect will be worse.
The real anti-shake is optical anti-shake , especially the current five-axis optical anti-shake. It makes the photosensitive device CMOS in a suspended state. According to the camera shake received by the gyroscope sensor , the photosensitive device does the opposite action, offsetting the impact caused by camera shake or DV shake.
Five-axis optical anti-shake, that is, the photoreceptor can move left and right, up and down, and can also pitch up and down along the X axis, swing left and right along the Y axis, and rotate left and right along the forward Z axis, which is exactly the five axis. Correct the impact of shooting jitter in all aspects.
It is the real anti-shake, so machines with this anti-shake function are also very expensive and the shooting effect is also the best, such as the Sony HDR-CX680 camera. Whether
can shoot good works depends on people. When there was no anti-shake function in the past, excellent works were still taken on a tripod. Now the added anti-shake function can be more convenient for users to use. However, the anti-shake function also has its limits. If you shake it hard, it will still not be corrected.
