Nikon D90+ Sleeve 18- 105, want to learn focus tracking, is there a tutorial in this field?

1、? Shutter setting: take the reciprocal of the absolute value of the moving speed of the subject. For example, the speed of a moving object is 60/ km, then the shutter is set to1/60s; The slower the background stream, the better, but the harder it is to shoot, because the handheld camera will shake, and the limit value is 1/6 seconds. ?

2、? Aperture setting: that is, set the corresponding value with the shutter to obtain the correct exposure; The larger the aperture, the better the effect. ?

3、? Focal length and shooting mode and focusing: focal length: telephoto end, mode: M-file or S-file; Focus: Auto focus, (center mode is adopted. Don't use multi-mode and area mode, because the multi-mode camera is always in a dynamic and continuous autofocus state. When the shutter is actually pressed, there is often a time difference that causes conflict and out of focus, and the area mode is useless. ); You can lock the camera by pressing the shutter at a predetermined shooting position, then move the camera to chase the subject, and press the shutter to shoot when the subject reaches the predetermined position. ?

4、? Light selection: (1) Wait until the light conditions meet the requirements of exposure parameters before shooting; (2) When the light is too strong, add a medium gray mirror (a camera filter that can block the light, also called ND mirror); (3) If other lamps use the front light or the front light effect is poor. ?

5、? Choice of subject speed: the speed is between 8- 150km; (Refer to approximate value: I will give a few common speeds, and then I will draw inferences myself. Cars: general roads are 60 kilometers, urban trunk roads are 70 kilometers, and ring roads are 80 kilometers; Motorcycle: 60 kilometers in the urban area and 85 kilometers in the suburbs; Bicycle: most people are 18km, 25km when commuting and 30k m-35km； when riding fast; Pedestrian: normal 7 km, scurrying12 km; 3-year-old children run for a short time: 12 km. When the puppy is playing normally, 12-20km)?

6、? Road surface selection: it must be flat to avoid moving objects moving in two directions. For example, the car is moving forward and there are vertical bumps, so no matter how accurate you shoot, the subject will be empty. ?

7、? On the surface, "shooting after focusing" is shooting a moving object, but in fact it is two concepts with a fixed camera shooting a moving object. The former is that the camera and the subject are in a relatively static state, which belongs to shooting static objects, while the latter is shooting real moving objects, so the set parameters are not applicable to the former. ?

8、? I don't advocate using tripod, because the purpose of this method is not to shoot for the sake of shooting, but to be practical in the future. Can you imagine setting up a tripod when you suddenly have a chance to take a snapshot in the future? Obviously not.

Note: 1. Snapping angle: When the angle between the connecting line between the lens and the center of the object and the horizontal line is 45-90 degrees, it is recommended to press the shutter; 2. The lens must move horizontally from tracking to the end of exposure without vertical jitter. Don't be nervous when taking pictures. When you feel that you press the shutter in a rational and calm state, taking pictures is easier to succeed, and you can't be blinded by luck; 4. Practicing focus chasing is a long-term process, so be patient and persistent.