Regarding the question of the use of SLR, Xiaobai asked a question about the use of SLR

I don't know what brand of machine you use. If it's a Nikon, check if one of the AF MF switches on the top of the lens is placed on the MF manual focus side. Some advanced cameras also have a rotary switch at the bottom of the front lens side (left-hand side) to set the focus status, and if you accidentally touch it and change to manual focus, you may not be able to autofocus.

Canon's only has a selector switch on the lens.

Check to see if the switch of your AF MF is on the MF (the switch is probably somewhere in the front of the fuselage). If it's MF, you dial it to the AF and try again. If it doesn't work, then there's something wrong with the machine.

It may be that you have inadvertently toggled the manual autofocus button on the camera body or lens.

Of course, the SLR chooses Canon, Canon EOS60D is recommended, and the machine is a good choice for photography enthusiasts, enthusiasts, and travelers I prefer the 60D megapixel resolution rotating LCD screen, the new control dial, and the in-camera RAW processing, creative filters and other functions, these functions are the first time to appear on the EOS series of machines, which can make users more handy, and can improve the flexibility of creation The configuration cost performance is good

When you say "shutter speed is within the safe range", you don't need to wait a second or two to move the camera!

DSLR cameras use a mechanical shutter, and the shutter curtain is already imaged into the camera after the shutter curtain is opened, so you can move the camera or take the next shot as long as you hear the shutter sound when taking pictures, so there is no need to wait. The small DC usually uses an electronic shutter, and there will be no mechanical sound after pressing the shutter (if you can hear it, it is only a prompt sound), and its light sensitivity is not high, resulting in a slow shutter speed, so the camera may still be imaging within a second or two after pressing the shutter, so you have to "wait a second or two before moving the camera".

Whether the background can be blurred when taking a photo depends on three conditions: first, the length of the focal length of the lens, second, the size of the lens aperture, and third, the distance difference between the lens and the subject and the background. To put it simply, you can usually get better bokeh by shooting with a telephoto, wide-aperture lens and shooting as close to the subject as possible.

Although the 18 55 lens you use is not a telephoto lens, and the aperture is not wide enough, the minimum focusing distance of this lens is very close, in meters, as long as you use a 55 focal length when taking photos, open the aperture to the maximum (and try to get as close as possible to the subject of the portrait, and pay attention to the distance between the portrait and the background, you can still get a certain bokeh effect!).

1. When shooting in normal light, the shutter generally works for a very short time, generally more than 1 60 seconds. Therefore, when the shutter is finished, you can move the camera immediately, and when the shutter is slower than 1 60 seconds, you can use a tripod, increase the sensitivity, etc.

2. The larger the aperture used, the more obvious the effect of background blur.

You don't have to wait a second or two, you just don't move when you open and close.