I have a Canon SLR. What is the autofocus blur when taking pictures?

It seems that you are not in focus, and the reasons for not being in focus may be the following three situations:

First, the AF and MF buttons on the lens are common on MF, that is, on manual focusing.

Second, it is particularly related to Canon's concentration. Canon uses contrast focusing. If the contrast is too small, such as white paper in Wan Li and cloudless sky in Wan Li, it is difficult to focus.

Third, it usually takes two cycles for a digital camera to press the shutter, that is, press half the shutter first. At this time, it is focusing, and there will usually be a prompt sound. After hearing the prompt tone, continue to press the shutter, and after hearing the shutter release tone, the whole shooting process is over. This shot will be a contrast, otherwise it may be a paste.

Compare and see what kind of situation it is.