If you buy a SLR now, you should basically consider Nikon and Canon. Judging from the number of lens groups and the number of friends around you, they are well-deserved industry leaders.

I use canon myself. Of course, I'm not saying that Nikon is not good. It depends on everyone's preference. After all, Nikon and Canon have very different body shapes and different control methods. This needs to be experienced by yourself. There will always be their own tendencies.

Nikon's machines, D90 and other mid-range and above models have body motors, and AF-S lenses have motors if they are lenses, so Nikon's low-end bodies need to focus manually when they encounter lenses without motors, so they cannot focus automatically. Canon's full range of cameras have no motors, but all lenses have focusing motors, so both the camera and the original lens can achieve automatic focusing, and some sub-factory lenses can only focus manually. This is not a problem of Nikon Canon, but a problem of the compatibility of the lens of the sub-factory. Choosing a brand needs attention, but it does not mean that Nikon is not as good as Canon.