Today, I will tell you the differences between AF and AF-S lenses, in this article. Autofocus, or in other words, automatic focusing allows you to focus on the subject without making any physical effort in the form of “twisting the focus ring” or “trying to determine by eye whether the object is in focus”. With the advent of autofocus, the everyday life of a photographer has become much easier and more fun. Yes, many will disagree with me, and will say that all the romance of the shooting process has disappeared, well, okay, let all those who disagree romantically focus their hands.
Nikon began producing lenses and cameras with autofocus (AF in the future) in 1986. All lenses that had autofocus were marked – AF (autofocus).
The mechanism of AF operation is very simple, since in the 86th year no one dreamed of a digital yet, the autofocus was mechanical. The process was as simple as a door, a gearbox was installed on the lens:
and the camera contains a drive:
the camera determines the required distance to the object, the drive rotates the gearbox and voila - autofocus. The people call this method of focusing "screwdriver" (i.e., there is a “screwdriver” in the photo).
Examples of camera body with a “screwdriver”: D50 / D70 / D80 / D90 / D200 / D300 / D7000 / D700 / D3 / D4.
AF-S (Autofocus Silent / Quiet Autofocus). Lenses of this type have appeared relatively recently. They focus much quieter (some are almost silent) and much faster than AF lenses. The difference lies in the fact that the drive is already in the lens, and the camera only sends signals through the contacts:
The drive is already adjusting the optical scheme to the required distance. In general, it doesn't matter how it's done, but the result is fast and quiet autofocus.
Now about the main thing, Nikon has made a commercial division between its digital cameras. What is the division? And here is what, starting with the release of the budget SLR camera D40, all budget DSLR options from Nikon are produced only with AF-S focusing, i.e., they are all without a “screwdriver”, namely this: D40 / D40x / D60 / D3000 / D3100 / D3200 / D5000 / D5100.
Important: AF-S works on all Nikon digital cameras, so you don't have to worry about autofocus, but for AF lenses to have autofocus, you need a carcass with a “screwdriver”.
Nikon is profitable, they end up making money on new lenses, i.e., all new DX lenses are in demand by the niche of people with budget DSLRs. For example, you have a D5000 and want to buy a portrait lens, but the trouble is that on a cheap 50mm f / 1.8 AF ($ 150) you will not have autofocus, so you will need to buy either a 35mm f/1.8 AF-S (250 $) or 50mm f/1.4 AF-S (450 $). That's how my dears, if you want autofocus - pay money. In general, this is not a problem, all new lenses are worth their money, and your costs will not be in vain, but still, I would like to use a “screwdriver”…