It is the same as a auto target function in a shooting game, though I assume that this refers to a camera..
In the world of photography, I would say that it takes whatever pi…cture that is front of you, and balances it out with the best zoom that it has. (MORE)
Autofocus works in one of three ways: .
Infrared light reflects off the subject and back to a photocell, and a computer calculates the distance based on the length of time …it took for the light to travel out and back. A motor then focuses the lens. Limited range. .
A transducer emits and receives ultrasound, instead of light. Everything else works the same. This was popular some years ago, but has been supplanted by contrast focusing because it did not work at longer ranges or through glass (such as a window pane). .
Most common now, and most precise, software in the camera adjusts the focus by means of an electric motor until maximum contrast of the image is reached. A poorly-focused image has fuzzy edges, therefore lower contrast, than a sharply-focused image. This has the advantage of working at any distance, through all transparent media, and facilitates the use of interchangeable lenses. The disadvantage is that it requires supplementary light to function well in dim situations, such as indoors without flash. This can make it somewhat slower than the other two methods. Some cameras have built-in supplementary light using LEDs, and others use a preliminary flash. Professionals prefer to focus by hand in difficult situations when time permits, and some turn off auto-focus entirely except for special situations like fast sports. Even then, pre-focusing can render good results. (MORE)
The advantage with auto focus over manual focus, is that it usually is much faster in focusing correctly. Imagine that you are going to take pictures of jogger running towards… you. Focusing correctly on the runner while he is coming towards you with out auto focus is very hard. However an very experienced photographer with manual focus might manage this scenario also. While auto focus is desirable in many situation, there are situations where manual focus gives better control. The photographer should try to master both techniques. On a single lens reflex camera, it's essential to have a good viewfinder so you can see where the focus point is. (MORE)
No....it does not have a built in focusing motor (AF-S in Nikon terms)..
In fact I'm selling mine because it won't auto focus with other DSLR cameras (even after servicing) t…hat don't require AF-S. ( But it does work great with manual focus). (MORE)
It makes the car have that "extra gear" which allows you to cruise the roads with a 4th gear rather than have only 3 gears without overdrive THERE IS A BUTTON ON THE SHIFTE…R, UNDER THE "t" HANDLE. IT'S "PUSH ON- PUSH OFF" AND THERE IS A LIGHT ON THE DASH, BY THE ENGINE LIGHT THAT INDICATES WHETHER OR NOT IT'S ENGAGED. I WOULD RECOMMEND "OFF" FOR LOCAL DRIVING, IT KEEPS IT FROM UPSHIFTING AND DOWNSHIFTING AND DRIVING YOU NUTS. (MORE)