What is focus in photography
The definition of camera focus, in simple words, is just making the selected part of the photo sharp. It is closely connected with the notion of the depth of field, as the latter describes how “deep” the focus is and how many “layers” of the picture are sharp and distinct.
There are two main types of focus: manual and auto ones. Technically, to focus on an object, a device must move its inner parts, mirrors and/or a sensor. From the artistic point of view, there may be deep, shallow and selective focus photography, but in this article we are mostly interested in technical details and peculiarities.
Auto focus and its types
Auto focus, as the very term implies, is the process when a cam or a lens adjusts the sharpness automatically, with the help of an in-built motor.
There are two ways to use it. The most popular one — just press the shutter button halfway. Usually after it the cam will “beep” or the grid at your viewfinder will change color. Another way – use a special back button, but be aware that not all the digital cameras have one.
- Single Area AF. Fixes a focus at the chosen object at the set distance. If you approach your model or step back, the focus will be lost. So you’d better use it for shooting stable objects, for example, landscapes or portraits.
- Continuous AF. This mode allows you to keep the selected object “in gunsights”, even if it’s moving. It’s the best choice for shooting sports events or wildlife. To use it, press the shutter button halfway and hold it while following the object, when you are ready, just press it till the end.
- Multi-Area AF. You may choose which areas must be in focus. The exact quantity of these points depends on the camera model. Some devices even have special “Eyes-focus”, “Group-focus” and other modes.
- Predictive AF. Sometimes objects are moving so fast that you just can’t “catch” them in the focus, as there is still a time lag between a shutter release and actually taking a picture. This mode considers it and focuses not on the object, but on the place, where it will be in a sec.
To focus your camera manually, just adjust the ring on the lens till the image in the viewfinder is clear and sharp. Manual focus camera mode may come in handy if there is poor lighting or you shoot something bleak, without a distinct contrast, so the gadget can’t catch a focus automatically.
Recompose your photo. Cameras tend to focus on the central part, which is not coherent with the Rule of Thirds. To avoid it, just press the shutter button half-way when the needed object is at the centre of the frame, move your cam to recompose the image while holding the button and hit it the whole way down.
By the way, you can also crop the taken photo to make it conform to the rule.
- Choose where to focus. You may not only focus on quite unconventional zones, but also de-focus your photo, adding some Bokeh effect. Be creative!
- Don’t forget about post-shooting editors. While the correct focusing is half the battle, you still have to adjust white balance, contrast and other parameters to make your picture just perfect!