While photographing the snow today, I noticed my auto-focus was having a hard time locking focus. Usually it's quite good and pretty much instant, but today it was occasionally not able to acquire the focus lock.
The reason for that is simple. Snow is a difficult subject to focus on. Auto-focus likes edges and lines, where it can move the focus until the edge is sharply defined, which tells it the lens is focused. Snow typically doesn't have hard edges, at least not at the distance we're viewing it. (If you're locking on an individual flake under a microscope, then you'll find all kind of nifty sharp edges, but most of us don't do that...)
So to try and help the autofocus work, pick a distinct edge or line. Here's an example to show you what I mean. My first instinct was to simply focus on the middle of the log (red square), which was the subject. The focus wasn't doing overly well with that, so instead I moved to the edge (green square). This trick works in all kind of situations, for example in low light, or fog, or any condition where the focus is struggling a bit.
Some cameras will let you move the focus point, for others you may have to get focus, then recompose the shot with the focus locked on. This is often done by holding the shutter down halfway, letting it lock, moving the camera a bit to frame the shot, and the clicking the shutter for the picture. It sounds more complicated than it really is, with a bit of practice it's not hard.
View attachment 4258
The reason for that is simple. Snow is a difficult subject to focus on. Auto-focus likes edges and lines, where it can move the focus until the edge is sharply defined, which tells it the lens is focused. Snow typically doesn't have hard edges, at least not at the distance we're viewing it. (If you're locking on an individual flake under a microscope, then you'll find all kind of nifty sharp edges, but most of us don't do that...)
So to try and help the autofocus work, pick a distinct edge or line. Here's an example to show you what I mean. My first instinct was to simply focus on the middle of the log (red square), which was the subject. The focus wasn't doing overly well with that, so instead I moved to the edge (green square). This trick works in all kind of situations, for example in low light, or fog, or any condition where the focus is struggling a bit.
Some cameras will let you move the focus point, for others you may have to get focus, then recompose the shot with the focus locked on. This is often done by holding the shutter down halfway, letting it lock, moving the camera a bit to frame the shot, and the clicking the shutter for the picture. It sounds more complicated than it really is, with a bit of practice it's not hard.
View attachment 4258
