Pictures By Jean Roberts
Zoom can be simply about getting closer to the subject – like getting a good shot of a bird on a garden feeder or getting closer to the action at a sporting event. There are several important affects of zooming though that are worth bearing in mind.
The difference between optical and digital zoom:
There are two types of zoom, digital and optical. Optical zoom involved the movement of lenses to change how ‘wide’ the field of view is. Optical zoom narrows the field of view in just the same way as a telescope.
Digital zoom is a little different. As a rule of thumb, if the camera you are using does not have a lense that moves or buzzes as you zoom in and out, then you have digital zoom rather than optical zoom. All smartphones (currently only have digital zoom – the lens doesn’t pop out of the camera to zoom in.
Digital zoom is, frankly, useless. Without a moving lense the camera can not ‘see’ extra information by zooming in, it doesn’t work like a telescope. All it can do is take in a smaller part of the image and try to fill in the gaps using computer algorithms. The thing is, computer algorithms are blind and all they can do is guess. As a result the quality suffers. You are better not zooming and cropping the picture later on a computer. Cameras of this type are better for shots where you don’t need to zoom in and can still take good landscapes, portraits or family snaps, so all is not lost.
The effect on focus:
Zooming has a similar impact on the way a picture looks as the aperture. Zooming in and out changes the ‘depth of field’ – the amount of the picture that can be in focus. Zooming will make the depth of field shallower, this makes it easier to blur out backgrounds and draw attention to a particular subject. Zooming out – or using a ‘wider’ angle – will generally make the depth of field deeper and more will be in focus.
The effect on composition:
Composition is also an important element to bear in mind. Choosing to zoom in on a subject isn’t all about getting closer.
Neither of the images below from Jean is right or wrong but they are different expressions of the same subject.
In this first picture we have a landscape. Arguably the house is the subject but the mountain is just as important. In essence the entire scene is the subject of the photo. We get the sense of the insignificance of the building with the landscape looming above.
In the next picture Jean has zoomed in. Not by a long way but there are several different aspects which are interesting. There is, perhaps a greater sense of mystery. We can not see the top of the mountain which can further add to the sense of being hemmed in, the house might be bigger in the image but can somehow seem even more insignificant by not seeing the top of the hills. Zooming in has also pulled the landscape together and as a result the mountain looks steeper and creates a real backdrop to the house. Note than Jean has also place the house on the thirds. There’s no doubt that the house is the subject of the picture.