One of the first things that even a beginning photographer learns is that you can concentrate attention on a certain part of the picture in a number of ways. The first way is to literally draw focus to your subject by making it the only “in focus” part of the picture. This can be done “in camera” by adjusting the aperture. The smaller the aperture (the higher the f-stop number), the more depth of field you’ll have, until everything in is in focus. If you open the aperture (make the f-stop number smaller), then you’ll have a smaller depth of field, and the parts of the picture other than your subject are thrown out of focus.
Smartphone cameras have little in the way of an adjustable aperture, so a whole class of apps has grown up that will put parts of your picture out of focus, thus concentrating emphasis on your subject. One of these is Big Lens, by Reallusion.
The first thing you have to keep in mind is that this app will NOT make your photos look as though you actually took them with a small aperture. The demarcation between “in focus” and “out of focus” will not be sharp. Also, those parts of your picture that are out of focus are all the same amount of out of focus. So you can’t have a flower in the foreground in focus, a flower a foot away partially in focus, and the forest behind way out of focus. Even with these drawbacks, there’s a lot to like about the results you can get with Big Lens.
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