Riding on the coattails of the last post about Christmas lights, I thought it was an appropriate time to bring up a fun way to play with aperture.
First, a refresher on aperture: Aperture is the diameter of the circular hole through which light travels through a lens. By changing the size of this opening you can affect how clear an image appears by increasing or decreasing the image’s depth of field.
If that’s confusing, just think of this example:
Say you have a person standing in a field and you want a picture of them. In the background of the photo is a forest. If you have an aperture that is wide open, that forest will most likely be out of focus while your subject is nice and crisp. How well that out of focus area looks is called bokeh (a fun Japanese term that just means background blur quality).
Changing your lens’ aperture so that it is not wide open is as simple as increasing the aperture value from something like f/2.8 to f/16. The smaller the number, the larger the aperture and visa versa. However, changing your lens’ aperture from f/2.8 to f/16 means that that same forest that is in the background is now more in focus than when at f/2.8.
When you use a smaller aperture, small circular blades come together inside the lens to create a smaller opening for light to travel through.
So, the point of all this is ... aperture is generally a circle.
Now let’s change that to create images like the one attached to this post.
It’s supremely simple.
Take a piece of paper, cut a shape into it that is smaller than the front lens element of your camera. Use a wide open aperture and make sure your focus is shifted so that the image is out of focus (almost entirely). Put that piece of paper in front of your lens before you take the photo and your bokeh will take the shape of whatever you cut into the paper.
Like I said: neat.
The shape of the hole you cut into the paper becomes your aperture so have fun with it. I chose a heart shape because I’m a die hard romantic. You can try snowflakes, diamonds or anything else you fancy.
Have fun and have a merry Christmas!