The use of bokeh in photography is very common. If you are unfamiliar with the term, it is simply blurring out the background of your image to keep the focus on your subject. This is typically achieved by using a wide aperture and fast shutter speed. It's an extremely useful tool and, as we'll see here, you can even manipulate it to create interesting patterns! So, let's get started!
The first thing I did was to set up my small Christmas tree. I didn't put a lot of effort into it because it's going to be completely blurred out anyway. I just wanted to make sure as many of the lights would show up as possible.
Next, I hung my ornament and positioned it. I wanted as much of the bokeh effect as possible. So, I hung it about eight feet or so from the tree and roughly a foot in front of my camera. With the lens I used, that was as close as I could get and keep it in focus.
I decided to go ahead and take a shot to see how the effect was working. I actually like how this looks. However, I wanted to add something more to keep with the season.
Here is my star! I cut out a 4"x4" piece of black construction paper and then marked off my center point. From there, I had to do a little math to see how big I needed to make the star. It needs to stay the size of the aperture. This was calculated by dividing my focal length by my widest aperture; in this case 50mm divided by f/1.8 gave me approximately 28mm. So I marked out 14mm each way from the center point.
Then, all I had to do was place the card in front of the lens! I have heard of people taping the card to the lens, but I found that to be too constrictive. By keeping it loose, you can move it around a little and get different looks!