Christmas Bokeh and Compression

This is a guest post by Erika Thorness

The other day, I was watching a family take photos in front of a Christmas tree. They were standing directly in front of it. I realized that with a bit of practice, and knowledge, we can really use the lights in the tree to our advantage, and set the stage for a fantastic background for our holiday portraits.

Set Up

I’ve started with a Christmas tree, of course. I placed a seat about 4 feet in front of the tree and placed a cushion and blanket on top of it. It provided a great place to put the baby where the lights would be behind her. Using a seat encourages the subject to be forward, in front of the tree. It doesn’t feel natural to be so far away. The distance you’d like can vary depending on what look you’d like, and what lens you’re using, but for this example, 4 feet is a good starting distance.

Secure the Baby

I shouldn’t have to say this, but just like reminders of not letting babies chew on Christmas lights, or running on train tracks if you are photographing a baby on a raised surface, be sure to have a spotter with a hand on the child!

Lens Choice

I’m using three lenses for this example, a 35mm, a 50mm, and a 135mm. All fixed focal length lenses on a full frame camera. Some Cameras have crop sensors. With a crop sensor camera, the effective focal length will change, but the overall concept is the same. So, play, play, play and figure out what works for your space, and your lens. You’ll want to have your lens as wide open as your lens can go, while still keeping your subject fully in focus. I shot these photos between F/2.0 and F/2.5. A lens that doesn’t open up that wide, like a kit lens, or a 2.8 zoom lens will also work. Just keep your aperture as open as possible.

35mm Lens

With the 35mm lens, I was sitting pretty close to the baby when I took this photo. I shot this at F/2, 1/100, ISO 1600, as you can see how much of the tree is in the view behind the image, and the size of the bokeh caused by the lights in the tree. Small, cute, and festive, but we can do better!

50mm Lens

With the 50mm lens, you can see that the tree fully fills the background. I moved a bit further back, and the baby is the same size. This is called compression. Less of the background is shown the further you zoom in, even when the subject in the foreground is the same size. We are totally using this to our advantage. In this image, the bokeh seems about the same size as with the 35mm lens. It would be larger, than the previous image, but instead of shooting at F/2 I shot at F/2.5, the brightest my 50mm lens will go. The compression won’t change with a change in aperture, but the bokeh does, so keep this in mind if you don’t have a lens that can open up as wide. Your bokeh balls of light will be smaller at 4 feet with a lens that can’t let in quite as much light. You might need to adjust and place your subject further back from the tree and closer to you.

135mm Lens

My favorite! I had to sit really far back to get this shot. I was back about 8 feet. I didn’t move the tree or the baby, I just chose a 135mm lens, shot at 1/100, F/2 ISO 1600. Mom was holding the baby, as I really was out of arms reach. As you can see we are not able to see nearly as much of the tree, yet the baby is the same size, and the bokehed Christmas lights create a much bigger/bolder effect in the image. I really love it.

Takeaway

So, my advice, if you want really bold big bokeh from Christmas tree lights, have your subject move away from the tree. Don’t place them right next to it. Have your lens as wide open as possible (lowest F/stop your camera and subject can handle). Finally, step back and zoom in, using the longest reach you can get away with in your space.