Quick, what does this photo tell you about the lens I’m using?
Don’t know? Click on it to zoom in if you need to.
Still don’t know? Here’s a hint. Count the beams on the starburst reflecting off the sequin. That sequin, by the way, belongs to acclaimed Austin actress Gina Houston. And she’s standing next to my husband!
That starburst has 8 rays. And guess how many blades are in my lens? That’s right – 8.
Curious about why that’s important? First, let’s talk about what a blade does inside your lens. Think about your aperture – we make it large to let more light into our photo, and small to let in less light. A series of blades moving around the center of your lens actually controls the size of this opening.
I’m trying a new type of graphic to illustrate this. I hope it works for you! It’s a super short video, and you probably need to have QuickTime installed in order to see it. Press the play button to re-run it.
Can you see those blades moving in and out? That’s what happens as you change the f/stop on your camera. And if you’ll notice, the aperture opening isn’t always perfectly round – it’s more of an octagon. The rays visible in starbursts are caused by light slipping through these blades at the angles on the octagon.
That’s why the number of beams corresponds to the number of blades. In general, if you are shooting with a lens that has an even number of blades, you will have that many rays. If your lens has an odd number of blades, double it to find out how many rays your starburst will have.
How do you determine the number of blades in your lenses? Look at the manufacturers’ specifications. My 50mm f/1.2 is the one I used in the image above – it has 8 blades. The Canon 50mm f/1.8, on the other hand, has 5 blades and will make a 10 point star.
Quick Digression to Talk About Bokeh
If you are going for bokeh, or background blur, this is one of the reasons why the f/1.2 is better than the f/1.8. Five blades will give you pentagonal bokeh that looks a bit more jagged. The 8 blade lens will produce bokeh that is closer to a circle and more able to produce that creamy, buttery look we go for. In the photo below, you can see that the bokeh on the candles in the background isn’t perfectly round, even with the f/1.2 lens.
Back to Starbursts
What is the best way to capture them intentionally in your photography? My starburst in the shot above was not at all intentional, for the record.
- Your first step is to shoot with a medium to small aperture size (a medium to large f/stop number). I shot on f/8 for the sequin photo above.
- Don’t go too small on the aperture however – sometimes image quality isn’t great if you are stopped all the way down.
- Make sure there is good contrast between the light and its background. Trying to get a starburst around the sun if your sky is blown out isn’t going to work – there won’t be enough contrast between the white sky and the color of the sun.
- Become familiar with the number of blades in each lens you own – sometimes you might want to maximize rays, other times, you might just want a few.
- You’ll need light shining pretty directly at your camera for this – I used a flash in the photo above and it reflected right off that sequin back to me.
- With the sun, I find that good starbursts often appear when the sun is partially blocked by something.
- Chrome and windshields are all a good place to grab starbursts. There are several tiny starbursts in the image below.
Have you guys noticed that I love knowing why things happen in camera? Why starbursts happen. How noise is created. Yes, I am geeky. But I am constantly amazed at how much these tiny little cameras can do for us if we know their every nook and cranny.
So that wraps up this tutorial on how to capture starbursts in your photography. If you have any tips I didn’t mention, post them in the comments!