Friday, December 9, 2011

Shoot for the Star...bursts!

Greetings, Hohenfels, welcome to Hohenfels Volks, THE place for our place. I hope the week has been gentle to all.

How are the bubbles coming? Are they taking form, or are you stuck? Have no fear; your vision can carry the day. Just stop to see the light and you’ll come up with a winner.

Jennifer, who’s blog can be found here, liked a link the other day that I found very interesting. Click it Up a Notch is a great source for learning photography. The blog has some great tips for beginners and anyone looking to improve their images, and is backed up with some wonderful photos. Check it out!

The post she liked and I read was 5 Tips for Shooting Christmas Lights. Nice post, nice pics, cool blog. I decided to do a post about starbursts. They make for some awesome additions to a good composition.

The first thing to understand about starbursts is that they are caused by light diffraction. The light bends as it passes the blades in your diaphragm, which changes the way the light hits your sensor. Light that is brighter than the surrounding areas tends to streak as it passes over the blades, creating starbursts. We all love to see some of them in our images, especially nighttime and Christmas shots. The actual rays or spikes in the starburst are caused by light passing over the blades where 2 of them come together. The more blades you have the more rays you’ll get. The funny thing is that even numbers of blades cause the number of rays to match the number of blades. In a lens with an odd number of blades, the number of rays is actually twice the number of blades. I’m not a physicist, so I can’t explain it. You can get decent starbursts even at apertures like f/8 or f/11 depending on your focal length. Most people tend to shoot for them at f/22 and sometimes higher. The shorter the focal length you use, the smaller the aperture is at the same f/stop, and the more likely you are to get good ones, at least that’s the theory.

Another important thing to remember, if you want to print your photos at 8x10 or larger, is that over about f/16 on an APS-C sensor you start losing sharpness in the details. It’s a trade off, so think about how you wish to present your pic.

Here are some photos that show the effect and the difference in blade count between 2 lenses.

ISO 100, f/16, 30 seconds, 200mm
If you count the rays on the large light on the bridge, you'll see this lens had 9 blades. This shot and the next one were taken in Wurzburg with an old 300D from Canon.

ISO 100, f/22, 30 seconds, 165mm
You can see a slight drop-off in sharpness, but more pronounce rays.

ISO 100, f/16, 10 seconds, 18mm
Notice 6 rays emanating from the bulbs. The lens had 6 blades to the diaphragm.

ISO 100, f/8, 20 seconds, 55mm
The starbusts here are minimal, and slightly soft. At a shorter focal length, perhaps something better might have appeared. This was taken with an old Canon 300d in Hohenfels, as was the previous photo.

There is another way to get starbursts. You can buy filters for your lens. You can choose from any number of rays and they apply the effect equally to all lights. That takes the fun out of it, but they could come in handy.

Here in Hohenfels, and in the towns around us, there are so many places that light up a tree or wreaths. Get out there and you'll find something to shoot for the starbursts! You don't even have to leave your house during this time of year! Try it on your tree, you'll see some cool things happen.

Remember to cast your vote for next week’s theme. I hope to see more than the 4 votes we have right now. 19 Volks like us on Facebook, I hope 19 will vote! Are you thinking of your bubbles? I hope to get something in if time allows me to shoot today! Remember to get your pics posted at the Hohenfels Volks Facebook page. Of course, commenting on both Facebook and here is always appreciated, too!

No comments:

Post a Comment