Jul05
Fireworks
Last night was the annual 4th of July fireworks. Photographing fireworks can be challenging. One way is to keep the shutter open for several bursts. To do this set the camera ISO to 100 and the exposure on manual for 20 seconds or so. Manually set the focus to infinity. Aim the camera where the bursts are occurring and record as many as you can. The problem is, unless you are at a location that is very dark, the light of the sky will record and you have fireworks against a blue sky. You may also pick up light pollution from city and building lights. This method will record the streaks the fireworks make in the sky.
Another approach is to photograph individual bursts. Last night I had my camera ISO set to 100, aperture to 4.5, shutter speed to 1/20th of a second and focus distance to infinity. Then I recorded individual bursts. Even this is challenging because you want to get the burst when it is brightest, which generally is right after it explodes. This means you have only a fraction of a second to make a decision to push the shutter button. Fortunately, with digital photography there is no cost to shooting extra frames.
Then, if you have a photo manipulation program such as, Photoshop or Photoshop Elements you can combine the individual bursts into a single image. Import an image, which will be the background layer. Import another image and make it the next layer. There are several ways to combine images, but the one you want is “lighten”. This method looks at each pixel location, on both layers, and selects the “lightest” one. So if one layer has a bright fireworks pixel at a given location, and the other layer is black, the merged image will have the bright pixel. You can continue to do this with as many bursts as you please. While this may not represent the sky at any one instant, it does represent the way I often feel when many bursts happen very close together.
If you have some fireworks pictures from last night, and have a photo editing program, give it a try.
Fireworks