• Capturing Fireworks
• Illuminating flash guide numbers
Q) I thought I’d try to experiment with taking pictures during the 4th of July fireworks displays this year. A friend thought I should use film to do this. I’m thinking that I should be able to use my digital SLR. Who’s right? And what’s the best way of photographing the fireworks display?
Via the Internet
A) It’s a good time of year to talk about photographing fireworks. Either film or digital is capable, but digital will allow you to immediately see what you’ve captured. Because you don’t have much control over composition, instant review is a big help.
Some tips for shooting on the Fourth of July:
• First, you might want to check out when other displays may be happening nearby. If they aren’t all on the same night, it can be useful to practice by going to a couple of different exhibitions.
• A tripod is a must. Exposures will be long, so handholding will just create blurry flashes of light.
• As far as lenses are concerned, you don’t need a telephoto lens unless you’re shooting from a long distance. If you have a zoom lens that goes from a medium wide-angle to about 120mm, that should work fine as long as you’re at a normal viewing distance. If you try for a telephoto lens, you can certainly fill the frame with explosions, but you need a lot of luck to ensure that the display is in your frame. A zoom will help you adjust for different sizes of displays.
• A remote control or shutter release cable is also a good idea. It will help to keep the images sharp.
• Lastly, you need a large, empty memory card.
If you think about what you’re trying to do, it can sound a bit daunting. You’re composing an image in the dark, not knowing where your subject will be, not knowing what light level you’ll be dealing with, and not having anything on which to focus. That’s why I recommend a big memory card.
So now that you have the tripod, camera, lens, cable release and memory card, what next? I recommend showing up early and getting a good spot—good advice even if you aren’t taking pictures. If you’ve never been to the display before, it’s important to find out where the bulk of it will be shown. I’ve had good luck by looking for the pyrotechnic equipment and then asking any emergency personnel I can find to verify the best vantage point.
When you start looking for a spot, consider what will be in the background. If streetlights or some other illumination might be in your shot, look for another angle. Also look for tree branches or power lines that might ruin your shot. And you don’t want to be right in front of an aisle where people might walk in front of your shot. Think about all this now because it will be difficult, if not impossible, to move once the show starts.
Also, consider the wind. A lot of smoke is produced, and if you’re downwind, you might have a difficult time during some parts of the show. If you’re upwind, the smoke will drift out of your view and clear the way for good contrast. If you’re at right angles to the wind, the smoke will drift out even faster.
Once you’ve found your spot, I recommend setting up your tripod right away. I’ve found that it helps to prevent people from blocking your shot with portable chairs, etc. The tripod doesn’t have to be extended much-just so you can operate the camera comfortably and review some of your shots.
Exposure should be manual because using automatic exposure will usually result in overexposed images. Choose a low ISO setting to reduce noise. Aperture should be around ƒ/11, though you can try ƒ/8 or ƒ/16. In practice, you’ll need to adjust both your aperture (to get the right exposure) and your shutter speed (for the amount of fireworks in the shot). With a remote shutter release, you’ll set your camera on Bulb and then manually trigger the shutter. Exposure lengths can vary widely (from one to four seconds or more).
Okay, so you’ve set up your camera, and the show is about to begin. You’ve set your aperture to ƒ/11, attached the shutter release cable, and your camera is set to Bulb. What now? You need to make sure your focus is correct. While you could just rotate your focus ring over to infinity, that might not be the right focus. You should use the first couple of fireworks bursts to verify your setup. First, look through the viewfinder (or LCD if you have a live view) and see if your framing is in the right area, then try to tweak your focus. This might take a few minutes to figure out.
Then, take your first picture by snapping the shutter just as the fireworks shell begins to slow down (watch the faint spark trail) and make your best guess of when it will explode. Hold the shutter open for about two seconds. Then, review the image carefully. You’ll be tempted to keep taking shots but, believe me, you’ll be disappointed if you don’t check your first shots.
Take a look at the histogram and make sure your aperture setting isn’t underexposing or overexposing. This might change depending on the explosive power of the shell, and sometimes white is white. You might adjust your aperture several times during the show. Next, zoom in on your image and make sure you have good focus. This is critical: Don’t try to evaluate this without magnifying the image. Remember that you’ll be doing this in the dark, so make sure you know how to operate these functions well.
While you’re looking at the magnified image, make sure you’re not seeing any camera shake. There will be blur because the sparks are moving, but that will look different than camera shake. Once you’ve evaluated your first image and made adjustments, you can start shooting. Play with different lengths of shutter speed. If you want to capture multiple bursts in one exposure, bring a piece of black cardboard to cover the lens. This way you can leave the shutter open longer and cover the lens a few times to capture several explosions. If you use this technique, be careful about noise build-up on the image sensor.
Consider shooting vertical as opposed to horizontal. While it can be a bit more difficult to shoot this way, there are some opportunities to capture the trails leading up to some of the bigger shells. If the display is near some interesting buildings, you should consider a wider shot to capture the architecture that’s lit by the exploding shells.
Illuminating Flash Guide Numbers
Q) I’m considering purchasing an external flash for my camera, but I’m not sure what the guide number is. Should I really be concerned about it?
Via the Internet
A) Cameras can be heavy, especially when you add a longer lens to them. An obvious key to keeping images sharp is keeping the camera still. Last month, I gave you a way to practice using a light touch on the shutter release. But if you can’t hold the camera still in the first place, a soft touch won’t help.
Simply put, the guide number is a measure of the flash’s strength. To compare the light output of each unit, the guide number or GN specification is used. If you’re concerned about having a strong flas
h that can throw light great distances, then you need to be aware of the guide number.
The GN specification is given with an ISO setting and a unit-of-distance measurement, as in “this flash has a GN of 60 at ISO 100 (as measured in feet).” This allows you to plug the guide number into an equation to determine correct exposure. The formula is: GN divided by distance = lens aperture. “Distance” in this case is the distance from the flash to the subject, not the distance from the camera to subject.
With the flash example above, if you had a distance of 15 feet, the aperture setting would be ƒ/4 (60/15 = 4). From this formula, you can take the simple idea that the larger the guide number, the more powerful the flash. It’s up to you to determine how much power your budget can afford.
Before I close out this issue’s HelpLine, I’d like to thank all of the readers who have sent in questions-keep them coming. If there was enough time in the day, I’d love to answer all of your questions personally. Unfortunately, I can’t, so I apologize if your question has yet to be answered. Please note, however, that I also answer a question each week by clicking HelpLine.