By choosing a high Quality-setting you will reduce the amount of compression applied to your images. JPEG compression degrades image quality and can even introduce artifacts into your image. This is a particular problem for this subject matter because compression artifacts are typically found in areas of high tonal and color contrast, like the bright colored light of fireworks bursting against an inky black sky. Less compression means fewer image artifacts and ultimately better image quality. Unless you have a top-of-the-line pro DSLR, don’t expect to be able to take photos of fireworks with a digital camera in RAW. Your camera will likely take too much time to write the image to the card and you’ll miss getting some pictures.
Which way should you hold the camera? Typically, you’ll be better off with a vertical format rather than horizontal. After all, the trail of a skyrocket is usually upward and not very wide. However, a final decision about the frame you use will also depend on the size of the crowd viewing the event, your position in that crowd, and the number of spots from which the fireworks will be deployed. For example, in New York City, Macy’s Department Store has sponsored the Fourth of July fireworks display. The shells are launched from a string of barges in either the East River or Hudson River that’s almost a mile long. That means you might be able to fill a horizontal frame with six or more bursts at one time, so it would probably be a better choice than a vertical one.
Regardless of your camera, once you’ve worked out the shutter speed/aperture/ISO combination, the key to success is a solid platform to hold the camera motionless during the time the shutter is open. This is pretty much a requirement for all time-exposures or shutter speeds slower than 1/30 of a second. Obviously, the best platform of all is a tripod. It provides a solid, easy-to-carry base on which to hold the camera motionless during the exposure. It also allows you to easily position the camera at the proper elevation. All DSLRs and almost all point-and-shoots have a threaded opening on the bottom that permits you to attach the camera to a tripod.
Typically, noise/grain is not a problem in this type of image. We recommend that you use ISO 200, or 400. The important point is that you don’t need a very fast ISO; in fact super-fast ISOs may overexpose the firework display. Very slow ISOs – for example, ISO 100 – may not be sensitive enough to capture the display. (Remember, while your shutter will be open for a second or two or more, the actual appearance of the “rockets red glare” will last only a fraction of a second in any one place.)
What aperture should you use? Your f-stop will be based on the ISO you select.
You might think that because the sky is so dark you need a wide aperture. Just the opposite is true. Remember, your objective is not to record the dark sky except as background. You want to record the intensely bright streaks of color. Were you to use a wide open aperture during your time-exposure, you would probably overexpose the colors. Result: They would “burn out” and lose coloration. To intensify the color, therefore, use a smaller aperture like f/8, or f/11, or even f/16. As with your choice of shutter speed, you will have to set your aperture manually. Which you should use depends upon your digital camera’s ISO setting (or the speed of your film), and the intensity of the color bursts. We suggest you bracket your shots, using different apertures.