How Fast Is Your Zoom?

Often, lenses may be marked with a range of f-stop numbers, such as f3.8-f4.5, which means that it has an aperture of f3.8 when set at its greatest wide angle, and f4.5 when shooting at its maximum telephoto. The lower the number, the faster the corresponding shutter speed. Most digital camera zoom lenses are on the slower side, like f3.5 or f4.5. Faster lenses, like f2 or f2.8, are great for shooting in low light; the downside is that they're generally bigger and heavier (they have more glass) and often cost more.

Using Your Zoom Lens Creatively

Besides moving your subject closer or farther away, your camera lens also changes perspective as you zoom. At telephoto, the foreground and background will appear much closer to each other, as though they're compressed. But at a wide angle, the foreground and background will look like they're far apart. Wide angle can distort close-up subjects in interesting ways.

Try this experiment: Stand with your main subject about 6 to 8 feet from your lens. Then, without moving closer or farther from your subject, take a series of pictures using different zoom settings, from wide angle to telephoto. This one experience will give you a more intuitive understanding of your zoom lens than any listing of numbers. As you get to know the characteristics of your zoom lens, you will gain more control over your photography and have even more fun with it.