With focal lengths from 28mm to 200mm (and sometimes more), and everything in between, you can frame a scene exactly as you want it, without having to change lenses or move closer or farther away. This can mean the difference between catching that fleeting moment and missing it while you’re frantically trying to swap lenses. Fewer lens changes also means less chance for dust to enter the camera and settle on your sensor.
Many all-in-one zooms will focus closely enough to produce a 1/4 or even 1/3 life-size image at the image plane, great for frame-filling shots of flowers and bugs. That’s not true macro (true macro lenses focus close enough to produce life-size 1:1 images at the image plane), but it certainly adds to the versatility.
All-in-one zooms (those with a zoom ratio of 7:1 or greater, for our purposes here) also cost relatively little, certainly much less than a set of prime lenses or shorter-range pro zooms that provide the same focal lengths. And, if you use filters, a "superzoom" also can save you money there, too; you don’t need to buy filters to fit several different-diameter lenses.
So, what’s not to like?
Well, for starters, the all-in-one zooms aren’t quite as sharp as short-range zooms or prime lenses. That’s because each focal length has its particular aberrations, distortions and vignetting that need to be sorted out, and it’s not possible to completely correct all of them for an extensive range of focal lengths in a single lens. Corrections that help at short focal lengths can make things worse at longer focal lengths, for example. A big-range zoom lens is a compromise in terms of optical performance.
This doesn’t mean all-in-one zooms aren’t good, just that they aren’t as good at a given focal length as a prime lens of that focal length or a pro short-range zoom that covers that focal length. Computer-aided designs and exotic elements (especially extra-low dispersion and aspherical ones) do a remarkable job of producing surprisingly good performance throughout the focal-length range.
For general photography, especially for a photographer who wants to travel really light or is on a tight budget, an all-in-one zoom is an excellent choice. But, if you use a high-megapixel camera and specialize in huge prints, you’ll probably want to go with higher-end lenses.
Superzooms & Sensor Formats
|Full-frame DSLRs have image sensors the same size as a 35mm film frame, approximately 36x24mm. Most superzooms for these cameras are in the 28-200mm and 28-300mm range.
APS-C sensors used in many DSLRs and mirrorless cameras are smaller, measuring around 23.6×15.6mm. Due to their smaller size, these sensors "see" less of the image produced by a given lens; a lens on an APS-C camera frames like a lens 1.5X that focal length when used on a full-frame DSLR. Put a 100mm lens on an APS-C camera, and it frames like a 150mm lens on a full-frame camera. Thus, superzooms for APS-C cameras tend to be in the 18-135mm and 18-200mm range (equivalent to 28-200mm and 28-300mm lenses on a full-frame camera, respectively).
Micro Four Thirds (MFT) mirrorless cameras (and Four Thirds System DSLRs) use even smaller sensors, measuring 17.3×13.0mm and having a diagonal measurement half that of a full-frame sensor. MFT sensors have a 2X focal-length factor: a 100mm lens on an MFT camera frames like a 200mm lens on a full-frame camera. So, superzooms for these cameras tend to be in the 14-150mm range (providing framing like a 28-300mm zoom on a full-frame camera).
|One of the advantages of a superzoom is that you can compose your scene precisely as you wish from a given spot. Remember, though, that changing the focal length changes the framing and the magnification, but not the perspective. Physically moving closer will "expand" perspective, exaggerating the size difference between near and far objects in the scene, and the apparent distance between them; zooming to a shorter focal length from the same camera position won’t do this.
Conversely, moving farther away will "compress" perspective, reducing the size difference between near and far objects and the apparent distance between them. Again, merely zooming to a longer focal length won’t do this; you could produce a potentially noisier, but otherwise identical image just by cropping a wider-angle shot made from the same camera position to match the area shown in the longer-lens shot.
For maximum expanded perspective effect, move in close and use a short focal length to provide the desired framing. For maximum compressed perspective effect, move far away and use a long focal length to provide the desired framing.
All-in-one zooms also tend to be slower than shorter-range zooms or prime lenses of any given focal length, in both maximum aperture and AF performance. Maximum apertures are generally ƒ/3.5 or ƒ/3.8 at the wide end of the zoom range and ƒ/5.6 or ƒ/6.3 at the long end. These relatively slow apertures mean the viewfinder image won’t be as bright as with faster lenses, you’ll have to use a longer shutter speed in dim light, and AF performance will slow many cameras (most AF systems perform better at apertures faster than ƒ/5.6).
A number of all-in-one zooms have built-in image stabilization, which helps with handheld shooting at the slower shutter speeds (Olympus, Pentax and Sony DSLRs have sensor-shift stabilization, which works with any lens), but slower shutter speeds still limit action-freezing ability. If you specialize in low-light photography or fast-action subjects, you’ll be better off with the faster prime lenses or shorter-range zooms.
One more consideration: As less-expensive lenses, most all-in-one zooms lack the ruggedness and weatherproofing of the more costly pro zooms and primes. This could be a factor if you shoot in harsh conditions, but it’s not a big deal otherwise.
While superzooms won’t be the best choice for every subject or desired result, they’re incredibly versatile and affordable, and give you a lot of compositional flexibility in a compact, lightweight package. If you’re still shooting with the kit lens that came with your camera, a super-zoom is a good next step to expand your system’s capabilities and discover how extended focal length options can broaden your creative options.