Extreme Zoom Lenses: Pros & Cons Of All-In-One

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All-in-one extreme zoom lenses—those that go from wide-angle to telephoto—offer some solid benefits for a nature photographer who’s on a road trip. They’re lightweight, versatile, easy to pack and carry without needing to have a large camera bag, and thanks to advanced design and manufacturing technology, they offer solid image quality. If your budget or travel requirements limit you to just one lens, a superzoom provides a lot of bang for the buck. To help you decide if one of these multitalented zooms is right for you, let’s take a look at the pros and cons.

PRO: Focal-Length Flexibility
Having a wide range of focal lengths in a single lens obviously is very convenient. A single superzoom may well cover all your needs when you’re traveling or hiking in the wilds. You won’t miss shots because you didn’t have the right lens on the camera when the photo op occurred—zooming to the right focal length is much quicker than changing lenses in the heat of the moment, and it’s often easier than changing your position. Also, these all-in-one zooms give you the ability to shoot a wide-angle landscape and then zoom in on wildlife in an instant. The focal-length flexibility is the strongest single advantage of an all-in-one zoom.”

CON: Not As Sharp
The main downside to all-in-one zooms is that they aren’t quite as sharp at any given focal length as a shorter-range pro zoom or a prime lens of that focal length. Each focal length creates its own aberrations and distortions, and requires its own solutions. It’s tough enough to minimize these problems for a single focal length; to do it throughout a wide range of focal lengths, especially when trying to keep bulk and cost down, is quite a challenge. That the lens makers do it so well is a remarkable achievement, but you should understand that there are limitations, and you’re more apt to see those limitations with today’s high-pixel-count DSLRs or mirrorless interchangeable-lens cameras. That said, the superzooms usually perform better than the typical 18-55mm kit zooms sold with many DSLRs, making them great alternatives or step-up lenses.

PRO: Compact Package
Next to focal-length flexibility, the main advantage of the all-in-one zooms is their compactness. Most measure around 3×4 inches (diameter x length) and weigh 15 to 20 ounces. That’s remarkable considering that they provide every focal length from true wide-angle well into telephoto territory. That certainly beats carting several lenses around when you want to travel light. For a photographer on a road trip, it also means you don’t have a large camera bag in your car tempting would-be thieves. With just a camera body and a single lens, you can easily conceal your gear or carry it with you everywhere you go.

CON: Slower Than Pro Zooms
Being slower, the superzooms don’t let you limit depth of field so much, and they produce a dimmer viewfinder image. Typical superzooms are variable aperture, and their range is usually from ƒ/3.5 to ƒ/5.6 or ƒ/6.3. For example, an 18-250mm ƒ/3.5-6.3 zoom has a maximum aperture of ƒ/3.5 at 18mm, slowing to ƒ/6.3 at 250mm. The minimum aperture also changes as you zoom; for our example lens, that’s ƒ/22 at 18mm to ƒ/40 at 250mm.

This Article Features Photo Zoom

That’s in contrast to shorter-range pro zoom lenses, which typically have ƒ/2.8 maximum apertures and maintain that maximum aperture throughout their focal-length range. This makes the pro zoom much better for shooting in dim light, especially at the longer end of its range. An ƒ/2.8 aperture lets in twice as much light as an ƒ/4, and four times as much light as an ƒ/5.6, for example. Faster lenses also provide a brighter SLR viewfinder image for composing and visual focus confirmation, and faster lenses help considerably with autofocus. And a wider maximum aperture means you can shoot with less depth of field, which is necessary for selective-focus images of flowers and such at the long end of the focal-length range.

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We’ve pictured several popular models. 1) Canon EF 28-300mm ƒ/3.5-5.6L IS USM; 2) AF-S Nikkor 28-300mm ƒ/3.5-5.6G ED VR; 3) Sigma 50-500mm F4.5-6.3 APO DG OS HSM.

If your shooting style usually requires maximum depth of field and you don’t rely on fast autofocus, you may not feel the effects of a superzoom’s slow maximum aperture too much. However, if you need top autofocus performance, the all-in-one zoom won’t be an ideal choice.

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4) Canon EF-S 18-200mm ƒ/3.5-5.6 IS; 5) AF-S DX Nikkor 18-200mm ƒ/3.5-5.6G ED VR II; 6) Sigma 18-200mm F3.5-6.3 II DC OS HSM.

PRO: Good Close-Up Capability
Most all-in-one zooms will focus down to under 20 inches, close enough to provide 1/4 life-size images at the image plane when set to their longest focal length. That’s not true macro territory, which would be 1:1, but it’s close enough to do some amazing flower and insect portraits.

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7) Sigma 18-250mm F3.5-6.3 DC OS HSM; 8) Sony AF DT 18-200mm F3.5-6.3.

CON: Not True Macro Performance
Besides being able to focus down to 1:1, true macro lenses are optimized for close shooting distances. As “generalists,” the all-in-one zooms aren’t as sharp as true macro lenses at close range. Superzooms are able to focus down to 20 inches or less when set at their longest focal length, but many of them also shorten the actual focal length as they’re focused at close range: an 18-200mm zoom set at 200mm and focused at its minimum focusing distance actually may have a focal length of 140mm or so. This isn’t really all that significant of a problem. You don’t get the magnification you might expect from 200mm at 20 inches, but you still get that 1/4 life-size or better magnification, and with it, good close-up capability.

PRO: Relatively Inexpensive
Many of the all-in-one zooms sell at estimated street prices of under $600, some for as little as $300. That makes them great deals in terms of cost and versatility. If you were collecting a number of lenses to fill the same 8x or greater superzoom focal range, you easily could spend a couple thousand dollars or more—much more. The superzooms incorporate low-dispersion and aspherical elements to reduce the adverse effects of aberrations and distortions, and do a remarkably good job, considering their cost and focal-length range. Their price makes a superzoom a very attractive option for many photographers.

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CON: You Can’t Expect A $500 Lens To Perform Like A Pair Of $1,500 Lenses
Higher-end lenses feature better materials and construction to obtain better optical and mechanical performance, and those cost money. You’re not going to get the most exotic optical elements and rugged, weatherproof pro construction in a $500 superzoom.

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9) Tamron 18-270mm Di II VC PZD; 10) Olympus Zuiko Digital ED 18-180mm ƒ/3.5-6.3; 11) Sony SEL 18-200mm F/3.5-6.3.

PRO: Save Money On Filters
If you have several lenses, each with a different diameter, you’ll need a set of filters for each sized lens, or a series of adapter rings (which could cause vignetting when used with wide-angle settings). With a superzoom, one of each filter type covers all of your focal lengths. You just need one polarizer, neutral-density, grad, etc., instead of one for each lens you have. Besides the cost savings, using one superzoom in place of several prime lenses or shorter-range zooms means less stuff to keep track of like filters, lens caps and cases.

PRO: Fewer Lens Changes
A wide-range zoom means fewer lens changes in the field—and that means less dust on the camera’s sensor assembly. This is even more important with mirrorless interchangeable-lens cameras, which don’t have a DSLR’s mirror to help deflect incoming dust particles from the sensor.