What is a superzoom lens?
Many of you reading this probably own, or have owned, a lens that is commonly referred to as a “superzoom” lens. These lenses usually cover a very wide focal length range. The most popular superzoom is wide-angle to telephoto lenses, which are produced by the most leading camera and lens manufacturers. Then there are the “telephoto” lenses, which usually start at 70mm or 100mm and usually end at 300mm to 400mm. There are pros and cons to having these lenses.
All-in-one “superzoom” tends to get bad press. Conventional wisdom says that using a more limited zoom range of 4x might be fine, but extending it to 10x or more, the technical and engineering compromises become too great to overcome, and image quality suffers. As a result, many photographers prefer to carry two zoom lenses to cover 18-200mm — usually an 18-55mm pack lens and a 55-200mm telephoto. However, superzoom has an advantage over carrying multiple lenses because they allow you to cover a wide focal range without having to change lenses. This makes them especially useful if changing lenses every five minutes is impractical, or if you’re traveling and want to keep your kit to a minimum.
1. What is a “superzoom” lens?
There is no clear definition of a superzoom lens, but the name generally covers lenses that have a range well above the 3× or 4× of a standard zoom lens, with lenses being 10×, 12×, 18×, or above-considered superzoom.
In APS-C terms, the classic super zoom range is between 18-200mm. Longer super zoom lenses also exist, with long ends of around 300mm fairly common.
With a telephoto lens, the entire range is located at the more extreme telephoto part of the spectrum. These are perfect for nature and wildlife photographers. The optical performance of a wide-spectrum lens usually depends on its price point. The more expensive superzoom and telephoto zoom lenses aimed at professionals and advanced amateurs benefit from higher levels of engineering and better calibration. That means they are optically superior to their consumer counterparts but at a price. They are also likely to have weatherproof seals and stronger construction.
2. Advantages of the super zoom lens
(1) Ultra-low dispersion and aspherical lenses
Superzoom lenses typically display distortion at wide angles and telephoto extremes, and chromatic aberrations at high-contrast boundaries. While using ultra-low dispersion (ED) and aspherical elements won’t eliminate this problem, they do go a long way toward improving overall image quality.
(2) Image stability
Most superzooms have built-in ones. Since most superzooms provide a maximum aperture of only f/6.3 at 200mm, it is very useful to have several shutter speed compensation on hand when shooting in nonoptimal light.
(3) Zoom lock
Because 11x superzoom lenses offer such a wide focal length range, they sometimes suffer from lens creep — when shooting at certain focal lengths, the lens tends to collapse or stretch under its weight when held vertically. Manufacturers are doing their best to eliminate this problem, often by installing zoom locks on these long lenses. While zoom locks by themselves don’t solve the problem, they do allow you to lock the lens to a minimum size (typically 18 mm) for easier and safer transportation.
3. Disadvantages of super zoom lenses:
(1) Smaller sensors
Superzoom lenses have less sharpness per pixel. As a result, you can’t zoom in like you can in a DSLR. If you’re going to print poster-sized photos, a digital SLR is the best choice.
(2) Single lens
A lens that fits all lenses can only do so much. Having portrait and landscape lenses helps get better image quality, while super zoom can only try to match.
(3) Fewer features
DSLRs have some advanced features that super zoom lenses don’t. For example, the wireless remote shutter cable is not available in super zoom.
4. How do we verify the performance of the lens?
There are countless ways to do this, from rigorous bench testing with special test targets to simple field use under the conditions we normally shoot. I’ve done both, but I prefer to start with live testing because that’s the best way for me, at least, to determine if the lens is right for my purposes. I will visit familiar locations and use most of the optics I normally use in these situations to take the same pictures I have been taking for years. This will involve static targets, bright and dim targets, and targets near and far. This allowed me to assess the lens’s ability to lock into focus at long distances and whether it struggled under sub-optimal conditions.
But what I’m saying here is crucial. Sharpness depends on many factors, and when evaluating a lens, the camera operator must have the skills and knowledge necessary to perform that evaluation. This means understanding the many factors that determine the overall resolution. It’s not just about the optics of your lens. Suppose you start by testing static targets. You need a shutter speed that is related to focal length or, crucially, to whatever image stabilization your camera body or lens uses.
All of this assumes that you have good handheld technology and static goals. Even so, the shape of the camera and the balance of the lens is another factor that affects image sharpness, as it relates to stability. I had trouble holding the compact DSLR, and I couldn’t seem to hold it against my face as easily as a side-axle mirrorless camera. Add a long lens to the mix, especially if the lens is light, and makes it harder to get sharp pictures in addition to plenty of light. This is a place where you can bench test the lens because it takes the human element out of it.
What are two drawbacks to a zoom lens?
A zoom lens is usually not as sharp as prime lenses. Another is that the zoom lens is slower. Because the maximum aperture of a zoom lens is narrower, it lets less light pass into the camera.
How does a superzoom lens work?
A telephoto lens works by having the outermost element of a much shorter focal length than the equivalent long-focus lens and then incorporating the second set of elements close to the film or sensor plane that extend the cone of light so that it appears to have come from a lens of much greater.
How far can a 600mm lens see?
Are you asking the minimum focusing distance of that 600mm lens? If so, the answer is about 15ft. If you mean how far away can it shoot distant objects, then that depends on how big they are and how big you want them to be in the final image. It also depends on whether you are using a Full Frame or APS-C camera.