Remember our first Redoubt Reporter photo contest. Photos must be taken on the Kenai Peninsula with a “Fall on the Kenai” theme. The deadline is Nov. 1. Email JPEGs to: email@example.com. You can find all of the rules and requirements at www.redoubtreporter.wordpress.com/2011/09/07/redoubt-reporter-photo-contest/.
We’ll publish some of our favorite entries from time to time and choose some for the monthlong June 2012 Redoubt Reporter exhibition at the Sterling Highway Kaladi Brothers coffee shop.
By Joe Kashi, for the Redoubt Reporter
Digital cameras are introduced in a blaze of publicity but are soon replaced, mostly because imaging sensors and electronics continue to improve rapidly.
Quality, interchangeable lenses, on the other hand, are mature products. They’re likely to be used for decades on a series of improved camera bodies. Because even the best camera body, with a gazillion megapixels, is only as good as the lens attached to it, it pays to choose wisely.
That’s why we’ve spent several issues examining every type of interchangeable lens. Now, it’s time to complete the circle by looking at some good-quality telephoto zoom lenses, preferably affordable ones. You might say that a once-distant end is in sight. We’ve found some very good telephoto zoom lenses at relatively low prices. It’s worth noting, though, that good lenses require highly precise, complex manufacture, and hence are rarely cheap.
We’ll look first at typical telephoto zoom lenses whose magnification range starts where your kit lens ends. At some later time, we’ll look at so-called travel zooms.
Travel zooms have some practical advantages — they’re small and fairly light. A single travel zoom includes a very high-magnification ratio, 10x or more, spanning the huge range from wide angle through long telephoto. Personally, I don’t like them because their optical quality is relatively low. Encompassing such a wide optical range within a single lens simply requires too many compromises.
Most of the telephoto zoom lenses discussed this week and next can be used with either standard APS-C digital SLR cameras or with larger-sensor, full-frame professional models. Our analysis, though, will compare their performance when mounted on typical consumer and semipro cameras that use a standard APS-C digital sensor.
In almost all cases, image quality improves markedly when you’re using a medium aperture, usually around f 8. Test your own lens, though, to find its optimum apertures for various magnifications.
Zoom lenses with variable or smaller maximum apertures are usually less expensive and lighter, but they’re not inherently optically inferior. Often, a lower-cost, smaller-telephoto zoom with a maximum aperture of f 4 will be as good or better optically than its more expensive cousin with a constant f 2.8 aperture. Even with a smaller maximum aperture, like f 4 or f 4.5, you can still use such zooms for fast action or low-light situations if you double your ISO setting, which works well with good low-light cameras, like the Pentax K-5 or the Nikon D7000 and D5100.
In order to save some space, we’ll list each lens’ weight, price and filter size at the end of our summary description. Filter size is usually a fairly good indicator of relative bulk. Amazon’s current pricing is used wherever possible.
This week, we’ll look at third-party zooms available for most camera brands. Next week, we’ll discuss zooms produced by the six major camera makers.
Tamron and Sigma
Among independent manu-facturers, only Tamron and Sigma make a wide range of telephoto zooms that fit most camera brands. They are usually very well constructed, often optically excellent and frequently better buys compared to brand-name zooms.
Many of the less-expensive telephoto zooms are not image-stabilized, which is highly desirable when using a high-magnification lens. You’re probably better off spending a few hundred dollars more for an image-stabilized lens if you’re a Canon or Nikon user, because those brands do not include the built-in image stabilization.
- Tamron’s 70- to 300-mm f 4-5.6 Di LD lens continues to be the best buy among telephoto zoom lenses. This somewhat older version is light and fairly compact, with excellent sharpness at f 8 between 70 mm and 200 mm, and adequate sharpness at f 11 between 200 mm and 300 mm. It’s probably the best and most economical choice for Pentax and Sony users, whose cameras include built-in image stabilization. (62 mm filter, 15 ounces, about $130 retail). Avoid the older, 75- to 300-mm zoom that some less-scrupulous dealers try to substitute. That older, film-version lens is not very sharp and not suitable for digital cameras.
- Tamron’s newer image-stabilized 70- to 300-mm lens is a brand-new design that’s almost as good as Canon’s comparable L-series 70- to 300-mm f 4 telephoto zoom, but much less expensive (at about $430). It’s significantly heavier (27 oz) and larger than Tamron’s older non-stabilized 70- to 300-mm lens. It’s intended primarily for Nikon and Canon cameras that do not include the image stabilization that’s built into Pentax and Sony bodies. As one would expect, it’s sharpest in the lower half of the magnification range.
- Tamron’s 70- to 200-mm f 2.8 is one of the better choices for high-speed sports photography and wildlife photography under poor light. Optically, it’s an excellent lens, better than some similar offerings from major camera vendors, for a lot less money (77-mm filter, 40 oz, $770). Note that this f 2.8 lens is nearly three times heavier than Tamron’s basic 70- to 300-mm variable aperture zoom.
- Wildlife photographers often need a “big gun” to capture distant animals without spooking them. Both Tamron and Sigma make really high-magnification zoom lenses that reach out to 500 mm. Tamron’s is lighter, more practical and less expensive. Although no affordable 400- or 500-mm lens will provide razor-edge sharpness at such high magnifications, Tamron’s 200- to 500-mm f 5-6.3 Di LD zoom is really quite decent optically, with a very good price-performance balance. It’s not optically stabilized, though, so a tripod is mandatory for sharp images (86-mm filter, 63 oz, $900).
- Sigma’s new 100- to 300-mm zoom has a constant f 4 aperture and it’s optically very good to excellent across the entire zoom and aperture range. One of the best zoom lenses in this magnification range, the Sigma 100- to 300-mm, is highly recommended by professional lens reviewers. It works well with Sigma 1.4x teleconverter (remember those?). (82-mm filters, 52oz, $1,100.)
- In direct competition with Tamron’s basic budget zoom is a comparable 70- to 300-mm f 4-5.6 zoom from Sigma (58-mm filter, 19 oz., $155). Tamron’s is about the same price, slightly lighter and sharper. I’d buy the Tamron.
- Tamron also bests Sigma among the image-stabilized VC 70- to 300-mm lenses. Sigma’s 70- to 300-mm lens ($360) has some construction issues, evident in the wobbling of the inner lens barrel as it extends when zooming. Tamron’s 70- to 300-mm VC version is also noticeably sharper, although about $70 more expensive. This is an instance where it’s worth paying a little more.
- Sigma’s 50- to 150-mm f 2.8 zoom is highly regarded and has very good, but not excellent, sharpness across its zoom range. This is intended as a pro-grade lens (77-mm filter, 28 oz, $700). Tokina’s 50- to 135-mm f 2.8 zoom is the closest competition. The Tokina is sharper but hard to find new.
- Sigma’s 70- to 200-mm f 2.8 zoom is another pro-grade lens (77-mm filter, 48 oz, $700). It’s quite sharp and optically very good, on par with Canon’s 70- to 200-mm f 2.8L and Nikon’s 80- to 200-mm f 2.8 pro-grade lenses.
- More or less unique is Sigma’s 120- to 300-mm f 2.8 lens, a very long telephoto zoom with a very bright, constant f 2.8 maximum aperture. This behemoth is particularly suitable for professional wildlife and film photographers who need very good optical quality at high-magnification, long focal lengths. Although very expensive in absolute terms, it’s well-constructed and a relative bargain compared to other wide-aperture, long-telephoto lenses (105-mm filter, 103 oz, $3,200). Use this one with a tripod or a monopod for extra support, even though the built-in autofocus and image stabilization are quite effective.
- Sigma makes a 150- to 500-mm supertelephoto zoom comparable to Tamron’s 200- to 500-mm zoom. Sigma’s sells for about $150, with a usual retail price in the $1,050 range. I would prefer the Tamron — it’s lighter and seems somewhat sharper.
- The fairly recent Sigma 120- to 400-mm f 4-5.6 zoom (62 oz, very large, $1,000) has decent optical quality across much of its range but the higher magnification settings tend to be soft. You’re likely better off with Sigma’s excellent 100- to 300-mm f 4 zoom lens and a Sigma 1.4x teleconverter.
Next week, we’ll wrap up our optical odyssey with a look at telephoto zooms made by Canon, Nikon, Pentax, Sony and Olympus.
Local attorney Joe Kashi received his bachelor’s and master’s degrees from MIT and his law degree from Georgetown University. He has published many articles about computer technology, law practice and digital photography in national media since 1990. Many of his technology and photography articles can be accessed through his website, http://www.kashilaw.com.