Since we spend 5 months a year in Florida, I often see bird photographers using huge 500-mm or 600-mm f/4 telephotos that cost $10,000 to $15,000. I cannot afford one of those, but my 70-300 mm lens is too short for frame-filling shots of egrets and spoonbills with my DSLR camera. Would a long telephoto zoom lens be just as good? This type is a lot more affordable, but what are the drawbacks?
Some of the mega-dollar super telephoto lenses that we have both seen in Florida are probably rented, Terry, and that is a suitable solution for occasional, short-term use, as discussed in the earlier Q&A “Can you recommend lens-rental companies in Canada?” (When renting while you’re in the U.S., however, contact an U.S.-based company that ships to where you will be, such as BorrowLenses.com or LensRentals.com.)
Of course, some telephoto zooms are also moderately to very expensive, including the Canon EF 100-400 mm f/4.5-5.6L IS II USM ($2400), Sony 70-400 mm f/4-5.6G SSM II ($2350), Nikon’s AF-S 80-400 mm f/4.5-5.6G ED VR ($3150), and the Nikon AF-S 200-400 mm f/4G ED VR II ($7900). Fortunately, photo enthusiasts can also find some models under $2000. These include the earlier L IS USM version of the Canon lens ($1780), the brand new Nikon AF-S DX 200-500 mm f/5.6E ED VR (for cameras with a DX sensor, $1650), and Tamron’s 150-600 mm f/5-6.3 DI VC ($1300).
Sigma offers three affordable zooms (available in all popular camera mounts) that are useful for sports or wildlife photography, including the 150-500 mm f/5-6.3 APO DG OS HSM and 50-500 mm f/4-6.3 APO DG OS HSM ($1700). Their latest 150-600 mm f/5-6.3 DG OS HSM C ($1300) model extends to a longer focal length. There’s also a premium-grade S version of the latter lens, with superior optics and construction, but that one ($2500) falls into in the moderately expensive category.
As you might expect, a $10,000 prime lens will produce better image quality than a zoom costing a small fraction of that price. However, unless you frequently plan to order 24 x 36-inch or larger prints from your photos, I’ll bet you would be satisfied by the better zooms in the sub-$2000 category. All feature some low-dispersion optical elements for good to very good image quality. For example, the Sigma 150-600 mm C lens features an FLD and three SLD elements, while the new Nikon 200-500 mm model includes three pieces of ED glass. Since the optical technology is only one aspect of probable image quality, it’s worth reading test reports of lenses you’re considering; you can find many reviews by searching online.
Of course, the maximum apertures of the affordable tele-zooms are smaller than those of the 500-mm and 600-mm f/4 telephotos that are common at the Rookery in Venice, at Merritt Island and at “Ding” Darling National Wildlife Refuge in Florida. Note that f/6.3 is typical at longer focal lengths, although a few do offer a slightly wider f/5.6. Autofocus will continue to operate even at f/6.3, as discussed in my previous Q&A about this small maximum aperture, but continuous tracking focus speed/reliability may be less impressive. This aspect is of greatest concern if you frequently photograph erratic birds in flight; check out the AF performance evaluations in the reviews.
Naturally, you’ll also need to use a higher ISO level to get fast shutter speeds with a zoom lens without a wide maximum aperture. On bright days, however, ISO 400 or 640 should allow for a shutter speed of 1/1000 s, for example, to “freeze” a moving bird. On overcast days, you might need to set ISO 800 or 1000, but current cameras produce excellent results at that level. All of the lenses discussed are equipped with an image stabilizer, helping to reduce the risk of camera shake when shooting handheld. And, because they’re more compact than the f/4 prime lenses, the zooms are more suitable for handheld use, a definite advantage in terms of portability, convenience and shooting versatility.