I’m excited about a new bird photography lens I have for my DSLR- Sigma’s 50-500mm f/4.5-6.3 offering. (Yeah, you read right- 50-500mm!) This is an optically stabilized, APO glass lens with a very fast autofocus system. Sigma produces versions of the lens for Nikon, Canon, Sony, Minolta, Pentax, and Sigma camera mounts.
Crested Caracara near Brownsville, Texas, March 2011. © Bill Schmoker
Two recent events turned me on to this lens. First, I was birding with my friend Steve Mlodinow who was sporting a remarkably compact DSLR rig and getting great images. I was pretty floored when he told me about the jaw-dropping 10X range of the zoom, and that it topped out at 500mm (~750mm equivalent on most DSLR bodies.) While far from small, the lens was substantially shorter (with zoom fully retracted) and lighter than my big Nikon 200-400mm f/4. Crazily, he could get serviceable digiscoped images through his Kowa scope with the lens pulled all the way back to 50mm or reach out at full 500mm zoom for more traditional telephoto work all with the same lens!
The second impetus to look seriously at getting the lens was an upcoming bird photography tour in the Lower Rio Grande Valley of Texas which had me trying to sort out how I’d fly down with both DSLR rig and scope in my trusty WRP MP-1 camera bag (a carry-on that fits every overhead compartment I’ve yet tried- even those in little twin turboprop planes.) Ordinarily, on birding trips involving flights I pack my big DSLR glass and use a friend’s scope (or go scopeless), but as trip leader I was obligated to have a scope along. The Sigma 50-500mm (hereafter “Bigma“) easily shared the photo pack with my D300 camera body, spotting scope, bins, flash, and other accoutrements. All photos in this post are from my recent LRGV trip taken with the Bigma on a Nikon D300 body.
Now don’t get me wrong- I love my Nikon 200-400 f/4 and have no immediate plans to give it up. But it is a mighty piece of ballast to carry around, at about 7.4 lbs. and nearly 15″ long (sans hood.) In contrast, the Bigma tips the scales at 4.3 lbs. and collapses down to a scant 8.6″ long. In addition to bulk & weight, big telephotos by both Nikon & Canon (f/4 or f/2.8) all share another painful trait- prices in the high thousands (ouch!) While not cheap, the ~$1650 price tag on the Bigma is certainly a lot more palatable.
I’ve been a fan of modern high-end zoom telephotos ever since I got a Nikon 80-400mm f/4.5-5.6 and later upgraded to my Nikon 200-400mm f/4, enjoying their versatility without the need for frequent lens switching. The Bigma takes this to a new extreme, letting me pull all the way back to 50mm (75mm equivalent on most DSLR bodies) for scenics, people pics, or flock shots. While most of the time I want maximum magnification for bird photography, there are times where an intermediate telephoto setting is also very nice to have at hand, such as with close birds and for difficult flight shots. I found the Bigma to perform quite well across its zoom range, yielding sharp images so long as I payed attention to good hand-holding technique & maintained adequate shutter speed.
One change I had to make when using this lens was to bump my ISO up a notch or two above what I’d usually use with my Nikon 200-400 f/4 (or f/5.6 when used with a 1.4X teleconverter as I usually do.) The Bigma yields f/6.3 at full zoom and so I’d often go to ISO 500, 640, or 800 depending on the degree of sunlight or shade to keep shutter speeds up. I was very pleased with the focus speed, finding that the lens did a nice job on flight shots and pulling little birds out of brushy & branchy settings. The only trouble I had was picking out little targets when it was extremely dark, like in a combination of heavy forest on cloudy days. I found myself wishing for a focus range limiter switch as well- something my Nikon 200-400 sports. This is nice for things like flying birds, significantly cutting down on the focus cycle time as the lens “searches” for its target. A nice touch is the Bigma’s zoom lock, which keeps the lens tube from expanding as you carry it around. I just wouldn’t want to forget to switch it off when trying to zoom in on a bird!
I found that the Bigma was reasonably comfortable to carry around all day, even with a scope rig on my other shoulder. Maybe it’s just that I’m just getting older but I rarely try to pull off a scope/DSLR carrying combo for long sessions using my bulky Nikon 200-400. The Bigma’s lighter weight also makes it easier to swing onto & track flying birds while hand-holding the lens compared to my bigger glass. The image stabilization (OS in Sigma parlance) worked well, allowing hand-holding down to pretty slow shutter speeds provided the bird also cooperated by standing still.
In optics, the saying that you get what you pay for generally rings true. If you are after a magazine cover or routinely make large prints then sticking with a tripod-mounted f/4 or f/2.8 telephoto is probably the best bet. But for traveling &/or photographing birds on an opportunistic basis as you are birding I think the Bigma is a fantastic option to have. Nikon & Canon have similar offerings (their 80-400mm & 100-400mm zoom telephotos), but I think that the Sigma 50-500mm will give those a serious run for the money with its longer reach and astounding 10X zoom range.