- Usually faster
- Usually sharper
- Less expensive
- Less expensive than another lens
- Minimum lens focusing distance is retained (good for macro)
- Much lighter than a longer lens
- Slight to moderate loss in image sharpness
- Light reduction causes loss of 1 to 2 exposure stops
- Aberrations are multiplied (fringing, flare, distortion, etc.)
- One extender does not work with all lens brands and types
- Some or all lens functionality may be lost, such as AF
Although the camera you use for bird photography is important, almost any serious photographer will tell you that it's the glass that makes the real difference. Besides the obvious fact that focal length is a factor, there are some other unique challenges in photographing birds in the wild. Poor lighting conditions, movement and other issues can often be too much for the average kit lens to produce the best quality in your bird images. This lesson will address some of the features you'll want to consider when selecting a lens for bird photography and some of the options to consider.
Let's start with the obvious. When it comes to birding lenses, size matters. For most of us, the first thing that comes to mind when you think about lens size is focal length. Most bird photographers agree that 300mm is the minimum you'll want to use in the field. More often, you'll see the pros using 500mm or 600mm lenses. There's no need to go into lengthy explanations here; getting close is easier with a longer lens.
It's important to remember that in addition to the image, any movement is also magnified, so the longer your lens, the more prone to problems with camera shake you'll be. Sure, you may be able to see your subject better at 1200mm, but the slightest twitch is going to ruin your shot at that magnification.
If you've ever wondered whether lens diameter matters, too, the answer isn't quite so obvious. Those great, big objective lenses on pro-series telephoto lenses are often that large mostly because they had to be engineered that way to accommodate all the lens elements while minimizing aberrations and allowing the largest possible maximum aperture and projecting a large enough picture for the sensor.
Side effects of the diameter increase include better light gathering, better motion freezing and noise reduction, so in effect, yes, diameter matters. Of course, the larger diameter also means you're going to pay more for accessories for that lens, such as filters and hoods.
This is one of the most important considerations when selecting a lens for avian photography. For those few readers who aren't familiar with the term, lens speed refers to the size of the maximum aperture setting. That's because a wider aperture admits more light, allowing a faster shutter speed. Wider apertures also allow better use of selective focus.
Since aperture sizes are expressed in f-stops representing a reciprocal number, faster lenses will have smaller f-stops. In other words, a 300mm f/2.8 lens is MUCH faster than a 30mm f/5.6. It's also going to be MUCH more expensive. The formula here is simple: buy the fastest lens you can afford.
Image Stabilization, aka Vibration Reduction
For any telephoto birding lens, IS, or VR is an important feature to look for. Is it an absolute necessity? No, but it will make your life much easier. Stabilization systems in newer lenses have advanced to the point that it's possible to hand-hold telephoto lenses in some situations, with considerable practice. In bird photography, that means you maybe able to grab that quick shot even though you haven't yet set up your tripod. When selecting a lens,
Autofocus may be your best friend in bird photography. Compared to landscape photography, the opportunities to take your time in setting up a shot and focusing manually will be fewer and farther between. You're going to be busy keeping your subjects framed, and they're often going to be moving very fast. The autofocus motor of your lens needs to react quickly to the signals sent from your camera's sensors, especially when you're shooting birds in flight, with focus tracking set. A quiet motor is also an advantage, since many of your subjects will startle easily.
Zoom vs. Prime
Another choice to make when considering a lens or lenses for photographing birds is the choice between one or more prime lenses or a telephoto zoom lens. The advantages of each are very straightforward:
Of these points, the one that's usually most outstanding is the cost factor, however many pros will stick with one prime lens because of its sharpness. For the beginner, a single prime lens in the 300mm to 500mm range is often a good choice.
It doesn't take long to figure out that price tends to increase with focal length. For those of us with limited budgets, the option of using a teleconverter, also known as an “extender” is worth considering. Generally speaking, you can find good quality teleconverters that increase lens magnification from 1.4 to 2 times the focal length. At around $150 to $500, many photographers will choose this option to save a few thousands dollars or more on a more powerful lens.
Here's a short list of pros and cons for focal length extenders:
As you can see, the choice comes down to a compromise. Many professionals use extenders for bird photography with excellent results, because they make the necessary adjustments in the field and correct issues in post processing. Canon and Nikon make excellent teleconverters for their lenses and Sigma, for one, manufactures them in brand-specific models that receive good reviews from photographers.
One other option worth mentioning is the recent availability of high-end lenses for rent. If you have an opportunity for bird photography but lack the high-end equipment you'd like to use, you can now consider renting professional lenses from several sources. This is also a great way to field test different lenses, to find the one that best fits your needs and shooting style.
Lens choices for bird photography will depend greatly on your budget. The longest, highest quality lenses carry price tags of tens of thousands of dollars. Other alternatives may fall in the range of a few thousand dollars, and low-end, “kit” lenses will severely limit your success in this field. Try to use a lens with a focal length of 300mm or higher and the widest maximum aperture possible. Autofocus and stabilization will help you achieve better results. If your budget is tight, consider a prime lens with an optional teleconverter.
Whatever your lens choices, be prepared to spend a lot of hours practicing in this genre. Our upcoming lessons will help you get the most out of your investment in the shortest time. Our next lesson will deal with the other equipment you're going to want to consider having when you head out to shoot birds in the wild.