Sometimes, size really does matter

If you want to photograph birds, you need as much focal length as possible. This image was taken with a 600mm lens.

Wildlife photography is probably my favorite activity. Of all the wildlife subjects, birds are by far the most challenging subject to photograph. They are fast, small, and extremely wary of humans. In this case, having the right gear really does matter. If you’re going to be a bird photographer, you not only need as much focal length as possible, but you also need a camera with fast autofocus, a solid tripod, and good technique.

Focal length: you can never have too much

I happen to own the Nikkor 600mm f/4 AFS G VR II lens. It’s a beast. It’s heavy, awkward to use, and requires its own special support system, not to mention ridiculously expensive. And despite its massive appearance, it doesn’t always get me as close as I’d like! Since we’re talking about bird photography, let’s consider this example. Most people, when they see my 600mm lens, assume I can get a frame-filling shot of a sparrow’s eyeball from 1000 meters. Not so.

Mickey Mouse photographed with a 600mm lens from 25 feet away.

I took Mickey Mouse out to the back yard to do some test shots with my 600mm f/4 and Nikon D3s (a full-frame DSLR). This particular stuffed toy is about 6″ tall, similar to most passerine birds. I placed Mickey on my fence and then set up my tripod 25′ (7.62m) away. In most situations, 25′ is about as close as you’ll get to a bird before it sees you and decides to flee. At this distance, I have a pretty good shot of Mickey; he fills about 1/5 of the frame. My point here, however, is that this often represents the best case scenario for birding. A warbler would be half the size of Mickey, and many times getting to within 25′ just isn’t possible!

What about teleconverters?

Nikon TC-14EII teleconverter

A teleconverter, sometimes called a tele-extender, is another lens that fits between your camera and primary lens. If you think you can slap a 2x converter on your 70-300mm zoom, you’re going to be disappointed. In my experience, teleconverters are only as good as the lens you use them on. A low-end consumer zoom does not have the optical quality to deliver a crisp image with a teleconverter. Second, teleconverters introduce a loss of light. A 1.4x TC will cost you 1 full stop of light, and a 2x TC will cost you two stops. That, in turn creates more problems. First, autofocus might not work if your effective aperture is smaller than f/5.6. If it does work, it’s likely to be less accurate and operate more slowly (not good with birding). In order to maintain reasonable AF performance with a 2X TC, your primary lens would need to be f/2.8 or faster. A budget lens like the 70-300 f/4.5-5.6 zoom Nikkor would have an effective aperture of f/11 with a 2x TC. To this end, Nikon’s own teleconverters are designed to be physically incompatible with many of their budget lenses. You might get a third-party TC to mount, but you risk damaging your lens because often the TC lens element will protrude into the lens slightly. On many zoom lenses, the rear lens element could come in contact with a TC. In conclusion, you’re back to square one. If you want good results with a TC, you need to put it on a fast telephoto lens, and that’s not a cost-saving option.

Mickey Mouse, photographed with a 600mm lens plus 1.4x teleconverter from 25' away (800mm equivalent focal length).

Crop-sensor DSLRs

One way to get extra “reach” with a telephoto lens is to use a crop-sensor DSLR. In the Nikon lineup, these are the “DX” bodies, such as the D7000 or D300s. With Canon, these are the “APS-C” sensors, like the one found on the EOS 60D. These cameras use a sensor that is smaller than traditional 35mm film (24x36mm), and the result is a narrower angle of view, sometimes called “crop factor.” An APS-C/DX camera will have a “crop factor” of around 1.5 or 1.6x as compared to a 35mm film camera. What this means is that your 400mm lens, when used on a DX body, will have a comparable angle of view to a 600mm lens used on a 35mm body. This is not to say that you’d produce identical images with a 400mm lens on a D300s and a 600mm lens on a D3s. The two lenses have different optical properties, different depth of field, etc. The only thing comparable would be the angle of view. Either way, using a DX or APS-C body is a great option for bird photography because more of the subject will fill the frame. If you choose a crop-sensor body, make sure that you get one with a good autofocus system and fast frame advance rate.

Other considerations when using long focal lengths

No matter how you achieve your effective focal length (teleconverter, crop-sensor body), keep in mind that minute vibrations are magnified tremendously. To get sharp shots, you’ll want to use a sturdy tripod, even if your camera/lens combination isn’t physically as large as a true 600mm lens. I normally use a Gitzo 3541LS tripod, but with my 600mm lens, I use the larger Gitzo 5541LS with a Wimberley head. The Wimberley head is a gimbal head that lets you balance the lens for nearly effortless tracking. With lighter lenses, a good ball-head, like the Really Right Stuff BH-55 can work well, especially when paired with the svelte Wimberley Sidekick, which converts a ball-head into a gimbal head.

If your lens has a stabilization system (Nikon VR or Canon IS), see if it has a “tripod mode,” which helps prevent unwanted stabilization artifacts. Older lenses, like the Nikon 80-400mm VR AF D, have problems when using the stabilization system with a tripod, so it should be turned off. Check your lens’ owners guide to see what the best settings are.

Keep in mind that image stabilization is only one component of a sharp image. Birds are fast; so you’ll want to use the highest possible shutter speeds for your shooting conditions (yet another reason why fast glass helps). I’ll often use manual exposure mode with auto ISO adjustment on my D3s. This setting allows me to choose both my shutter speed and aperture, and the camera will vary the ISO sensitivity settings to achieve the proper exposure. With newer DSLRs, high-ISO performance has gotten so good that I have no reservations about shooting at ISO 1600 or greater.

Location, location, location

The last bit of advice for great bird photos is to go to a place where you can get close, the birds are large, or both. One reason I love shooting in Florida is because many of the birds are quite large (herons and egrets) and are relatively accustomed to people, especially in the wildlife preserves. Another option is to use a blind, or hide, positioned near a bird congregation area. This technique will let you use shorter focal lengths because many times the birds will be very close. My image of the crested caracara in my eBook, Field Notes, was captured in Texas from a blind.

The author in Florida with the 600mm f/4 AFS G VR Nikkor (photo courtesy of Kristin Bishop)

Join me for a 5-day birding photo safari to the Florida Space Coast, January 29- Feb 2nd, 2012.

One thought on “Sometimes, size really does matter”

  1. Florida Space Coast
    sound good to be with Nikon 600mm but too far away from Mauritius.
    Wish you all the best. Good Luck

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