A teleconverter is an optical device that attaches to your telephoto lens to increase it’s magnification. It sits between the camera body and your lens to magnify the resulting image by 1.4X, 1.7X or 2X.

If the idea of using a teleconverter for bird photography has ever crossed your mind, you may be wondering what the catch is. After all, if you are able to increase the reach of your current lens by 1.4X or even 2X, why would you spend thousands to upgrade to a new lens with a longer focal length?

This is the exact question we had when we began looking into teleconverters for our Canon lenses. Until we are able to afford a big 500mm F/4 lens, we’ll continue to make the most of our modest 300mm and 400mm telephoto lenses. We currently use and enjoy the 1.4X Canon extender for our bird photography adventures.

A teleconverter has been a fantastic way to get closer to countless species of birds for some incredible shots using our Canon EF 300mm F/4L Lens. Small birds such as warblers need long focal lengths to properly capture feather details. Losing one stop of aperture is nothing compared to the advantage of the extra reach we gained.

Trevor always shoots with a 1.4X teleconverter attached to his 300mm lens

Should You Use a Teleconverter For Bird Photography?

While the idea of adding extra focal length to your existing telephoto lens may sound like a no brainer, there are some things to consider before making this upgrade to your kit. After spending several years with a Canon EF 1.4X teleconverter (extender) attached to our Canon EOS 7D camera, we’ve learned a few things about this configuration.

Here are some things to consider before purchasing a teleconverter for your existing camera lens if you’re into bird photography.

The teleconverter we use with our 300mm lens is the Canon Extender EF 1.4X II

Aperture and Loss of Light

Yes, it’s true that a teleconverter will affect the aperture of the lens you use it with. We use the Canon EF 1.4X teleconverter with our 300mm F/4L lens, which turns it into an F/5.6. Considering our best telephoto lens is currently a 400mm F/5.6L, it’s actually quite comparable. However, this reduced aperture can be off putting to those that really count on their autofocus and fast shutter speeds in low light situations.

“All teleconverters degrade image quality, though high end 1.4× TC’s (such as Canon’s 1.4× Extender II, which runs about US $380) when used with high-quality prime lenses typically produce very, very good image quality. ” – Digitalbirdphotography.com

1.7X and 2.0X teleconverters will lose even more light, up to 2 stops using the 2X version.

In the world of bird photography, fast lenses with wide apertures are critically important. Photographing species that hide in the shadowy tree canopies or only come out at dusk can be very difficult to photograph with lenses F/4 and above.

In full sunlight, however, a this is not a problem at all. As long as the lighting conditions are adequate, you can expect to get take sharp photos with a teleconverter attached to your lens. When using our Canon 1.4X teleconverter with a 300mm lens, we simply have to bump up the ISO in low light situations to capture a crisp shot.

If you’re not a fan of increasing ISO too high, and like to photograph species in low-light situations, a teleconverter may not be the best option. Our photography style is to generally shoot with sun behind us, to fully illuminate our subject and reveal its colorful plumage. In the photo below, a Black-throated blue warbler made a breif appearance into the sunlight. The Canon Extender EF 1.4X II worked flawlessly with our 300mm F/4 lens here:

 

In well-lit situations, a teleconverter can create brilliant, sharp images like the one above

What a Teleconverter Does to your Autofocus

The autofocus function of your camera works by detecting the subject and it’s movement, and it requires an adequate amount light to do it. So, if there is less less hitting passing through the lens, you may experience a delay in your autofocus function.

As you know, birds can move very quickly, and this requires an accurate autofocus system to keep up. Any amount of lag in these moments can be very frustrating, so this is something to be cautious about before deciding to use a teleconverter.

In our experience using the 300mm F/4 with a 1.4X teleconverter, the lag is very minimal, and is not preventing us capturing key moments. However, there have probably been many scenarios where a sharp photo of the bird at a greater distance would have been better than the ones captured at close range.

We’d recommend sticking to the 1.4X teleconverter if you are concerned about losing your autofocus function at a critical time.

Overall Weight is Much Lighter

A teleconverter and lens is much lighter than a large prime lens. If you enjoy using a smaller handheld lens rather than a tripod and gimbal system, a teleconverter may be a great option for you. They can easily be taken off (and even stacked) in the field, meaning you have the flexibility of changing focal lengths even if you’re using a prime lens.

There is a significant weight difference between a teleconverter and lens combination and a heavy prime telephoto of a comparable focal length. A large camera lens such as the Canon 500mm F/4L weighs a whopping 8.5 lbs, which can make using this lens handheld nearly impossible for some photographers.

Compare this to a 300mm F/4L + 1.4X teleconverter combination that is easy to use handheld for an entire day of shooting (less than 2 lbs). The difference of focal length is 80mm, yet the big 500mm prime is almost 7 lbs heavier! Of course the a prime lens with a native focal length of 500mm and an aperture of F/4 will outperform the smaller combo, but at the cost of some serious mobility.

List of Available Teleconverters and Extenders

Although I have only used the Canon ED 1.4X II extender myself, I did some research on the teleconverters available for Canon, Nikon, and Sony DSLR cameras.

Canon

• Canon EF 1.4X III Telephoto Extender for Canon Super Telephoto Lenses
• Canon EF 2.0X III Telephoto Extender for Canon Super Telephoto Lenses

Nikon

• Nikon AF-S FX TC-14E III (1.4x) Teleconverter Lens with Auto Focus
• Nikon Auto Focus-S FX TC-20E III Teleconverter Lens with Auto Focus
• Nikon AF-S FX TC-17E II (1.7x) Teleconverter Lens with Auto Focus
• Nikon TC-E3ED 3X Teleconverter Lens for Nikon

Sony

• Sony FE 1.4x Teleconverter
• Sony FE 2.0x Teleconverter

Sigma

• Sigma 2.0x Teleconverter TC-2001 for Canon
• Sigma APO Teleconverter 2x EX DG for Nikon Mount Lenses

Kenko

• Kenko 1.4X PRO 300 Teleconverter DGX Nikon AF Digital SLRs
• Kenko 2.0X PRO 300 Teleconverter DGX for Canon EOS Digital SLRs
• Kenko 2.0X PRO 300 Teleconverter DGX for NIKON AF Digital SLRs

Viltrox

• Viltrox C-AF 2x Magnification Teleconverter Extender Auto Focus

Vivitar

• Vivitar Auto Focus Teleconverter Lens for Nikon – Black (2X4N)

Fotodix

• Fotodiox Pro Autofocus 2x Teleconverter – AF Doubler x2.0 for Canon EOS EF, EF-S

The Bottom Line

As you probably expected, there are advantages and disadvantages of using a teleconverter for bird photography. For us, it has been a valuable upgrade to our bird photography gear that allows us to get much closer to our subjects. The loss of light, 1 stop of aperture and autofocus lag issues are minimal with our 300mm F/4L lens.

We do notice a slight increase in chromatic aberration with the 1.4X teleconverter in use with the 300mm F/4L lens. It’s only an issue when shooting at the brightest times of the day (noon), and when pointing the lens into the sun. The highlights of the bird (and especially the branches in the background) will show purple color fringing on the edges. This can quickly be corrected in Photoshop using the “defringe” option in the “lens correction” tab of Adobe Camera Raw.

If this is not something you’re willing to perform in post-processing periodically, you may want to start saving for that giant prime lens you’ve been eyeing. For us, it’s a simple part of our image processing workflow.

A 1.4X teleconverter is a safe bet if you are looker to extend your focal length with a lens in the F/4 range. You’ll increase your reach to 420mm, and continue to enjoy the benefits of mobility and the cost savings from a combination like this. The advantages far outweigh the drawbacks of this option, but be sure to invest in a quality teleconverter that’s a good match for your lens.