This is an in-depth review of the new Nikon TC-20E III teleconverter that was released in December of 2009, along with an updated version of the Nikon 300mm f/2.8G VR II lens. The Nikon TC-20E III is a major update to the existing Nikon TC-20E II teleconverter, sporting a brand new optical design with an aspherical element, which delivers better performance with many specialty telephoto lenses. The purpose of teleconverters is to increase the focal length of lenses, in other words to get closer to subjects, and the TC-20E III is the biggest and the longest teleconverter manufactured by Nikon – it doubles the focal length of a lens. While this teleconverter works with any professional Nikon lens that can take teleconverters, it is specifically designed to work with fast prime lenses with an aperture of f/2.8 and larger. The Nikon TC-20E III is targeted at sports, wildlife and other types of telephoto photography where the photographer cannot physically approach subjects.
It was not easy to obtain the Nikon TC-20E III because of high demand/short supply and after waiting for a few weeks, I decided to just rent it for a couple of weeks instead. My objective was to try the Nikon TC-20E III specifically with the Nikon 300mm f/2.8G VR II and with the Nikon 70-200mm f/2.8G VR II to see how it truly performs in an outdoor environment when photographing nature. It is one thing to shoot test charts with a lens sitting on a tripod, and another to get out and do some real shooting. Some lenses look great on paper and on test charts, but cannot perform equally well when used in an outdoor environment, especially with fast-moving subjects like birds. The primary reason is autofocus, the performance of which depends on many different factors. Teleconverters generally negatively impact autofocus performance, due to a considerable loss of light and contrast and the 2x TC is the worst in this regard. Adding a teleconverter slows down lenses and the Nikon TC-20E III slows down by two full stops. What this means, is that when the teleconverter is mounted on an f/2.8 lens, it slows down to f/5.6 and as you may know, autofocus performance on small apertures beyond f/5.6 is unreliable even in broad daylight conditions. Nikon clearly points out that autofocus does not work beyond f/5.6, so if you have an f/4.0 lens, forget about autofocus – you will have to resort to manual focus.
In addition, due to the considerable number of additional glass elements, the lens sharpness performance can suffer significantly, depending on the quality of the lens. While lenses like Nikon 200mm f/2G VR II, Nikon 300mm f/2.8G VR II and Nikon 400mm f/2.8G VR work great with 2x teleconverters, some lenses like the Nikon 70-200mm have been known to perform very poorly with any teleconverters longer than 1.4x. As I have demonstrated in this review, the new Nikon 70-200mm f/2.8G VR II works beautifully with the Nikon TC-20E III when stopped down a little, which was a nice surprise. Let’s take a closer look at the teleconverter.
1) Lens Specifications
- Enhanced telephoto versatility – affordable and portable gateway to extend telephoto reach; ideal for sports, wildlife, surveillance and more.
- Aspherical lens element virtually eliminates coma and other aberrations, especially at wide apertures.
- 2x optical conversion factor doubles the focal length of select compatible NIKKOR lenses.
- Nikon Integrated Coating (IC) enhances light transmission efficiency, improves color consistency and reduces flare.
- Mount Type: Nikon F-Bayonet
- Lens Elements: 7
- Lens Groups: 5
- Optical Conversion Factor: 2.0x
- Light Loss: 2 f-stops
- Compatible Format(s): FX, DX, FX in DX Crop Mode, 35mm Film
- Autofocus: Yes
- AF-S (Silent Wave Motor): Yes
- Dimensions (Approx.): 2.6×1.8 in. (Diameter x Length), 66x46mm (Diameter x Length)
- Weight (Approx.): 11.06 oz. (330g)
- Supplied Accessories: BF-3A front lens cap, LF-1 rear lens cap, Cl-0715 Lens Case
Detailed specifications for the lens, along with MTF charts and other useful data can be found in our lens database.
Nikon TC-20E III compatibility and performance chart:
|Lens Description||Effective Focal Length||Autofocus||Acceptable Sharpness||Optimal Sharpness|
|* Acceptable and optimal sharpness numbers above are estimates, based on various tests and feedback from users|
|AF-S Micro-NIKKOR 105mm f/2.8G IF-ED VR||210mm f/4.0||No||f/8.0||f/11.0|
|AF-S NIKKOR 200mm f/2G IF-ED VR||400mm f/4.0||Yes||f/4.0||f/5.6|
|AF-S NIKKOR 300mm f/2.8G ED VR II||600mm f/5.6||Yes||f/5.6||f/8.0|
|AF-S NIKKOR 300mm f/2.8G IF-ED VR||600mm f/5.6||Yes||f/5.6||f/8.0|
|AF-I NIKKOR 300mm f/2.8D IF-ED||600mm f/5.6||Yes||f/5.6||f/8.0|
|AF-S NIKKOR 300mm f/4D IF-ED||600mm f/8.0||No||f/11.0||f/11.0|
|AF-S NIKKOR 400mm f/2.8G ED VR||800mm f/5.6||Yes||f/5.6||f/8.0|
|AF-S NIKKOR 400mm f/2.8D IF-ED II||800mm f/5.6||Yes||f/5.6||f/8.0|
|AF-S NIKKOR 400mm f/2.8D IF-ED||800mm f/5.6||Yes||f/5.6||f/8.0|
|AF-I NIKKOR 400mm f/2.8D IF-ED||800mm f/5.6||Yes||f/5.6||f/8.0|
|AF-S NIKKOR 500mm f/4G ED VR||1000mm f/8.0||No||f/11.0||f/11.0|
|AF-S NIKKOR 500mm f/4D IF-ED II||1000mm f/8.0||No||f/11.0||f/11.0|
|AF-S NIKKOR 500mm f/4D IF-ED||1000mm f/8.0||No||f/11.0||f/11.0|
|AF-I NIKKOR 500mm f/4D IF-ED||1000mm f/8.0||No||f/11.0||f/11.0|
|AF-S NIKKOR 600mm f/4G ED VR||1200mm f/8.0||No||f/8.0||f/11.0|
|AF-S NIKKOR 600mm f/4D IF-ED II||1200mm f/8.0||No||f/8.0||f/11.0|
|AF-S NIKKOR 600mm f/4D IF-ED||1200mm f/8.0||No||f/8.0||f/11.0|
|AF-I NIKKOR 600mm f/4D IF-ED||1200mm f/8.0||No||f/8.0||f/11.0|
|AF-S NIKKOR 70-200mm f/2.8G IF-ED VR||140-400mm f/5.6||Yes||f/11.0||f/11.0|
|AF-S NIKKOR 70-200mm f/2.8G ED VR II||140-400mm f/5.6||Yes||f/5.6||f/8.0|
|AF-S NIKKOR 80-200mm f/2.8D IF-ED||160-400mm f/5.6||Yes||f/8.0||f/11.0|
|AF-S NIKKOR 200-400mm f/4G IF-ED VR||400-800mm f/8.0||No||f/11.0||f/11.0|
|AF-S NIKKOR 200-400mm f/4G ED VR II||400-800mm f/8.0||No||f/11.0||f/11.0|
The lenses with f/11 for both “Acceptable” and “Optimal” sharpness produce very unreliable results.