Lens Test Glossary     About these reviews

I bought mine here

I bought mine here

Introduction

This is an expensive 2x teleconverter. It ONLY works with expensive AF-I and AF-S lenses. One CANNOT mount any other lenses on it unless one grinds down certain lugs on the female mount at a machine shop.

Nikon cheapened it a little (same glass) and introduced the TC-20E II around 2001. I have the more expensive original model.

Both models work with the AF-I and AF-S lenses.

Nikon makes NO AF teleconverters for its general line of AF lenses. One must instead use the manual focus TC-200 and focus manually, or screw with discount brands and hope the matrix metering couples correctly.

To retain AF ability with ordinary AF lenses one must slum it with a discount brand teleconverter.

Specifications

It has seven elements in six groups.

It's 2.6" (65mm) around by 2.2" (55mm) long.

It weighs 12 oz (340 g).

Nikon Product Number: 2130 (TC-20E II) , in catalog as of spring 2008.

Performance

I've used the TC-20E with the 400/2.8 AF-I and the 80-200/2.8 AF-S. See those reviews for details of performance with this converter.

Remember that the sharpness of a system with a TC is dependent more on the prime lens and chance than the TC itself. The TC is magnifying the image from the lens by 2x. A lens needs to have over twice as much sharpness as you need to begin with to look good with a 2x converter. The 400/2.8 doubles great. Remember that zooms have come a long way today, but when you double them you just may not have the excess performance you need to get what you want.

It works great with the 400/2.8 AF-I. AF is slower than the 400mm naked, but still fast and right on, and the whole system is still very sharp. I use this on a rickety monopod (as seen on my home page) with Velvia and get great results.

The results with the 80-200AFS are variable. Sometimes I'm happy, other times the results are so-so. AF speed is slower but still reasonable. Since I usually use this set up handheld I can't really get fast enough shutter speeds at f/5.6 in daylight with Velvia to get consistently sharp results with a 1/250 shutter speed at f/5.6 in full daylight at 400mm.

Recommendations

If you have an f/2.8 AF-S or AF-I super telephoto lens this is a very handy addition.

It is useless unless you have an AF-I or AF-S lens of f/2.8 or faster. One CANNOT mount any other AF or manual lens or accessory to the front because it is keyed mechanically to prevent this.

It makes little sense to use this with the 28-70AFS, and you'll damage the system if you set the 28-70 lens to its shorter focal lengths since glass will collide. Only silly people worry about the fact that this probably does not work with the 17-35AFS.

Just for fun, you can attach another manual focus teleconverter to the rear of this, but not the front.

This convertor is intended for professional use with long super telephotos. It is not like the old TC-201 teleconverter that was intended for general use to make a normal lens into a telephoto. Likewise, the results are great with 300mm and longer fixed AF-I and AF-S lenses and so-so with the 80-200 AF-S zoom.