I’ve been using the Nikon TC-14E teleconverter now for years. Even though it was “updated” to the MkII model a while ago, the only differences between the TC-14E and TC-14EII were the exterior cosmetics (finish). The optical formula remained the same (5 elements in 5 groups) between them.
Recently, Nikon completely redesigned their 1.4x teleconverter, and released the TC-14EIII. This new teleconverter uses a different optical formula (7 elements in 4 groups) and includes fluorine-coated front and rear elements to improve resistance to dirt and oil. The body of the TC-14EIII was also redesigned, to include a more prominent grip. It also includes weather-sealing (gasket) on the F-mount.
The real question is whether the new TC-14EIII is better optically than its predecessor. While all teleconverters will degrade an image, the 1.4x versions are usually the least destructive. The TC-14E/EII has long been considered to be an excellent teleconverter, delivering sharp results across a wide range of Nikon telephoto lenses.
Before I go on, let me remind you of a couple key points about teleconverters.
- Teleconverters restrict light coming into your lens. A 1.4x TC results in a one-stop loss of light. Thus a f/4 lens becomes a f/5.6 lens when shot wide-open using the converter.
- Teleconverters magnify imperfections in your lenses. If you put a teleconverter on marginal glass, you’ll notice soft corners and other imperfections that you may not have seen. The better your base optics, the better results you’ll get when using a TC.
- Nikon teleconverters (TC-14E, TC-17E, and TC-20E models) only mount on certain AF-S lenses. The F-mount is modified to work only with a specified list of telephoto lenses. You cannot physically connect a Nikon TC to lenses it is not compatible with.
- On lenses with maximum apertures of f/5.6 or greater, autofocus may not operate well or at all unless you are using a newer Nikon DSLR, such as the D4, D800, D810 or D750.
In order to compare the TC-14E with the TC-14EIII, I set up my Nikon D810 on a tripod. I used mirror lock-up to eliminate camera shake. For each converter, I focused using Live View and then set the camera to manual focus to lock the lens focus. My test target was a newspaper taped to my wall about 8′ from the camera.
I tested each teleconverter on my Nikon 70-200mm f/4 AFS G VRII lens. I know from experience that this is an incredibly sharp lens that handles teleconverters well. I examined the teleconverters performance from f/5.6 (wide-open) to f/11. My rationale being that most of the time you’ll be wanting to use your lens as close to wide-open as possible to maximize shutter speed.
Once I captured the images, I viewed them side by-side in Lightroom 5 with all lens corrections disabled. I wanted to see any effects of vignetting or distortion on the images. I compared the center and corners of each aperture pair.
Overall, both the TC-14E and TC-14EIII were excellent in the center of the image frame across the range of tested apertures. As I moved to the outer third of the frame, The images from the TC-14EIII had slightly better contrast and sharpness. In the extreme corners, the TC-14EIII images were sharper than those using the TC-14E.
I also noticed that despite identical exposure settings, the images from the TC-14EIII were between 1/6 and 1/3EV brighter than those captured using the older TC-14E. This may be due to slight differences in optical coatings. Nevertheless, the histograms clearly indicated that the shots captured with the TC-14E were slightly underexposed as compared to the new teleconverter. Both converters handled light fall-off well.
At f/8 and f/11, both teleconverters delivered excellent results, with the TC-14EIII having a very slight advantage in the image corners.
For each of the images below, click to see a larger view.
The TC-14EIII is Nikon’s latest redesign of their venerable 1.4x teleconverter. Optically, the new design delivers slightly brighter and sharper image corners than the previous version. For photographers looking to maximize image quality on pro glass, the TC-14EIII is an excellent teleconverter. It also adds weather-sealing and dirt/oil resistant coatings, making it desirable for outdoor/nature photographers.
Overall, the optical differences between the new and old teleconverter designs were quite subtle. Unless you’re using top glass, such as Nikon’s telephoto primes, and a high-resolution camera like the D810, you probably won’t notice too many differences in everyday images. In fact, if your images are close-ups with out of focus backgrounds, then the improved corner sharpness won’t have any bearing on your photos whatsoever.
The Nikon TC-14EIII teleconverter lists for just around $500. The TC-14EII has been discontinued, but can be found on the used market.