Tuesday, January 5, 2016

The Fuji 1.4x teleconverter -- a Hands-on review

The Fujifilm XF 1.4x TC WR teleconverter is intended to fit two lens -- the current 50-140mm f/2.8 zoom, and the 100-400mm to be released later this year -- multiplying their focal length ranges by 1.4x with a loss of only one f/stop. This makes the 50-140mm a 70-196mm f/4, and the variable aperture 100-400mm f/4.5-5.6 lens a 140-560mm f/6.3-8 zoom, and means that the Fuji X mirrorless system now extends its optical system into the long telephoto range, albeit only with zooms.

Anytime you put a teleconverter on a lens, you are going to compromise the quality of the original optics. The real question is: How much lens quality are you going to sacrifice? The very best teleconverters are usually made by the lens manufacturer and are dedicated to a particular lens set in a way that minimizes the loss in quality. Many off brand converters, on the other hand, can be downright awful.

Because Fujifilm is known for its superb optics I went into this test thinking (and hoping) that the combination of the Fuji 50-140mm zoom plus 1.4x telextender would be capable of excellent results. I redid my tests four times, even changing cameras once, to be certain that the results I was seeing were true. They were.

The Fuji 1.4x teleconverter plus Fuji 50-140mm zoom lens mounted on an X-T1 camera makes for a hefty package. 

At wide open apertures the zoom/1.4x combo is showing corner softness, especially at the longer focal lengths.  I have included several downloadable test images below taken at various apertures so you can judge for yourself. Suffice it to say, for maximum sharpness over the full frame I would not advice anyone to shoot with a wide open aperture using this teleconverter. Stopping down at least one stop to f/5.6 or, preferably, two stops to f/8 will vastly improve the results in sharpness.

The adapter adds only a small amount to the overall length of the lens because much of its optics extend into the rear barrel of the zoom. 

The adapter adds only a slight 5/8" (1.5cm) extension to the lens. The telextender itself is much longer, but part of its optical system has been designed to fit inside the lens barrel of the zoom.

The 1.4x telextender adds only 5/8" to the overall length of the zoom. 

The normal auto-focus of the 50-140mm seems not to be affected with the addition of the telextender, however I did not try it on any moving subjects, such as fast moving animals. I expect that if you are satisfied with the performance of the 50-140mm zoom itself, you will also be satisfied with the AF performance of the added 1.4x telextender.

With the 1.4x attached the 50-140mm zoom now extends out to the range of Fuji's other telephoto zoom, the 55-200mm variable aperture f/3.5-4.8. I did a few test of one system against the other and the teleconverter plus 50-140mm did offer sharper performance, especially in center areas of the frame, than the 55-200mm zoom.

This image shows the lens plus telextender at full extension and f/5.6.   Download a high res version of this file by clicking here.

The lens is weather sealed with dust resistance, is comprised of 7 elements, and passes all information from the lens to the camera.

In this test the lens was set to the lower end of its zoom range at 70mm with the 1.4x for an equivalent of 105mm. Here, even with a wide open aperture of f/4, the performance was much improved over the longer focal lengths. Download a high res version of this file by clicking here. 

This test sequence provides a sample of the center sharpness of the lens plus telextender combo at three apertures.
Download a high res f/4 version of this file by clicking here.
Download a high res f/5.6 version of this file by clicking here.
Download a high res f/8 version of this file by clicking here.

This image demonstrates the selective focus ability of the lens and teleconverter when used wide open and in close.

Download a high res version of this file by clicking here.

Download a high res version of this file by clicking here.

This portrait, taken at the maximum zoom length of 294mm (equivalent) at f/4 shows the selective focus of the 1.4x plus zoom. 

Download a high res version of this file by clicking here.

The XF 1.4x teleconverter added to the 50-140mm zoom does not add excessively to the length of the lens. 


I am used to lavishing superlatives on the Fuji lenses. In general, they represent some of the best camera optics out there. The Fuji 1.4x telextender adds a much welcomed, pro-level, fast-aperture zoom to the lens lineup. It would have been nice if the telextender could be used on more than two lenses, but it is better to have had it designed specifically for overall performance than for simply for convenience.

Telextenders are a tough breed of optics to design correctly. I have used them -- both good and bad -- for many years, notably on the Nikon system cameras, and can appreciate the quality and effort needed to produce a top notch optical combo of telextender, fast aperture, and still preserve lens quality and AF speed. Fuji has done and excellent job of filling the bill with the XF 1.4x telextender. By extending the focal length range it will definitely make the 50-140mm f/2.8 zoom a more practical lens to carry around.

If you are planning on buying this camera or lens, you can help support this site at no extra cost to you by clicking the link and purchasing from one of our affiliate sellers listed below -- and thanks for your support.

The Fujifilm XF1.4x TC WR teleconverter can be ordered for $449 from:
  BH-Photo    Amazon   Adorama

Download a high res version of this file by clicking here.

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