This week I have borrowed the XF 1.4X TC WR teleconverter for use with the 50-140 Zoom. (It also works with the newly announced 100-400 ).
I needed to find out how the lens with converter would work in “not ideal conditions” so I took an X-T1 with the lens and converter mounted out early on a dark stormy morning before the sun had fully risen. There are plenty of technical reviews, in perfect conditions, with nice blue skies, I need to know how it performs in the poor light and conditions I am likely to get. If it functions in these, it will function on a nice bright summers day.
So, these test images are all straight from the camera shot at either 6400 or 3200 iso, slow shutter speeds and mostly slightly underexposed. Not a case of getting pretty images but a case of “what can I get away with”. All the images are taken at “Full Zoom” i.e. 140mm (200mm).
Starting with our local pier.
This shows the difference in the reach of the lens with the converter against the lens alone.
At 1:1 these images look like:
Remember – straight off of camera JPG, only cropped here.
Testing the optical image stabilisation:
So yes! Thats 1/60th with an equivalent focal length of 300mm, The OIS seems to work fine! I was also testing the focusing at this point and the tracking did track the cyclist ok (ok, not that fast but I don’t do sport).
I could also track this flying bird ok although acquiring the subject was a little harder/slower so I would say the focusing is defiantly affected (it would be due to the light loss) but the effect is acceptable for my work. If you shoot sports I would check for yourself.
But that is not everything. There are issues:
Firstly, mounting the converter: The convertor is shaped it slides up within the barrel of the 50-140. I am sure this enables the high image quality to be delivered but it did mean I felt I needed to be far more careful mounting the converter on the lens. My routine was:
- Lens off of camera
- Converter onto lens
- Finally mounting the combination back on the camera body.
Far slower than a face-to-face mounting and meaning that the body is open with an exposed sensor for a longer time than I would like.
Secondly, reported focal lengths and aperture values: When using a converter on my Nikons. The camera (and EXIF data) would report the resultant aperture (i.e. F4 opposed to F2.8) and focal length (i.e. 200 opposed to 140). The X-T1 was not doing this (tested in Firmware 4.0 and 4.20), the EXIF information reported was for the lens alone. This is addressed by ensuring that not only the camera body is running the latest firmware but also the lens. It turns out that during my testing, my lens was not running the latest. I am assured the correct data is reported when all is updated.
So to sum up:
I am fairly sure the performance under conditions I would use it are fairly acceptable with slight degradation in focus performance and an imperceptible difference in image quality. I suppose one big question is “How does the performance compare with the 55-200”. My gut feeling is it out performs it but without measurable back-to-back testing thats difficult to say.
The big lesson of the day is:
Always ensure that both the lens and the body are updated to be running the very latest firmware as there may be issues that are not apparent whist using the kit that may affect the data further down the line.