Friday, August 8, 2014

Fujifilm XF 18-135mm f3.5-5.6 Fujinon lens test (PART 1)

About two weeks ago, Fujifilm Middle East, was kind enough to borrow me a brand-new XF 18-135mm f3.5-5.6 Fujinon lens; Fuji's first weather sealed lens. As this will be a 2 part review, make sure you check out the second part through the link at the bottom of the page or by clicking here.

Since my copy had an "Editor sample" label on the box; I do not know whether the lens is 100% identical to the ones available in the stores today. Unlike the other XF lenses which are manufactured in Japan, the 18-135 has a Made in China label.



Marginally larger than the 10-24mm f4 lens and significantly smaller than the 55-200, the new zoom lens is not exactly a small lens. It does however balance very well on the X-T1 with either the larger MGH-XT grip or the vertical battery grip (VG-XT1). I lined up some of my XF Fujinon lenses, left to right; 14mm, 18-55, 10-24, 18-135 and the 55-200 for a size comparison.



The built quality is very good; pretty much as expected for a XF Fujifilm lens. As this is the first weather resistant lens, I was curious to see whether there would be significant change while operating the lens. Surprisingly, the focus and zoom-ring felt considerably softer than on the non-weather resistant lenses such as the XF 55-200. No an issue but with all the internal weather seals, I was expecting it to be the opposite...

Focus speed feels exactly the same as the 18-55mm and since I used the X-T1 focus tracking was good as well. I've always felt (not academic) that the 55-200 lens focusses slightly slower than most other XF Fujinon lenses and this has again been confirmed.

IMAGE SHARPNESS
For those of you that have read some of my previous lens reviews such as the Fuji is going WIDE with the 10-24 f4, you probably know that I'm not into doing typical lens sharpness tests etc... However because I was curious how the 18-135 would compare with the 18-55 "kit-lens" and the 55-200, I did shoot all three lenses at different apertures and focal lengths using a tripod and remote release, with the OIS in the OFF position.

Before going any further, I need to highlight that my copy of the 18-135, was considerably under-reading when setting specific focal lengths in the middle of the range; e.g. 35mm turned out to be around 32mm, 55mm being 49mm and 100mm being 93mm. The extremes 18mm and 135mm did show up as being correct. As I rarely set a specific focal length on the lens barrel, this is not a big issue for me, but one that I did not find on any of my other Fujifilm XF lenses. I'm wondering if this is a result of the lens being manufactured in China rather than Japan...

Illustrating with some 100% Lightroom screenshots (click on the image for a full  size view) below, I came to the following conclusions; 

Under the same conditions (f5.6, 35mm) the 18-135 is considerably softer at the edges with slightly less contrast than the 18-55 kit-lens. 

The same is true for a 55mm focal length on both the 18-55 and the 55-200, with the 18-135 always being the one on the left.


The 55-200 still wins the 100mm corner sharpness test,

Surprisingly at 135mm, the 18-135 is the winner over the 55-200! I even re-shot the sequence to double check and found again the same...

With the 18-135 lens not exactly being a fast lens (f3.5-5.6), its sharpness sweet-spot seems to be somewhere between f8 and f11; illustrated in the comparison shot below.


OPTICAL IMAGE STABILISER
Even though, Fujfilm does not have an in-camera image stabiliser, their optical image stabiliser (OIS), which is installed in most of their lenses, is top-noth! With the 18-135mm, Fujifilm takes it even a step further with up to 5 stops of image Vibration Reduction; sorry for using the old VR Nikon language!

As an illustration, the image below was shot handheld with a 55mm (82mm full frame equivalent) focal length, at a 1/3s shutter speed. Using the 1 over the full frame equivalent focal length rule of thumb, the "normal" handheld minimum shutter speed would be around 1/80s; so very close to the promised 5 stops! In order to make sure that it wasn't just pure luck, I shot a series of images, and had about a 90% success rate. 

The focus point on the image below was on the 0C mark, so the somewhat softer top and bottom are only a function of the limited depth of field.


FILTER SIZES
Unfortunately the lens has yet again a new diameter; with 67mm the lens barrel is smaller than the 72mm of the 10-24 and larger than the 62mm of the 55-200. One has to either invest in more filter sizes or use a step-down ring. For the ones using polariser and graduated neutral density filters, the good news is that the lens barrel does however not rotate while focusing, as it is done internally.

Enough of all the technical talk... In PART 2 of the lens review, we will have a look at some real life images shot with the 18-135 and we will try to find out who this lens is really for...


BJORN


  

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