How good is the X100F lens?

Reason wanted me to be smart, but I bought an X100F on the release day in 2017. Am I happy that I spent 1400 Euros, plus several hundred more for accessories? This is a camera with a fixed lens, which cannot even zoom.

Some things are not as good as hoped for. My main criticism is the autofocus miss ratio. The camera sometimes confirms the focus while in fact the whole frame is blurry. I rather check the focus before taking an important photo than accepting the small risk of spoiling it.

In many other regards, like the X100F. The camera looks fantastic and is easy to use and satisfying to operate. The highly configurable viewfinder is something did not expect from a compact camera.

What about the lens?

Perfect output versus having a soul

The lens has a couple of small issues, most of them are not relevant in the everyday routine. If those issues come into play, it is easy to work around most of them. But why always produce technically perfect, bloodless images? The optical properties of this lens can add something.

An X100 is prone to flare issues and internal light scattering, sometimes when the sun is not even in the frame. But there are cases where those issues result in atmospheric images. This example shows only some of the many possible artifacts. It is up to the photographer to avoid, or to employ them.

A distorted view

Every X100 image has some geometric distortion, which is not corrected in the camera. Architecture with straight lines can reveal these issues, especially close to the frame edge. As a solution, one can use third-party software. Lightroom 6.9 or higher for example comes with a lens profile for X100F raw image files. The profile is not available for X100F Jpegs, but a Jpeg seems to be corrected quite well with Lightroom’s “Sony DT18-200” profile. As alternative, the distortion slider can be set to +5, with “Constrain Crop” applied.

The distortion is so small that in most case I don’t correct it. It can even be helpful in order to compensate for perspective distortion near the border. That kind of perspective distortion would be mathematically correct, but is not flattering for people near the frame edge, as the person’s body and the head get bent a bit too much. The X100F lens provides a less accurate, but better looking image in this special case.

Point light rendering

As the X100F has no image stabilization, it can be difficult to use it at night. But in a city it is possible to get acceptable results operating the camera hand-held. Depending on the aperture, point lights looks different.

The aperture effect also depends on the brightness, this example uses a quite bright light.

The corona at f/2 is often partly cut-off and I try to avoid it. f/2.8 deals with many artifacts. With f/4 one gets new artifacts, but the spikes are rather nice. Using f/4 often means to compromise the iso value if used hand-held at night. But when this kind of spiky point light is preferred over the f/2.8 rendering, this trade-off is available.

Dimmer point lights might show no corona at all, making the full f/2 aperture usable in some cases even at night.

Chromatic aberration

A single lens element has a given focal length for just one wavelength. Other wavelengths, meaning other colors, will focus somewhere else. Using multiple elements with different properties, one can bring a wider spectrum to the same focal length, but there are trade-offs: Every element makes the construction heavier, bulkier, and more expensive.

As a result, some color fringes are still visible on high-contrast edges. The camera’s Jpeg engine automatically removes smaller chromatic aberration artifacts, but is not aggressive enough to remove all possible color fringes.

For a lens of this size, the aberration is very well controlled and only appears in high-contrast situations and predominantly in edge areas of the frame. Fringes can be removed later on a computer, but I prefer higher f-numbers to avoid, or at least reduce color fringes in advance.

Bokeh quality

The outer edge of bokeh disks is a bit too pronounced. This is bad when sun shines through tree leaves, as the bokeh now generates a busy pattern. When there are just some light sources in the background, the same effects helps to create a nice background.

The X100 cannot provide a perfect, creamy appearance. And to reiterate, certain backgrounds lead to a busy pattern which is bad-looking. But in many circumstances the lens helps to get usable background separation with a pleasant representation of out-of-focus areas. Of course this is a subjective matter, but I like how out-of-focus parts look.

No real macro lens

In close range and with open aperture, the entire image gets soft, loses contrast and appears hazy. This limits open aperture usage in a focus range below 1.5 meters.

In some cases this can still be useful. Applied to the maximum, one can create a dreamy look. This effect quickly wears off and therefore is not a style choice one can use often, but the option is there getting this through the lens instead of a digital filter.

Applied just a bit, for example using f/2.5 for head-shoulder-portraits, the effect is just strong enough to hint at the dreamy look while also helping a bit to conceal some skin issues – lowered contrast can have its use. There is additional sharpness loss in the outer parts of the image, this helps to lead the attention to the center. If one is lucky, this ‘issue’ gets one a gracious portrait.

For best overall sharpness I use apertures in the range of f/5.6 to f/7.1. This is based on experience, not on measurements, please take that with a grain of salt. Even then, the corners of the image are not completely sharp. While the lens otherwise resolves enough detail for a 24 megapixel sensor, I would say that the X100 lens cannot compete with full-size lenses in terms of technical performance.

It is a compact design with good performance where it matters. Macro-wise, one can get as close as 10 centimeters to an object, measured from the outer lens element, but in order to get a usable image, one has to stop down. This is nowhere near the macro capability of a typical compact or bridge camera, but still not bad.

Practical concerns

Because the lens consists of only eight elements, we can assume that the loss of light is proportionally small. In most cases, the lens just performs. In more extreme circumstances, one needs a bit of experience to either avoid optical artifacts, or to use those to create a particular effect.

The X100F lens is the same construction as found in the original Finepix X100. If perfect lens output could be achieved while staying within the size, weight and production cost boundaries, I guess the Fujinon engineers would have done that. I think it is safe to conclude from observation that the X100 lens was not designed for pixel-peepers. Instead it was made to offer a versatile tool in a small package.

Conclusion

Do I wish for a new lens design? Except weather sealing, no, I don’t know what it is, but the lens has it.

Even with optimal settings, photos are not flawless, but the X100 imperfections usually lead to a traditional photographic look. This might be a reason for liking those images.

The X100 results are better than one would expect of a lens of this size, this could also add to the reputation if only because one has lower expectations.

But the real reason for the X100 ‘magic’ is this: The camera is fun to use and therefore used often, producing more lucky hits.

4 thoughts on “How good is the X100F lens?

  1. Stefan Kahlert

    My sample exhibited bitingly sharp center performance but quite uneven sharpness over the field. With land- and citiyscapes, sharpness was quite unpredictable and uneven towards the edges with some areas in- and other out-of-focus that were in the same distance from the camera, mostly infinity. Maybe I got a bad one, though. In the end I found the XF 23mm f2 WR on the X-T2 to have a tiny bit less punch in the center but easier to work with.

    Reply
    1. Arne Post author

      Yes, I had cases where sharpness loss in the edges was worse than expected and others where it was better. Perhaps the lens has a weird field curvature. In most cases, images were still quite usable, I also feel not experienced enough to comment about the X100 lens field curvature.

      Reply
  2. Dr.S

    I had the original X100 and I was satisfied with the pictures taken in good light. What I don’t like is the 23mm (35) lens. Now I use an XPRO2 with 35mm (50) lens but I miss the uniqness of X100 range.

    Reply
    1. Arne Post author

      The 35 mm equivalent lens allows a quite fast aperture while still having a very compact design. On some occasion I also with for a 50 mm equivalent field of view, but that would make it difficult if I need a wider angle.

      Reply

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