It is now more than two and a half years ago that I published a review of the Camdiox/Roxen focal reducer for Fujifilm cameras. I never suspected that this particular blog post (and a couple of follow-ups) would become so massively popular. During the years it gathered views in the hundreds of thousands and, even today, attracts lots of visits almost daily.
This is a solid proof that Fujifilm users (and mirrorless shooters in general) are particularly interested in such devices. What started some years ago by Metabones and their famous Speedboosters, is definitely not a fad but a solid and very useful option.
The Camdiox/Roxen was basically a generic copy of the Metabones, and belongs to the first generation of focal reducers. The exact same device was sold with different branding, and I do suspect that the first generation Lens Turbo was perhaps one of them. Or, in any case, it provided about the same level of optical performance.
(In case you’d like more information about how focal reducers work please check this previous blog post. Everything there still applies).
Things are radically different now, and very much improved with the focal reducer I review here, which is the ZYOptics Zhongyi Lens Turbo II. In case you live under a rock during the last 3-4 years, this is the company behind the Mitakon brand, which has already become extremely popular with mirrorless users, having introduced a considerable number of high-performance lenses.
Naturally, the first thing I would like to see is how much the optical performance would have been improved. Another consideration was that I could now test a focal reducer using the latest and greatest Fuji cameras, with the latest sensors; but also with better manual focusing tools. As a reminder, back in 2015, I could only do tests with the 16mp sensor cameras.
The Lens Turbo II version I tested was the Nikon-F version; there are also M42 and Canon-EOS versions available for Fujifilm. As I analyzed in the older articles, the Canon version is the most versatile one, since you can use not only Canon lenses but also M42, Nikon-F, Pentax-K and others, via the use of “dummy” additional adapters.
That said, the Nikon-F version of this adapter is a very well made piece of kit, which also happens to be quite versatile. There are myriads of very good to absolutely top-notch lenses made for the Nikon-F mount, through the years, both by Nikon and several third party lens manufacturers. Apart from the Nikkors, think of Zeiss or Voigtlander and you get the idea: both vintage and modern design lenses can be adapted easily. The Nikon adapter also features an “aperture” ring for controlling G-type lenses, thus it’s not limited to aperture-equipped lenses.
I used the adapter with four great, vintage Nikon manual lenses:
- Tamron Adaptall-2 28mm f2.5
- Nikkor 50mm f1.4 ai
- Nikkor 105mm f2.5 ai
- Nikon-E 100mm f2.8
I shall expand upon the optical characteristics and performance of each lens in part 2 of this report. I believe they are characteristic of what someone may usually have in hand to adapt, both for photography and video. At this point, I would like to thank my good friend Ioannis Triantafyllou who lend me (for a long enough period of time) both the adapter and the 50mm and 105mm lenses; thank you for the patience dude!
First impressions from using the adapter were extremely favorable: it is both very easy to use (i.e. transparent) and IQ is evident from the very first moment. I dare say that, with an adapter such as this, vintage lenses get what they deserve, in their new role in the digital realm. There is always a concern with any converter adapter that contains optical elements, that IQ will be degraded. Indeed, with the first generation of “copy-cat” focal reducers, there were some small issues, such as flares, chromatic aberrations and such. The Lens Turbo II has no evident flaws that I can find. It seems that the new optical formula (4 lens elements in 4 groups including 1 extra-low dispersion element, according to the company specs) is playing well, at least with the lenses tested.
As always, there is the immediate great gain for APS-C cameras, of one stop in light gathering plus one stop of DoF. Please pay attention to the previous statement. The focal reducer gives both one stop of light and makes the DoF approximately the same as a full frame camera. I know there exists an increasing number of morons on the internet, claiming that “full frame cameras gather more light”. No. No, they don’t. Stop spreading utter nonsense. We would need a different light-meter for each sensor size if this was the case. Enough said.
As far as FoV is concerned, the Lens Turbo II has a “crop” factor of 0.726. Let’s do some basic arithmetic: the 100mm Nikon would “become” like a 76.2mm lens for APS-C, and have an effective aperture of f2. That means that multiplying by the sensor crop factor, we eventually get a ~115mm FoV, with a DoF of f2.8 in FF terms, but also have one stop faster shutter (the one stop of light gained, see above). Thus, in practical terms, you can calculate for a 1.15X “crop” factor, if you need to “visualize” FoV in relation to FF digital or film cameras.
This would be all for now; please find a first hearty image gallery below. The lens used on each occasion is labeled in the image title (click on the thumbnails for a full image). Photos were shot with both the X-Pro2 and X-T2. Hope you enjoy them!
In part 2 of this review, we’ll talk in more detail about operation and image quality, with the Fuji cameras, and, of course, have even more sample photos. Please stay tuned, and also share and comment in the appropriate section below!
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