XF35mmF2 was announced and released prior to X-Pro2, but the product planning took place concurrently. The fact is, the product planner of X-Pro2 and XF35mmF2 is the same person. Furthermore, the product designer is also the same person.
Here is the "Design spec sheet" for the product planning of X-Pro2. You can see that the XF35mmF2 was always attached to X-Pro2. Likewise in the planning sheet of XF35mmF2, the X-Pro2 was dominantly present. Just as you figure it out, X-Pro2 and XF35mmF2 were planned and developed to be the best match for each other.
Up until the announcement of X-Pro2, we have been asked on numerous occasion, "When will the X-Pro1's successor come out?" And we have replied "When we see an advancement in all aspect." The answer did not only mean the sensor, processor, finder, and etc., but also a best matching standard prime lens.
When we talk about XF35, we cannot ignore the presence of XF35mmF1.4. It is the best-selling prime lens. So is it perfect? Not necessarily.
The speciality of the lens is the high image quality it delivers. It contributed very much to make the X Series known for its image quality. However there were a few items that could have been better. You can think of XF35mmF2 is the answer to these needed improvements.
The concept of XF35mmF2 is to make the lens for snap shooters.
First, XF35mmF2 is skinny. It's not small, but skinny. It only measures 60mm in the largest diameter. If it is smaller than 60mm, then everything would fit within the body mount. It looks nice and clean when the lens is attached to the body.
The large diameter lens is a very attractive choice, but one cannot behave naturally, if such lens was pointed at him/her. Snap shooting is not about taking a picture of a stiffened expression, or a subject striking a pose. The skinny lens also minimize the vignetting in the OVF. Everyone would like the clear view.
XF35mmF2 is also quiet. As mentioned here, X-Pro2 is about the sound. If the lens is noisy, then it is pointless to have a quiet camera. The lens also needs to be low-key. It also has to be fast. X-Pro2 is a weather-resistant camera, so the lens also has to be one.
So with all these requirements in place, we look into how we can realize them. Generally speaking, the standard lens with F2 is a backup lens for F1.4 lens. Often times, we see a compromise in the quality. But this is not the case for XF35mmF2.
In order to realize the requirements, we carefully crafted the optics and mechanics. If you look at the number of lens alone, XF35mmF2 comprises 9 elements in 6 groups (including two aspherical lenses). This construction is more luxurious than XF35F1.4. The aspherical lens is really effective for the compact optical length.
We also look into the mechanical parts of the lens. In order to meet the requirement within the small lens barrel, metal barrel with high rigidity is used. We minimized the size by making each parts with multi-purpose. XF35F2 uses all metal parts for the exterior. Like previously mentioned in this article, In order to process the fast AF, actuator and micro computer are installed.
Other criteria had to be met to be in the XF lens lineup. To have 1/3 step aperture ring, new click mechanism was developed. Two balls are positioned, so that there will be an assuring click even though the rotation distance is short.
"So, is the XF35F2 better than XF35F1.4?" you may wonder. And there is no definite answer to this.
If you want the "X image quality," then you should consider XF35F1.4. If you are in search for "Snap shooting X," then XF35F2 would be your most preferred choice. This is an standard lens with the most commonly used angle of view. It never hurts to have wider options to choose from, with wider range of characteristics.