The Unique Nikon Nikkor-Q 25CM f/4 for Bronica S2/S2A

Most people will never see, hold, or use the Bronica S2A’s Nikon Nikkor-Q 25CM f/4 lens. In fact, Tony Hilton’s authoritative Bronica S2A book “Bronica: The Early History and Definitive Collector’s Guide” lists only five known copies. Through research, I found seven others not listed in his book and I suspect, at most, 25 copies of this lens were made and, now, far fewer exist.

I bought my copy of this lens in 2017, lucked into it at an established and successful camera shop that didn’t know what they had. I didn’t know what I had bought either, but I wanted a telephoto for my Bronica, and this fit the bill. That said, when I inspected it, I almost returned it. You see, the lens had been disassembled at some point and reassembled incorrectly. The lens could not focus to infinity unless I unmounted it from my camera and held it in front of the camera, basically free-lensing.

Still not knowing what I had, I disassembled the lens and found that the issue was in how the focus ring had been re-attached to the lens. A quick adjustment to the focus ring placement and I was able to infinity focus. I checked the lens elements to make sure they were seated properly – which they were – and re-assembled the lens. It wasn’t until I began looking for a lens diagram online to make sure that I had assembled it correctly, I started to realize how rare the lens was.

Nikon made Bronica’s medium-format lenses for many years, creating lenses for the system from a 30mm fisheye to a 1200mm telephoto. During that period they also made some oddities, including this 25CM f/4 lens.

It was a lens originally designed for the Leica LTM system and designed to house a reflex box between it and the LTM-threaded camera, these lenses produced an image circle large enough to cover 6×6, although as you’ll see in the images in this article, the lens exhibits a strong circle with coma swirl beyond that. The birds on a wire image below is a great example.

For rare lens nuts reading this, Tony Hilton lists serial numbers 273365, 273414, 273495, 273631, and 273743. I’ve also identified 273223, 273246, 273320, 273500, 273614, 273756, and 274011. These serial numbers span a 788-digit range. They appear to be inclusive of the pre-set versions of this lens made for the Leica LTM system, too, and that stands to reason because they are (insofar as I can tell) the same lens optically, with a different rear mount and focusing ring. Most of the copies of this lens were made for LTM and most of these lenses that you see for sale will be for LTM-threaded rangefinders.

In his 2007 book “The Complete Nikon Rangefinder System” Robert Rotoloni indicated that about 700 of these lenses were made with Type II LTM reflex housings and an additional 100 with Type I housings (Type II housings have 45-degree viewfinder and Type I have a 90-degree).

Additional, uncited, reports in camera forums indicate a conventional wisdom that 1,700 of the pre-set lenses were produced (the Bronica versions fall into this category). I have not yet found a source that supports that number, however. Also, the LTM versions have a different rear mount and the two versions, Bronica and LTM, are not interchangeable.

Including mine, I know directly of six of the 12 copies I’ve identified of this lens and only one other is usable, the rest have lost their large bayonet adapter ring. You may never see another first-hand article about this lens with photos taken by the author.

A few reasons exist that can lend a lens the title of “rare”:

1. They were prototypes.
2. They were too expensive for most people and so very few were made.
3. They performed badly and were discontinued quickly.

The Bronica version of the Nikon Nikkor-Q 25CM f/4 falls mostly in the third category and somewhat in the second. As mentioned previously, outside of the 35mm image circle area*1, the Nikkor-Q 25CM f/4 is defined by its severe field curvature, coma, and distortion. These issues are largely rectified by f/11 or f/16, where the lens performs its best, but at those smaller apertures, another issue manifests: focus shift.

*1 This lens was the same optical design for the 35mm LTM system and the Bronica 6X6. So, theoretically, an LTM lens could have the elements swapped for a Bronica and no-one would be any the wiser, note that I’ve not tried that.

As the aperture closes, the lens’ focus point shifts. This is especially noticeable on close subjects, where the focus can shift many centimetres. Focus shift is a common issue with older lenses, especially telephoto lenses.

For handling, this lens handles well compared to many of its contemporary pre-set counterparts. The focus is smooth and some versions, not mine, have a focus-assist lever that pops out of the milled focus ring. This silver bar can be placed between fingers to improve handling.

Speaking of the focus ring, the grip is large and the milled finish makes it easy to hold. This lens exudes the type of quality in build seen in only the top-tier of lenses made today. Using a pre-set lens slows the photographic process, forces the photographer to evaluate the image in greater detail.

Pre-set lenses today may seem like archaic technology, but some Chinese lenses like the KamLan 50mm f/1.1 use a similar approach with an uncoupled aperture. The Nikkor-Q 25CM f/4 here only has a single push-pull aperture control ring but generally speaking, pre-set lenses use two rings: one that sets an aperture stop and one that controls the aperture.

Instead of selecting the aperture via a ring and having the blades close-down immediately upon exposure via a mechanical coupling with the camera, the photographer “pre-sets” the lens to their chosen aperture first by way of the aperture stop ring. That means that the aperture control ring cannot close past that stop and the photographer can stop down the lens before exposure without looking to make sure that the aperture is set correctly — the stop ring does that part. If this concept is hard to picture, the gif below should illustrate the concept well.

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Once set, every possible aperture from wide-open to the pre-set aperture can be selected using a secondary ring that moves from the max aperture to the one selected. This means that if a photographer wants to bracket two images, stopped all the way down to the stop and one that’s slightly wider, that can be done easily.

For those of you who like vintage lenses for videography, pre-set lenses are an ideal option. If, unlike the Bronica S2 or S2A, the lens is mounted on a camera with automatic exposure (aperture-priority,) pre-set lenses can be a great benefit. They allow the photographer to visualize the focus as the lens stops down. In video work, the aperture’s perfect circularity (a typical, but not always true hallmark of pre-set lenses) creates very pleasing transitions from shallow to deep focus. The use method described above gives you a completely stepless aperture.

One other advantage of a pre-set lens is that if the aperture has oil it’s no issue. Because the camera does not have to stop the aperture down, an action that is inherently dainty and that can be disrupted by even a small amount of oil on a typical lens’ aperture, and because the photographer stops down the lens with their own hands, the effects of oil on blades are negligible.

The images in this article display all of this lens’ myriad faults and flaws, including also general softness and an overall lack of contrast. The only great qualities about this lens are its absolute rareness and the out of focus characteristic delivered by the circular-at-all-stops pre-set aperture.

That said, I still love using this lens not despite of, but because of, all these flaws. Taking great photos with a lens like this is a challenge for every shot. Sometimes it pays off, sometimes not. Lenses like these are hard to master; they handle like a McLaren P1 flat-out, devoid of forgiveness or assistance.

I don’t shoot with this lens so often now. The rarity and the risk to it mean that I only take it on select hikes or photoshoots. More often, I use a Komura 300mm f/5 that has a removable focusing helical that can also mount a Komura 500mm f/7 (and a 400mm f/6.3, but I neither have, nor would I use, that lens.) The Komura lets me carry two telephotos for my Bronica that, combined, take up little more space than the 25CM Nikkor-Q.

I can’t, in good conscience, recommend buying one of these. Finding a large bayonet adapter ring, if it’s missing, will be almost an impossibility. And these lenses cost far more than they should, especially considering most of the purchase price is for conversation value. But learning to master a lens like an old pre-set with focus shift and optical problems that simply could not be surmounted by mid-century engineers with slide rules and pencils, that experience I highly recommend.

Learning to take good photos with challenging lenses will make your use of good lenses that much better. Nothing teaches a photographer how to recognize a lens’ sweet spot quite like finding that spot on a lens that almost lacks one.

For more on the Bronica S2A and to see additional photos taken with the lens in this article, check out my YouTube video review for the Bronica S2A.

Thanks for reading!

~ David

Nikon Nikkor-Q 25CM f/4 technical specifications

Manufacturer	Nippon Kōgaku Tōkyō K.K.
Mount	Two-part mount with interchangeable adapters for: Bronica S2/S2A Leica LTM Nikon F
Designation	Nikon Nikkor-Q 25CM f/4
Focal Length	25cm (250mm
Max. Aperture	f/4
Min. aperture	f/32
Aperture blades	15 (circular throughout the range)
Design	4 elements in 3 groups
Floating Elements	No
Closest Focus	300cm
IR Focus Mark	No
Filter Diameter	68mm
FilterType/Mount	Screw-in (mounts on rear element)
Length	133mm
Weight	1042g