Konica Hexanon AR 57mm f1.2 Lens Review

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Let me tell you – I am incredibly thrilled to have this Konica Hexanon AR 57mm f1.2. More so, because I bought it by chance – saw a good deal on eBay and took it, hoping it would turn out to be a good one.  I was not wrong! This lens turned out to be exceptional in a lot of ways. First of all – it is the most radioactive lens that I own, peaking at over 37,000 counts per minute. Secondly, it produces some of the most striking images – detailed, sharp, with silky bokeh. It’s not cheap, especially compared to other Konica lenses, but it is still less expensive than the other fast lenses. 

Konica Hexanon AR 57mm f1.2 - Side view
Konica Hexanon AR 57mm f1.2 – Side view

Build quality and construction

This lens is like a tank — robust and hefty piece of Japanese engineering featuring world-class glass. One look at the imposing front element proves this lens means business. Konica Hexanon AR 57mm f1.2 was at the top of the standard lens lineup, aimed at professional use. And it shows. 

The rear element is unique – part of the glass is cut to accommodate the aperture pin. Similar to the Tomioka 55mm f1.2, but in a straight line instead of a curve. The cut-off shape can show up in the bokeh, if the lighting is right, which might be a potential issue for some people. 

Aperture has half stops, making it easy to get the desired value. Blades are snappy and well made. The ring is not too damped, and can feel a little loose – it’s easy to go too far when changing the aperture.

I prefer a focal length which is slightly longer than 50mm for a standard lens. In this case, 57mm is just right for me. Focusing is easy, and smooth – there is ample sharpness to show the clear plane of focus using the focus peaking. Some softer lenses don’t trigger the peaking, and they are never truly sharp, especially wide open. 

Konica Hexanon AR 57mm f1.2 - Back view showing the cut off element
Konica Hexanon AR 57mm f1.2 – Back view showing the cut off element
Konica Hexanon AR 57mm f1.2 - Front-side view and lens coating
Front-side view and lens coating
Konica Hexanon 57mm f1.2 Specifications and Diagram
Specifications and Diagram

Image quality 

I can’t take this lens off the camera! Figuratively – in reality, I take it off after shooting to protect the camera’s electronics, as the lens is quite radioactive. The thorium in the lens irradiates the images with life. A subtle yellowing of the elements acts as a warm filter. Some people decide to ‘de-yellow’ the thorium glass, but I prefer to keep it. There is plenty of clear modern glass on the market and only a few warmly glowing thoriated lenses from the bygone era. Nobody makes them anymore, except for the military. 

Even the weird cut-off bokeh shape does not bother me too much. There are other lenses for that sort of photography, where the bokeh becomes the main subject. Konica Hexanon AR 57mm f1.2 is not suited for that type of photography unless you want to see the cut-off circles for some reason. However, it manages to blend the background into a smooth soup of colour in a very pleasing way when there are no highlights.

Image quality wide open is pleasing – acceptably sharp, albeit a little on the softer side. OK for portraits, but could be too soft for other subjects. Sharpness improves dramatically in the centre of the frame from about f2.8, while still retaining the excellent bokeh rendering. From f4 most of the frame is pin-sharp. Most of my photos are within this range unless I need a more significant depth of field. 

So yeah, to sum it up – I appreciate the images this lens produces time and time again. 

Konica Hexanon AR 57mm f1.2 at about f2
Konica Hexanon AR 57mm f1.2 at about f2

Adapting Konica Hexanon AR 57mm f1.2 to Mirrorless

Konica AR mount flange distance limited the usage of the excellent Konica glass on a modern DSLRs. Flange distance was way shorter than Canon or Nikon, which meant there is no space remaining for the adapter. Konica lenses would either need special corrective adapters which I am unsure ever existed. And without a viable adapter, Konica lenses would either not focus to infinity or even hit the camera’s mirror. 

Luckily, that is no longer the case, and we can readily adapt the Konica AR lenses to most mirrorless cameras, like my Canon EOS R. 

I use a Fotasy Konica AR to EOS RF mount adapter. It was affordable – cost about 20 USD from Amazon USA. The quality is excellent, though – there is absolutely no play between the lens and the adapter, or the adapter and the camera. Everything is snug and firm. Exactly what you need when mounting a precious lens such as this.

Fotasy Konica AR to Canon RF adapter
Fotasy Konica AR to Canon RF adapter


Konica Hexanon AR 57mm F1.2 is radioactive – more than all other lenses measured. A reading of the lens’ front is about 37,662 CPM and 26,000 CPM at the back. Typically, lenses have thoriated elements either at the front or at the back of the lens, unlike Konica Hexanon AR 57mm f1.2, which is radioactive from both ends. Thorium is added intentionally to improve the optical properties of the glass. Konica even boasted about it in their promotional material.

Not the least important is the production of several types of optical glass, many of which embody rare earths. Exotic elements such as Thorium, Lanthanum and Zirconium are added to glass mixtures to create the high refractive indexes necessary in sophisticated lens designs. Selection of premium quantities of glass from the large glass pots, stringent spectrophotometric tests after stress and strain checks provide the valuable raw glass for ultimate use in lens elements.

Apart from a few precautions, radioactive lenses are generally safe to use, after all – they are consumer devices. You can read my article about radioactive lenses to find out more. 

Konica Hexanon AR 57mm f1.2 - Front element emitting over 37,000 CPM of radiation
Konica Hexanon AR 57mm f1.2 – Front element emitting over 37,000 CPM of radiation
A reading of over 26,000 CPM at the back element
A reading of over 26,000 CPM at the back element

Price and availability

Bought for £450 from eBay UK. You can also find it for about €500 on eBay DE, and $600 on eBay USA. Look around, and be prepared to wait a litte until you find one appropriately priced. It is not too rare, but finding one in a good condition for the acceptable price can be a little difficult.

Similar lenses

Canon FD 55mm f1.2 S.S.C.


What a lens! Konica Hexanon AR 57mm f1.2 ticks all my boxes and I don’t intend to sell it. I prefer the images taken with it over a lot of other vintage lenses. Must be the thorium! This lens is a 5 / 5 for me.

Have you used Konica Hexanon AR 57mm F1.2? Let me know what you think about this review and leave a comment!

Sample Images

Shot at about f2
Shot at about f2
Shot at f4
Shot at f4
Plenty of sharpness and a silky smooth background
Plenty of sharpness and a silky smooth background
The hexagonal aperture shows when the lens is stopped down
The hexagonal aperture shows when the lens is stopped down
I particularly like the background rendition of this lens
I particularly like the background rendition of this lens
Konica Hexanon AR 57mm f1.2 is extremely sharp when stopped down
Konica Hexanon AR 57mm f1.2 is extremely sharp when stopped down
The thorium "warm" filter effect
The thorium “warm” filter effect
Plenty sharp when needed
Plenty sharp when needed


20 Replies to “Konica Hexanon AR 57mm f1.2 Lens Review”

  1. Very good review Mantas. Beautifully presented, informative. Excellent images. I enjoyed reading it. Never had any experience with this Hexanon. I own Minolta Rokkor-PG 58mm 1.2 (non radioactive) witch is my favorite portrait lens.

    1. Thank you Romas, glad you liked it! I also have the Minolta you mentioned, but my one is Radioactive (I specifically searched for that version). I will write about it as well, at some point!

    2. Hi mine is different and AE nor EE, is it better and what differences ? anyone know ?

      Am getting an EOS EF adaptor for mine including a reducer with no infinity issue

    3. Thanks for this review.
      I’m wondering if the cut off at the rear of the lens is just on the mount or in the glass itself?

  2. Mantas, I’m the owner of a copy of this lens since October last year. It’s both in excellent condition (the last version, probably somewhere in the eighties) and at around the price you indicated. It’s is easily one out of my 3 or 4 most expensive vintage jewels (Ultron and Quinon being the others, with a Westagon 50 in the pipe-line). Still, I don’t use it that often, out of fear to break or loose it !
    I still don’t possess an alpha 7, so my alternatives are an old Olympus E-520 (no adapter), an Olympus OM-D (FMT) or my faithful but time-battered D7000. The Fotodiox infinity-lens is good enough to allow this equipment to be used. It is not adequate at anything below f/2,8, and may occasionnally engender a central flare and discoloration, especially if you (by accident) overexpose a bit. But even so, this lens is a joy to use. I’ve had two walks in the Alps today, took about 200 photographs and am quite pleased. I admit I tend to correct the « over-yellow » color at post-processing. I also shoot with both Hexanon 50 mm (1,4 and 1,7), Hexanon 52 mm f/1,8 (30 euros!) and Hexanon 57 f/1,4. Yes, there is a bit of a collector in me, but I use ALL my lenses as regularly as I can. I’m not a professional but I take pictures – almost – every day (at least 355 days/year, that is). So the question is : does one need to pay so much for this lens on modern digital cameras ? The answer is straightforward : technically and optically : NO. But I wanted just ONE f/1,2 and this is the one I picked out. And it gives me a lot of pleasure, and, as a bonus, nice pictures as well.
    I like your reviews very much, they are sincere, fun to read and intelligent. Just one last comment : I’m knowledgeable in physics, to a certain degree (both optics and radioactivity), I have got a medical education, my mother (91 years old and still OK) was an eye-surgeon and my late dad a … radio-protectionist. So, I know a bit about this subject. The topic of radioactive lens is a joke. The only caveat is about microscope eye-pieces with thoriated glass. The cornea and retina of the observer remain very close to the ocular lens for HOURS in a row. But these microscopes are not used any longer. So, who cares ?
    Thank you for your entertaining notes.

    1. Thank you so much for your dedication to leave a long reply! It’s nice to know that people find these reviews interesting and helps me find the motivation to write more of them. You have some amazing experience with radiation and physics. Could you spend a few minutes to read and comment on the radioactive lenses article I posted recently? I would really appreciate your feedback and input. You can find it in the articles section (easy to find – I only have one article).

  3. I tried twice to leave a comment by way of a “cut & paste” method from my word processor. It won’t appear.
    Or maybe there is some unnotified moderation ongoing?

    1. Thank you, the reason why the comments did not appear automatically was the web server cache. It takes a few hours to refresh, and for new content to appear. I may need to tweak it, to make it a little faster reacting. Thank you for feedback!

      1. Now the comment is there. Thanks. The “radiation issue” is an interesting one; I will go and read your article. I just went through your Ultron paper … I used mine this morning (an M42 version … on a D7000 as my MFT needs to be repaired, stuck curtain, a chronic fault in some Olympus cameras). Anecdote: I wanted one, but I’m not a rich man. I finally found one that pleased me for the amount I could afford. After a few months, I was prudently retightening the screws of the mount (I always do). There is a small plate covering a hole which served some automatism or electrical purpose in older Zeiss cameras bodies. Has two tiny screws in it has well. No sooner had I just touched it … it was swallowed in the core of the objective. The damn thing was spring-loaded! I – with fear in my guts – opened the bottom, just, and could extract (surgical tweezers) the bit and un unidentified piece of plastic as well. I figured out where it (they) should be located but had to give up after two hours of sweating and cursing. Rather than leaving the hole wide open, I stuck a piece of thin adhesive tape over it. All works well … Some amateur photographers do it for the sheer pleasure. I suppose I’m out for Adrenalin!

    1. Thorium only makes this lens more special! I don’t think they advertised it that time. I only found a small paragraph that mentions it in the Konica materials. Nonetheless, a fascinating lens!

  4. I’ve had this excellent lens, among a few other f/1.2 standard lenses. I found however, that they hardly offered any benefit over some of my f/1.4 lenses: they’re all able to completely anihilate the background. And that’s why I eventually sold them again. Their high value usually generated enough money to buy a few other interesting lenses. But I must admit that handling these bulky light giants is quite a pleasure.
    My favourite fast vintage lens until now is the Mamiya EF 50mm f/1.4, I believe it also exists in Mamiya’s CS line. It’s quite sharp wide open, with silky smooth bokeh. Its looks are however quite underwhelming next to your Hexanon. I enjoy reading your reviews, and look forward to reading more of them!

    1. Hi Casper, thank you for your kind words and the recommendation of the Mamiya EF 50mm f1.4. I really like the other Mamiya lenses such as the old Mamiya Sekor 55mm f1.4 and the 55mm f1.8 from the same period. I will definitely check this one out too!

  5. Great writeup – very well done. This lens has simmered just under the surface for many shooters it seems for quite a long time. I only picked one up about 3 years ago and in that time it’s become one of my all-time favorite, in the top-3 quite easily. Mine is one of the earliest, with silver-ring, EE, thorium impregnated. I adore it for many reasons you described so well. I have an early Hexanon 57/1.4 as well, and it’s lovely but an entirely different (compact) beast. Other notable fast normals I’ve had or have include the Pentax K 50/1.2 (my oldest of well over a decade but considering parting with it), the legendary Minolta (which I did appreciate but sold on – I just never used it, preferring others), the 67 105/2.4 early radioactive Takumar version (medium format but nonethess… it’s just lovely, though I’m not sure I hold it in quite the same high regard many do), and the 7-element radioactive Takumar 50/1.4 (needs no introduction). I also only just recently acquired and earlier Topcor RE 58/1.4 and first impressions are fantastic (but it has issues that need to be addressed before I really dig into it further).
    At any rate the Hexanon 57/1.2 joins the ranks of “lenses I’ll never part with”, which also include the Pentax FA 31/1.8, as well as the Hexanon UC AR 28/1.8…. and a couple others. I’d also throw into that list both the 45mm and 38mm Hexanons fixed to the Konica AutoS2 and AutoS3 repectively and would love to someday adapt them for mirrorless use but refuse to remove them from their homes.
    In any case… great little writeup. I enjoy these. Cheers.

  6. Great review! I got the lens last year and wanted to mention that the rear glass is not cut! it is fully intact, it just has this cover/sleeve (held by 3 small screws) with the pin that you do not need. You can remove the cover (and optional) the mount in 1min and just spraypaint the interior of the mount ring black to hinder internal refections. Removing that pin-cap exposes the silver ring of the mount to the lens internal, when focusing near there is a signifcant gap between the rear element and the silver ring, which can cause internal reflections (red flares on my black EE version). In any case I would definetly remove that, no one needs it. I use it also on my autoreflex T3 and it fully works. I use a cellphone app like many others as a lightmeter so I do not need that pin at all.
    Take care guys and enjoy that great lens without cut-bokeh

  7. Sadly one 1.2 version of Konica AR I had was totally horrible. Very undharp in all areas
    Maybe 55 or 50/1.2 couldn’t recall

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