Minolta Auto Tele Rokkor PF 100mm 1:2.0 – AR II – review

Published by Tony on

Minolta Rokkor PF 100mm 1:2.0 Auto Tele (AR-II) engraved as “Minolta Auto Tele Rokkor-PF 1:2 f=100mm” lens review

  • Official classification: SR
  • Collector’s classification: AR II

This is another lens at the top of the wish list of many photographers and collectors. Photographers are drawn to its speed and portrait focal length, while collectors are drawn to its rarity and some traits which are unusual for Minolta’s products.

Minolta Rokkor PF 100mm 1:2.0 specifications

# in minolta.eazypix.de index 144
Name engraved on lens AUTO TELE ROKKOR-PF
f[mm] 100
A max [1/f] 2
A min[1/f] 22
Lens design [el.] 6
Lens design [gr.] 5
Filter thread Ø front(rear)[mm] 62
Lens Shade D62NA
closefocus[m/ft] 1.2/4
Dimension Ø x length [mm] 66×63
Weight[g] 425
Year 1961.02.25
Style AR II
Code No. (ROKKOR-X) or Order No. 560 or LOC-B
Notes

More data

Floating elements NO
Aperture blades number 7
Confidence in the test results of reviewed copies Enough high
Reviewed Lens SN: 1300751

Historical note

By one of the popular collectors classification this lens has two main incarnations – AR II and MC I. This review – strictly about AR II.

(There is also AR I version is mentioned on the minolta.eazypix.de but it is a mistake, only AR II and MC I are existed. Please correct me if I’m wrong) 

Interesting detail: there is a misprint on the box: “FP” used instead of “PF”, the photo was borrowed from here:

This is not the reviewed copy on the picture above. Also I have to say that reviewed one 100/2 was come with metal front cap and with black leather case. Which combination is correct I don’t know, probably both (need more information):

About the radioactivity

This lens was a huge surprise for advanced collectors. The fact is that for a long time it was believed that Minolta produced only two radioactive lenses – Rokkor 28/2.5 and some early Rokkors 58/1.2 – you can read about these lenses in the relevant reviews. By the way, there is a steady rumor on the Internet that the early Rokkors 85/1.7 are also radioactive, but this is not true – not a single case has been recorded in reality.

So, on June 29, 2022, Darrell Owens entered the collectors group on Facebook and said the following:

“A couple of weeks ago I took some photos of my probably most-prized Rokkor… an early and radioactive 100mm F2.”

Such the mention about radioactive Rokkor 100/2 AR-II made the community nervous (better to say – the community was exploded). But very soon, we got information from Maury Jacks and Han Fiasco, who quickly measured their lenses and found out the following,

Maury Jacks:

“Just wanted to let you know that my preliminary tests do show radiation in all of my copies”

Han Fiasco:

“Here are the results of the radioactivity of 15 100/2 lenses.
All values of the rear of the lens.
AR II 1200134 1.87 uSv/h
AR II 1200278 1.95 uSv/h
AR II 1201004 2.78 uSv/h
AR II 1201437 2.22 uSv/h
AR II 1201630 2.61 uSv/h
AR II 1201660 1.97 uSv/h
AR II 1201748 2.07 uSv/h
AR II 1201978 2.08 uSv/h
AR II 1300499 1.96 uSv/h
AR II 1300806 1.78 uSv/h
AR II 1300911 2.11 uSv/h
MC I 1310033 2.62 uSv/h
MC I 1311134 0.10 uSv/h NOT RADIOACTIVE!!
MC I 1311494 2.24 uSv/h
MC I 1311573 0.10 uSv/h NOT RADIOACTIVE!!”

(Should I say “thank you” to all these guys? Of course, and I do it.)

Just imagine – 61 years have passed since the release of the lens. Such stories with an unexpected ending make the measured life of collectors a little more exciting.

The reason of this surprise looks simple – despite being radioactive, these lenses do not turn yellow. Until now I have come across or read about radioactive lenses mostly with a yellow tint. Although, yes, I suspected that a yellow tint was optional, since radioactive impurities in glass can be of different types, but Minolta’s image was superimposed as a company that rarely produced such lenses. In principle, nothing has changed – before they had 1.5 of these models, now another half of the model has been added (you remember that not all copies are radioactive).

According to other posts from Han Fiasco, who checked some more of his Minoltas huge collection, no more surprises were found.

(By the way, I’m wondering – Japanese collectors and photographers didn’t know about it either? Or is this news only for collectors from other countries?)

Classification (briefly)

If you are a photographer, you can safely skip this part.
For those who are collectors, I will simply describe the main points so that it would be more convenient for you to dig further. Due to the rarity of this lens, there is really little information about it in open sources, so please contact advanced collectors with questions.

This is the list of signs by which lenses may differ:

  • Serial numbers started from 12 or from 13 (12xxxxx or 13xxxxx)
  • Stop down lever is absent or presented
  • Aperture ring with or without numbers
  • LV numbers are listed or not
  • The F-values increase in reverse direction or the normal direction of all the others Minolta lenses or in the normal direction of all the others Minolta lenses
  • “Lens made in Japan” inscription is on the back of the lens or on the front ring
  • “Lens made in Japan” inscription on the back of the lens – is not painted or painted in white

So, collectors distinguish approximately seven modifications of the AR II version based on this list. The word “approximately” is used because there are references to lenses that may not be real, but have a chance to be so.

In all the reviews on this site, I specifically do not make direct copy-pastes of messages from those collectors who have done their own research. Only if I get express permission. This is a common courtesy to other people’s achievements. I repeat: if you want to study the classification and historical issue in more depth, then please refer to the primary sources among collectors.

Minolta Rokkor PF 100mm 1:2.0 lens exterior

Minolta Rokkor PF 100mm 1:2.0 mounted on camera Minolta SR-7

Very authentic set – the camera and lens could be purchased at the same time

Lens shade

There is some confusion about lens hoods for this lens.
Firstly, the D65KA indicated on the “minolta.eazypix.de” looks like non-existed in reality, so I fixed the specifications in this article because of the next great advice by Andrea Aprà(c):

“Apart from that this lens shade appears only in the literature and no one has ever seen it in reality, in any case I would replace this with the more well-known lens shade with code D62NA.
Then we could discuss which of the two editions (the first is conical and the most recent is cylindrical) is the one compliant with the lens presented here with the LMiJ writing on the front ring. Personally from what I have seen it is the cylindrical model.
Unfortunately this is one of the sad cases where Minolta uses the same code for two different objects.”

“…However, it is certain that only the cylindrical D62NA exists for the MC I model, and that for AR II non-LMiJ only the conical D62NA exists.”

I was not able to find a lens shade for the review, so, these are the “images from somewhere on the internet”:

There are a few more details can be found here.

Minolta Rokkor PF 100mm 1:2.0 sharpness

Сlose-distance resolution test, minimal distance

Testing methods description

  • Target: 10-15 cm picture, printed on glossy photo paper
  • Distance: 1.7m
  • Camera: Sony A7II (24mpx, full-frame, tripod, remote control). M-mode, ISO fixed, WB fixed, SteadyShot – OFF.
  • The test was repeated for every F-stop on every focus position with manual focus adjustment for each shot. That is to avoid the effect of field curvature.
  • RAW processing: Capture One, default settings. All quality settings – 100%. Crops – 300×200 px

Original target image (printed in horizontal orientation on 10cm X 15cm glossy photo paper)

Scene preview

Test results

Minolta Rokkor PF 100mm 1:2.0 - resolution - close distance

Long-distance resolution test

Testing methods description

  • Target: cityscape
  • Distance: > 200 meters to center focus point
  • Camera: Sony A7II (24mpx, full-frame, tripod, remote control). M-mode, ISO fixed, WB fixed, SteadyShot – OFF. The focus point is on the center only.
  • RAW processing: Capture One, default settings. All quality settings – 100%. Crops – 300×200 px

Scene preview

Test results

Minolta Rokkor PF 100mm 1:2.0 - resolution - far distance

Minolta Rokkor PF 100mm 1:2.0 aberrations

Vignetting

Geometric distortion

Coma aberrations

Chromatic aberrations

Long-distance bokeh

Test #1

Test conditions: the lens was focused on minimal distance on the scale (1.2m), buildings are on “infinity”-distance.

Test#2:

Test conditions: lens was focused on 3.0m

Light bubbles bokeh – long distance

Test #1

The lens is on the minimal focusing distance 1.2m, lights are on infinity (cityscape)

Test #2

Test conditions: lens was focused on 3.0m

Minolta Rokkor PF 100mm 1:2.0 – final conclusion

Should I recommend this lens to Collectors? Of course yes. It has so many wonderful unusual sides that it is impossible to pass by. I even think that after the story of the discovery of radioactivity, this lens will become even more valuable.

The question is more complicated – is it worth recommending it to photographers? You can see the test results yourself. The secondary features are in order – vignetting, geometry, chromaticity, coma – mostly look quite good. But, as expected, from the sharpness point of view the open aperture is not its forte. On the other hand, F2.8 is good for portraits, F4 looks amazing for anything and F5.6 is ready for landscapes with modern digital requirements – very nice result.

Let’s go further: it has two strong advantages, namely a huge front element and a huge rear element. Just look at the bubbles on 3 meters focusing distance – truly “Hollywood-like” portraiture view. The result is something like one from the bokeh-monster – legendary Rokkor 58mm f1.2 but multiplied by two, which is in terms of focal length, which is in terms of fastness.

I need to underline my feelings of this lens: it is not champion because of IQ (just look at MD 100mm 1:2.5 – that is the resolution bomb for 100mm distances), but if to sum its IQ with its aberrations – then we get unique art-tool. It requires skills from photographers because needs the hiding of disadvantages, but in good hands (or just a luck) it will give a few masterpieces.

The lens is very hard to find, and the copies that are sold are insanely expensive due to the collector’s price – I didn’t see exclusions on popular auctions for a many years. Therefore, I can’t say that it is worth buying for everyone, my opinion: this is a really good lens for those who know how to use old-school bokeh and lack of sharpness at open apertures, and it can also be recommended to everyone who is interested in not only IQ lens, but also its historical value.


3 Comments

Darrell Owens · 2022-08-13 at 01:41

Great read and thanks for the mention!

Marko · 2023-10-24 at 18:22

Is there any other source of this lens being radioactive?

Thanks

Marko

    Tony · 2023-10-24 at 19:05

    I have no answer.. wasn’t interested because I can’t imagine a more authoritative source than Han Fiasco or any of the other people mentioned above

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