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old Pentax Ultra Achromatic 4.5/85mm beats the A* 1.4/85mm
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PostPosted: Tue Mar 02, 2010 9:50 pm    Post subject: old Pentax Ultra Achromatic 4.5/85mm beats the A* 1.4/85mm Reply with quote
Just found an interesting optical analysis about the Pentax A* 1.4/85mm and the old Ultra Achromatic Takumar 4.5/85mm showing that the old wise lens beat the new one hands down... Wink Wink

(C) pentaxstudy.jp

The spot diagram clearly shows how well color corrected the UA 85mm is and how well a spot stays a spot at various wavelengths.

I made a shootout once against the 1.8/85mm and also there it excelled. (and yes spot I do have a second one....but it is way to sharp for portraits)

Last edited by kds315* on Sun Aug 14, 2016 8:43 am; edited 3 times in total


PostPosted: Tue Mar 02, 2010 9:55 pm    Post subject: Reply with quote
I have to spare some money and find one Razz But I remember that in an other test you did, the UA Tak was no so sharp as the other tested lenses ?


PostPosted: Tue Mar 02, 2010 10:05 pm    Post subject: Reply with quote
You mean that test:
http://photographyoftheinvisibleworld.blogspot.com/2009/08/test-pentax-smc-f1885mm-vs-ultra.html
where the UA Tak 85mm looses against the SMC 1.8/85mm - no wonder, as it was not designed for that.
But at medium and close distances, it is clear winner, considering that it also does UV and IR in the same quality!
Amazing what they designed so many years ago.... Exclamation Exclamation


PostPosted: Wed Mar 03, 2010 10:48 am    Post subject: Reply with quote
kds315* wrote:

Amazing what they designed so many years ago.... Exclamation Exclamation


Maybe it is not a fair comparison, given the moderate maximum aperture and the huge price tag of the UA Tak, both when new and now. But still it's very nice to see this - I should use my 85/4.5 more often.


PostPosted: Wed Mar 03, 2010 11:21 am    Post subject: Reply with quote
Klaus, thanks for posting this!

I wonder if I should add the 85/4.5 to my collection. However, I find the price hard to justify because it probably will not be used much. It's good to know that it is in good hands! Cool


PostPosted: Wed Mar 03, 2010 11:35 am    Post subject: Reply with quote
This UA 85mm is a very exotic lens and hardly anyone will use its full potential anyway. I was just amazed to see what excellent results the japanese designers have achieved 40 years ago using CaF2 + Quartz lenses (long before Fluoride lenses were used in normal lenses)


PostPosted: Wed Mar 03, 2010 11:57 am    Post subject: Reply with quote
I don't do UV photography yet, but I already do sometimes infrared, so it should be better with a UA tak Very Happy


PostPosted: Wed Mar 03, 2010 12:08 pm    Post subject: Reply with quote
Klaus,

BTW, in the spot diagram, would the results vary with different apertures? As I interpret the results shown here, they are taken at various wavelengths at various locations from the centre of the image circle - right?

Peter,

If you'd like to try out the UATak you're welcome to, I'm living a full 10 km away from you in Wageningen.


PostPosted: Wed Mar 03, 2010 1:07 pm    Post subject: Reply with quote
dickb wrote:
Klaus,

BTW, in the spot diagram, would the results vary with different apertures? As I interpret the results shown here, they are taken at various wavelengths at various locations from the centre of the image circle - right?

Peter,

If you'd like to try out the UATak you're welcome to, I'm living a full 10 km away from you in Wageningen.


That's a very generous offer Dick! Surely Peter would also make this lens "sing"!!

Dick: the spot diagram will certainly change if the lens is stepped down, since the outer rays will be cut off. Not sure if diffraction effects are included in that raytracing program. You read it correctly though.

If that interest you, I would advise to pay http://pentaxstudy.bufsiz.jp/ a visit and have a look in their "Lens Design Room"


PostPosted: Wed Mar 03, 2010 1:17 pm    Post subject: Reply with quote
Thank you Klaus for posting these interesting results concerning a little known lens.

kds315* wrote:
I was just amazed to see what excellent results the japanese designers have achieved 40 years ago using CaF2 + Quartz lenses (long before Fluoride lenses were used in normal lenses)

According to Gerjan van Oosten, the Ultra-Achromatic Takumar 85mm F/4.5 appeared in 1968. My Canon FL-F 300/5.6, the world's first "normal" telephoto with a fluorite element, dates back from 1969, which is not so long after the UA Takumar release!

Cheers!

Abbazz


PostPosted: Wed Mar 03, 2010 1:36 pm    Post subject: Reply with quote
Engineers learn fast Sebastien!! Kidding aside - I think this was about the time when artificially grown CaF2
crystals became available in affordable prices. Fused silica ("quartz") was there much earlier, but also the method
to work with this very brittle CaF2 had to be developed first.


PostPosted: Wed Mar 03, 2010 2:25 pm    Post subject: Reply with quote
dickb wrote:

Peter,

If you'd like to try out the UATak you're welcome to, I'm living a full 10 km away from you in Wageningen.


Dick,

Now that's a generous offer indeed! By the way, I have moved a full 100kms away, but I still work 10kms from Wageningen.

Do I have any lens in my collection that you would like to try out? Let's continue in PM's because it's getting offtopic now.


PostPosted: Wed Mar 03, 2010 4:51 pm    Post subject: Reply with quote
kds315* wrote:


Dick: the spot diagram will certainly change if the lens is stepped down, since the outer rays will be cut off. Not sure if diffraction effects are included in that raytracing program. You read it correctly though.


Do you know at what aperture the results presented in this spot diagram are taken, wide open or at a standardized aperture, f.i. f/5.6?


PostPosted: Thu Mar 04, 2010 11:28 am    Post subject: Reply with quote
Ok, it's beat the A* 85...but f/4.5 what an ugly aperture Evil or Very Mad


PostPosted: Wed Aug 10, 2016 7:26 pm    Post subject: Reply with quote
How it looks like in its red velvet lined box...



PostPosted: Wed Aug 10, 2016 11:29 pm    Post subject: Reply with quote
Fascinating test from an equally fascinating lens, Klaus.

Would you suspect that in addition to the new materials and the new materials processing techniques you describe, that these lenses were also made in relatively small numbers, with much handwork, and much attention to detail? These could hardly be described as consumer products, I assume they were produced for a speciality market with very exacting specifications and tight tolerances. I would further assume they were sold at a premium price which could justify a level of precision beyond the ordinary.

I am not an expert in wave optics, but I would surmise that the truly surprising quality of this lens, which is designed for optimum performance at close/medium range within the IR and UV parts of the spectrum, might be that if performs as well as it does in the visible part of the electro-magnetic spectrum.

Do you agree?

P.


PostPosted: Thu Aug 11, 2016 5:17 am    Post subject: Reply with quote
pdccameras wrote:
Fascinating test from an equally fascinating lens, Klaus.

Would you suspect that in addition to the new materials and the new materials processing techniques you describe, that these lenses were also made in relatively small numbers, with much handwork, and much attention to detail? These could hardly be described as consumer products, I assume they were produced for a speciality market with very exacting specifications and tight tolerances. I would further assume they were sold at a premium price which could justify a level of precision beyond the ordinary.

I am not an expert in wave optics, but I would surmise that the truly surprising quality of this lens, which is designed for optimum performance at close/medium range within the IR and UV parts of the spectrum, might be that if performs as well as it does in the visible part of the electro-magnetic spectrum.

Do you agree?

P.


I fully agree! Today only some 30 lenses or thereabouts are known to still exist and are highly sought after by PENTAX collectors but also scientists / biologists and people wishing to perform reflected UV photography (like me).

It has never been cheap, when it was sold in 1972, its price new was $1.400, which based on the inflation calculator would be in 2015 some $7.000. Of course used lenses can be had cheaper than that today, with some luck, if they ever show up.

Used lenses still are in usually very good shape with well working mechanics and optics, so either they were not used often, were treated well with respect or simply very well made with tight tolerances. I think it was a combination of all of the above. And certainly I woudl also assume they were made in very small batches of lenses, all by hand. The used synthetic fluorite crystals (only synthetic quartz and synthetic fluorite crystals were used to make this lens, no optical glass) are extremely brittle and prone to break, so also this called for careful hand assembly and individual adjustment.

In 2009 I made a simple test of comparison, far away from any scientific test: http://photographyoftheinvisibleworld.blogspot.de/2009/08/test-pentax-smc-f1885mm-vs-ultra.html

My friend Marco Cavina has written 2006 about it here (in Italian language): http://www.scattineltempo.it/Download/SNT%20aprile2006.pdf and here about multispectral lenses: http://www.marcocavina.com/articoli_fotografici/articolo_obiettivi_uv.pdf


PostPosted: Thu Aug 11, 2016 9:37 pm    Post subject: Reply with quote
A lens of tremendous historical value. Congratulations, Klaus!

Interestingly Pentax has never been a big name in optics for scientific purposes as Nikon and Olympus in Japan, or Leitz and Zeiss in Germany.


PostPosted: Fri Aug 12, 2016 5:26 am    Post subject: Reply with quote
Gerald wrote:
A lens of tremendous historical value. Congratulations, Klaus!

Interestingly Pentax has never been a big name in optics for scientific purposes as Nikon and Olympus in Japan, or Leitz and Zeiss in Germany.


Well, it actually has. In 1968 (!!!) when this lens was started to be sold (after the not so successful Quartz Takumar 85mm, which was uncorrected and very difficult to use - I have it, too), it was the only chromatically corrected lens in the world commercially available for the 35mm (24x36mm) format. All the others came later, Nikon with their UV-Nikkor 105mm in 1984/85, 17 years later. Zeiss developed for NASA their UV-Sonnar 105mm and sold it from 1968 onwards, but for Hasselblad's 6x6 format Wink

Here a comparison: top: Zeiss UV-Sonnar 105mm, middle: UA Takumar 85mm, bottom: UV-Sonnar 105mm:


Engineers always like to "learn" from each other ... Wink


PostPosted: Sat Aug 13, 2016 10:55 pm    Post subject: Reply with quote
Let me try to explain my reasoning. Microscopy has always been one of the most important branches of scientific optical instruments. Leitz and Zeiss were already famous manufacturers of microscopes, long before they started to manufacture cameras and photographic lenses. In Japan, the first Nikon microscope was manufactured in the early 1900s and Olympus launched its first microscope in 1920. Much of the development of photographic lenses was due to research in optics for microscopes. Already in 1904 Zeiss introduced the first commercial UV microscope. The use of fluorite and quartz crystals in microscope objectives was a reality 100 years ago.

As far as I know Asahi Pentax never made a microscope so the company's background in scientific optical instrumentation was not comparable to Leitz, Zeiss, Nikon and Olympus. Hence my curiosity to know what motivated Pentax to launch a photographic UV lens in 1968. By the way, it seems that Nikon released a UV lens in 1965, the 55mm f / 4.0-32 UV-Nikkor Auto.

Certainly I was not trying to diminish the value of the Pentax Ultra Achromatic lens, which was indeed a Pentax breakthrough over the other manufacturers of scientific optics. Brilliant Pentax!


PostPosted: Sun Aug 14, 2016 8:19 am    Post subject: Reply with quote
Gerald wrote:
Let me try to explain my reasoning. Microscopy has always been one of the most important branches of scientific optical instruments. Leitz and Zeiss were already famous manufacturers of microscopes, long before they started to manufacture cameras and photographic lenses. In Japan, the first Nikon microscope was manufactured in the early 1900s and Olympus launched its first microscope in 1920. Much of the development of photographic lenses was due to research in optics for microscopes. Already in 1904 Zeiss introduced the first commercial UV microscope. The use of fluorite and quartz crystals in microscope objectives was a reality 100 years ago.

As far as I know Asahi Pentax never made a microscope so the company's background in scientific optical instrumentation was not comparable to Leitz, Zeiss, Nikon and Olympus. Hence my curiosity to know what motivated Pentax to launch a photographic UV lens in 1968. By the way, it seems that Nikon released a UV lens in 1965, the 55mm f / 4.0-32 UV-Nikkor Auto.

Certainly I was not trying to diminish the value of the Pentax Ultra Achromatic lens, which was indeed a Pentax breakthrough over the other manufacturers of scientific optics. Brilliant Pentax!


Yes, I know all that. Quartz and Fluorite were used them, but natural grown crystals, Quartz namely from the large deposits in Brazil - you should like that Smile

About the UV-Nikkor 55mm, this was NOT a chromatically corrected lens, but a simple quartz triplet similar to the Quartz Takumar 85mm. Both disappeared quickly, as its use was very complicated to get sharp UV images due to the massive focus shift.

This wasn't about lenses for UV, it s about a very early CHROMATICALLY CORRECTED LENS FOR PHOTOGRAPHY and SIMILAR lenses were mentioned made by others.

There are many lenses for UV, uncorrected, you find them nearly all at my site http://macrolenses.de/objektive_sl.php?lang in the Special Lens section Wink


PostPosted: Sun Aug 14, 2016 1:18 pm    Post subject: Reply with quote
kds315* wrote:

This wasn't about lenses for UV, it s about a very early CHROMATICALLY CORRECTED LENS FOR PHOTOGRAPHY


I think you've missed my point. My question was not about highly corrected lenses for UV and visible light, but why Pentax made this type of lens in 1968, not Zeiss, Leitz, Nikon or Olympus. As I said before, Pentax had virtually no tradition in optics for scientific instrumentation.

About the chromatic correction itself, Canon claims that it started mass production of fluorite in 1968, which means that synthetic fluorite should already be available in small scale many years before. Designing a chromatically corrected lens for visible and UV light is not conceptually difficult if the optical designer has available the proper crystals. I don't think Pentax, or any other manufacturer had difficulty in the late 1960s in finding fluorite and quartz in size and quality needed to make a well corrected lens for UV and visible light. The problem in manufacturing such type of lens was cost, which greatly restricted the market for it. I have the impression that the Ultra Achromatic lens was used by Pentax primarily as a technological showcase. At that time, Pentax cameras were widely used in macro photography and on microscopes in universities and research centers, so Pentax perhaps wanted to impress the scientific community with a special lens like the Ultra Achromatic.

P.S.: Your website about macro lenses is very interesting and brings a lot of useful information for those interested in this type of photography. Highly recommended.


PostPosted: Sun Aug 14, 2016 4:25 pm    Post subject: Reply with quote
Gerald wrote:
kds315* wrote:

This wasn't about lenses for UV, it s about a very early CHROMATICALLY CORRECTED LENS FOR PHOTOGRAPHY


I think you've missed my point. My question was not about highly corrected lenses for UV and visible light, but why Pentax made this type of lens in 1968, not Zeiss, Leitz, Nikon or Olympus. As I said before, Pentax had virtually no tradition in optics for scientific instrumentation.

About the chromatic correction itself, Canon claims that it started mass production of fluorite in 1968, which means that synthetic fluorite should already be available in small scale many years before. Designing a chromatically corrected lens for visible and UV light is not conceptually difficult if the optical designer has available the proper crystals. I don't think Pentax, or any other manufacturer had difficulty in the late 1960s in finding fluorite and quartz in size and quality needed to make a well corrected lens for UV and visible light. The problem in manufacturing such type of lens was cost, which greatly restricted the market for it. I have the impression that the Ultra Achromatic lens was used by Pentax primarily as a technological showcase. At that time, Pentax cameras were widely used in macro photography and on microscopes in universities and research centers, so Pentax perhaps wanted to impress the scientific community with a special lens like the Ultra Achromatic.

P.S.: Your website about macro lenses is very interesting and brings a lot of useful information for those interested in this type of photography. Highly recommended.


I disagree, I don't think Pentax made it as a showcase. They made the Quartz Takumar 85mm before and even before that in 1962 made a rarely known LF Quartz Takumar 135mm lens! That one was used by the Swedish police for Forensic Photography, which proves that Pentax had a long standing history to also design and built very special lenses for scientific purposes.

Inscription on box (translation thanks to Michio Akiyama):

Japanese
--------
Shigaisen-yoh-Suisyo-Renzu
Asahi-Kogaku-Kogyo-Kabushiki-Gaisya
Syowa 37 Nen 10 Gatsu Sei

English
-------
Crystal Lens for Ultraviolet Rays
Asahi Optical Industry Company
Manufactured in October, 1962





http://macrolenses.de/ml_detail_sl.php?ObjektiveNr=305
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