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UltravioletPhotography

Kuri 35mm vs. Noflexar 35mm


Andy Perrin

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All this innuendo about a particular lens & who started it & the people who carry on with it is all a bit sad. Has anybody ever established who made the first construction & exactly who copied who, or it just might have been a collective thing of mutual support ? But it is all irrelevant, if you have a good lens for a particular purpose them go out & enjoy it. You don't need to sit here & denigrate it or the people who fix & refurbish them.
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I still don't have an answer to my question: "do these "Kuri Clones" perform like a real one?" - irrespective of what you want to call them.

 

Bernard, you are driving yourself to buy a spectroscope, just like I did.... :lol:

"how long is a piece of string..."

Like all lenses there are good ones & bad ones, just like apples in a cart......

The best one is the one in your hand, go out & use it.

I have lenses here that could be good but aren't, I just need to find someone good to clean & polish the glass & hope they come back better ?

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Bernard, you are driving yourself to buy a spectroscope, just like I did....

 

 

It's more cost-effective if someone else buys the spectroscope and gives you the answer! Out of interest, what spectroscope did you buy, and what sort of cost?

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Gulp! That price takes it out of the gadget/toy caytegory!

 

I started out trying to make rainbows with prisms & photographing the wavelengths & found out about diffraction gratings.... the rest is history....

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dabateman

Bernard the problem is my igoriginal 35mm, which is great, will not equal your igoriginal 35mm lens.

So if you want to know the answer, you would need to compare for yourself with your lens to what you want to compare with using your method of comparing lenses to know what you want.

Just set up an Ebay alert for kuribayashi and hope for a cheap one. All the recent have been ridiculous high. I didn't see the one Andy bought as I have a 35mm and don't need a second.

 

For me now the lens must either autofocus in UV. If it fails that than it must see into UVC. That is helpful at reducing my lens purchases.

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You cannot be sure that a lens is good even if it is an original Kuribayashi or Kyoei Acall, with known deep UV reach.

There are both production variations and wear from usage and handling.

 

These lenses were never expensive, high end designs and it is quite likely some difference between individual lenses.

From what I can see in my 105mm Kuri and my 135mm Kyoei, the mechanical design is reasonably ambitious, but we know nothing about how much effort was put into the optical quality and alignment, for that group of lenses.

When those lenses were built there probably were a bigger quality variation as they were more hand built than modern lenses are.

 

As Andy has showed in this thread, his good looking Kuri was less sharp than his Noflexar.

I think the only thing the Kuri was better at, was the already confirmed UV-reach.

 

All the positive opinions about Kuri Kyoei and sometimes their "clones" we see are just opinions.

There are rather few real detailed evaluations beside for UV-reach.

 

I am not saying that those lenses are bad, just that their reputation is a bit inflated just as their prices.

 

The prices of the Noflexar 35mm are also quite inflated.

This is the highest I ever have seen for that lens:

https://www.ebay.com...OgAAOSw~xRgS3ai

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Bernard the problem is my igoriginal 35mm, which is great, will not equal your igoriginal 35mm lens.

 

Is it great on a full frame camera or are you evaluating the center square on your 3/4-sensor? :wink:

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dabateman
Only on a 43rds sensor. First tested on 10Mpixel E510, then 16Mpixel Em5mk2/ EM1MK1. I should do a proper test with my Pen-f, its 20Mpixels and most strict. It too has an Olympus leaky UV/IR blocking filter and can see at least 380nm. Haven't tested its full reach yet.
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It's more cost-effective if someone else buys the spectroscope and gives you the answer! Out of interest, what spectroscope did you buy, and what sort of cost?

The UV reach of those lenses are already very well documented by several different methods. No need to buy a spectrometer.

 

Even if Col's advanced light analyser is expensive, it is not the best tool for analysing transmission characteristics through filters and lenses.

The device is a very good specialised tool for analysing the spectral power content of light sources like lamps and LEDs.

It would be perfect for setting up illumination sources in sensitive locations like museums where you want the artefacts displayed in the very best way without any aging.

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Andrea B.

Bernard: I find it unfortunate that there is a lot of bias against IgorOriginal on UVP with no basis in fact that I can see.

 

I don't think that is true. And remember, Igor *is* a member here. He is not currently active but has always been welcome. (Vendor-members have a lot of restrictions in order that UVP can remain non-monetized and also avoid liability insurance costs.)

 

Insofar as I have a "job" here on UVP -- aside from software and editing chores -- that job is to try to enable the gathering and storage of as much factual information about reflected UV photography (and other Vis/IR/Fluor types) as possible. Am I a bit of a purist about this? Of course I am -- because that is what I am *supposed* to be doing for you, the members.

 

In light of that declaration, I must add that I think it is misleading to advertise on Ebay any non-Kuribayashi lens as a Kuribayashi "clone". I'm not even sure what that means, "clone".(*) Those igoriginal lenses would sell just as well without that.

 

(*)...and yes, we have had that "clone" discussion before! Let's not repeat it. :smile:


 

Ulf mentions above: "optical quality and alignment".

 

While we are trying to provide some really excellent, properly measured data about lens transmittance, I must add that nobody here has an actual optical bench, at least that I know of. So we will always lack complete, verifiable, repeatable data about the quality and alignment of any lens. We can make and have made pretty good assessments using informal tests or charts, but there will always be some variablilty and error in such informal assessments.


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Andy Perrin

Andrea, going back to my particular Kuri:

 

1) I don’t know why you think the brightness difference is due to exposure differences— both photos had the same exposure and same settings and same editing and same white balance. I was careful about not jiggling that aperture ring by accident. The Kuri photo is brighter because it has a wider bandpass than the Noflexar. We know this from spectroscopy and my results are consistent with that.

 

2) As determined with the NEX-7, the center of the lens is incapable of infinity focus on the M42-NEX adapter. It focuses fine on a helicoid. It’s unquestionably an issue with this particular lens.

——

 

Re optical benches: they aren’t magic, you know. Even if someone had one, we would still be capable of getting an erroneous result. All equipment is only as good as the user, and honestly I trust Ulf’s spectroscopy knowledge on his own equipment to within the kinds of tolerances we need to make decisions about buying lenses.

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Just set up an Ebay alert for kuribayashi and hope for a cheap one.

 

 

The problem I have is why should I bother? I haven't seen any info. to indicate that there is any benefit of a real Kuri over an Igororiginal (or a Soligor/Prinz/Hanimex 35mm) - that's all I'm asking for. Perhaps that information doesn't exist - in which case the general rubbishing of the Igororiginal is not (yet) justified.

 

I've got no axe to grind over the IgorOriginal. I have a pair of them, but my go-to lens at 35mm is the Soligor enlarger lens (which is half-frame only). I'm just trying to understand why the Kuri is seen as the maestro of 35mm while the Igororiginal is portrayed as a shifty, second-rate wannabe. Perhaps that is the case, but I'd love to see some data to back it up.

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The UV reach of those lenses are already very well documented by several different methods. No need to buy a spectrometer.

 

 

I've seen your data on a couple of Soligors and a Prinz 35mm, which are all very similar. But I can't see anything on the Kuri 35 or Igororiginals - have I missed something?

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Andy Perrin
Is there even such a thing as an “IgOriginal” as a lens with a fixed set of parts? I thought he just put together whatever bits he has lying around.
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Andrea B.

Andy: Is there even such a thing as an “IgOriginal” as a lens with a fixed set of parts? I thought he just put together whatever bits he has lying around.

 

Well, Andy, the point is, we just don't really know. Nothing wrong with cobbling together parts if the result is reasonably sharp and reasonably aberration free. That is tricky though. Properly aligning a lens element can be quite difficult.


 

Bernard: But I can't see anything on the Kuri 35.

 

There is nothing formal here on UVP. For Ulf to measure this lens, he either has to buy it himself or someone has to send him one.

 

However, data from previous tests (JMC) (Dr. Klaus) and Sparticle tests (Cadmium) indicate reach below 320 nm.

310 I think?

Added Later: Dr. Klaus' charts show the Kuri reaching 320 nm.

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But I can't see anything on the Kuri 35.

 

There is nothing formal here. For Ulf to measure this lens, he either has to buy it himself or someone has to send him one.

However, data from previous tests (Dr. Klaus) and Sparticle tests (Cadmium) indicate reach below 320 nm.

310 I think?

That is exactly what I ment.

Those informal tests do not give any numerical data but gives a good hint about the reach.

I have no intention of buying a Kuri 35mm, as it for me is a waste of money. I very seldom need a 35mm lens for UV and already have a Noflexar 35mm.

The Kuri-type of lens is not very useable for my typical closeup-motifs.

 

If anyone want to send me a Kuri I will naturally measure it and then return it to the sender.

I would expect it to measure rather similar to the Soligor KA as I believe that lens is very close in optical design.

 

I am quite open to measuring other lenses too, but then after prior agreement.

If sent from within the EU there would not be any delays due to customs handling.

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Andrea B.

Andy: I don’t know why you think the brightness difference is due to exposure differences

 

Thanks for seeing my questions, Andy. We got sidetracked in this topic.

 

I wasn't really thinking about width of bandpass. I was thinking about T-stops versus F-stops when comparing lenses. I do understand that was not your particular purpose in the test photos above. But it would have also been interesting to see what adjustment it takes in exposure time to get the Novo to match the brightness of the Kuri.

 

Sampling JPGs is not recommended, but it was curious that the white-balanced false-colors of the two lenses were only 2° apart on the color wheel. Maybe the Novo doesn't reach as far as the Kuri, but apparently it reaches far enough for the yellows to be the same but for differing saturations.


 

Andy: Re optical benches: they aren’t magic, you know.

 

No, of course they aren't. And I personally do not think MTF charts tell the entire story, but neither should we discount them. Everything in balance.

 

One does need an optical bench to more precisely check for aberrations, decentering, sharpness and FFD of a lens.

 

I have often wanted to BEG Roger Cicala to run a couple of my UV lenses on Olaf to see just how "good" they actually are compared to the usual hype. :grin:


 

Here is a nice write-up about how to do a brick wall test.

Selecting the Proper Brick Wall for Photographic Tests

 

By Roger Cicala

 


 

This next link is also a cool article. Andy's Kuri seems to have a slightly off FFD. But I was truly surprised at the variation in tested camera body FFDs for some of the brands as shown in this link. A bit scarey.

The Great Flange-to-Sensor Distance Article. Part II: Photo Cameras

 

By Roger Cicala

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Andy Perrin
Since I do everything based on the histogram in the live view, it doesn’t make much difference to me? Should it be?
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Andrea B.

http://photographyoftheinvisibleworld.blogspot.com/2012/07/kuribayashi-f3535mm-lens-for-reflected.html

 

At that link you can see a Kuri 35/3.5 vs some Soligor 35/3.5

and a Kuri 35/3.5 vs a Prinzgalaxy 35/3.5 (that is the one-word version not the two-word Prinz Galaxy).

 

Just a link. I'm not advocating anything here by providing links.

The Kuri 35/3.5 on those pages seems not to reach quite as far as 310 nm.

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The phrase 'Kuri clone' is nebulous.

That isn't the point of this topic though.

I think the point of this topic is to compare the Kuri and Noflexar sharpness, and possibly UV transmission depth.

Well done Andy.

Andrea, you have both lenses, so it would be great if you could do the same test for sharpness.

 

My the way, here are a couple good links on these types of lenses from Enrico.

http://www.savazzi.net/photography/35kyoei.html

http://www.savazzi.net/photography/35mmuv.html

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Andy Perrin
I think I will redo the tests next week (I’m away from my camera equipment at the moment) due to my discovery that the Kuri wasn’t focused properly.
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