Nikon 105mm f/4.5 UV-Rayfact (and its older twin, the Nikon 105/4.5 UV-Nikkor)

[Andrea B.]

Last Update: 14 June 2022 Cleaned up timeline and added reference links.

24 June 2022 Added info about another label.

 

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Nikon 105mm f/4.5 UV-Rayfact

This lens is an exact copy of the Nikon 105/4.5 UV-Nikkor, which is no longer manufactured.

 

Manufacturer: Nikon Corporation, Tokyo, Japan

1963 Sakura Electronics Industry began manufacturing Nikkor lenses under the direction of Nikon Corporation.

1973 Sakura Electronics became Tochigi Nikon.

1984 Nikon announced the Nikon 105mm f/4.5 UV-Micro-Nikkor designed by Mr. Koichi Wakamiya.

1985 Sept. The lens was marketed as the Nikon 105mm f/4.5 UV-Nikkor.

1999 The UV-Nikkor was discontinued.

2001 The Rayfact brand of industrial lenses was established at Tochigi Nikon.

2005 Nov 18. The Nikon Rayfact PF10545MF-UV 105mm f/4.5 began limited production at Tochigi Nikon.

2020 April. The Rayfact industrial lens business was transferred back to Nikon Corporation's Digital Solutions Business Unit.

Reference Links:  LINK LINK LINK LINK LINK

 

Lens Labels

Nikon Rayfact PF10545MF-UV Serial# (2012 - current)

UV 105mm 1:4.5 Serial# (~ 2006 - 2012)*

UV-Nikkor 105mm 1:4.5 Serial# (1984-1999)

 

*Dates supplied by Mr. Michio Akiyama (owner of the Nikon Lens Society’s website at redbook.jp) in correspondence with UVP member Doppelganger9000.

 

Currently Manufactured: Yes

 

Lens Designer: Mr. Koichi Wakamiya of Nikon Corp.

Lens Type: manual focus with focus lock screw, prime, medium telephoto, close-up/10.8in

Lens Design: 6 elements in 6 groups.

Three elements are fused silica (quartz) and three are calcium fluoride.

Focal Length: 105 mm

Aperture Range: f/4.5 - f/32

 

Focus Shift: Corrected between UV and Visible.

Minor IR adjustment needed using the small red IR dot on the distance ring.

 

Format Coverage: full frame, image size = 43.6 mm

Working Distance: 273.9mm/10.8in - ∞

Magnification:

Macro: Use an extension tube such as the Nikon PN-11 to attain a close working distance of 2".

 

Mount: Nikon F

Helicoid: Yes

Flange Focal Distance (FFD): 46.5 mm

The lens can easily be used on any camera with an FFD shorter than 46.5 mm by means of a mount adapter.

Front Filter: 52 mm x 0.75 mm

 

Sharpness: While we do not have any MTF charts for the UV-Rayfact to support subjective observations, this lens is said by its users to be exceptionally sharp just like its older twin, the UV-Nikkor 105/4.5.

 

Transmittance Summary

The UV-Rayfact transmits 70-80% between 220 - 900 nm.

Infrared transmittance goes beyond 900 nm, but is not shown in the following charts.

 

Transmittance Charts

This was the manufacturer's transmittance chart from their design specs. It is included here to provide some information beyond 400 nm. The actual manufactured lens transmittance (next two charts) is flatter across the UV and visible spectrum.

 

Our UVP member Jonathan Crowther (JMC) of JMC Scientific Consulting has provided two charts showing that the UV-Rayfact and the old UV-Nikkor have the same transmittance.

 

Preceding chart with expanded Y-axis

 

 

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Photos of the UV-Rayfact 105/4.5

These UV-Rayfact images are also courtesy of UVP member JMC.

[Andrea B.]

Who would like to take over this entry and add some sample photos from their UV-Rayfact??

And some photos of the UV-Rayfact??

[Andy Perrin]

Will someone please give me one? I will gladly test it!

[JMC]

Andrea,

The image in Set #2 here was taken with a Rayfact 105mm - https://www.ultravioletphotography.com/content/index.php/topic/2956-ranunculus-acris-common-buttercup-more-examples/page__view__findpost__p__23494

 

With regards to the anti-reflective coatings, is it that it has none, or that the ones it has are not the same as normally used for visible light imaging? The Company7 page for the lens says it has a "lack of conventional antireflective coatings". That doesn't say to me that it has no coatings, just not conventional ones. I will admit, I don't know either way, but would be surprised if there was nothing on there coatings wise.

 

Have you got the full page PDF spec sheet from them (with the ambient illumination ratio and distortion graphs)? If not I can share a copy. I think according to the wording on that sheet the spectral transmission data is based on the design values, and not actual measurements on the lens, at least that's how I read it.

[SteveE]

There are a number of Rayfract lenses on eBay.

I am assuming that not all Rayfracts are UV capable

Is this correct?

[nfoto]

Yes. Rayfact is a brand label, not a specific lens (design).

[DaveO]

All my images taken after 23 February 2014 were taken with the Rayfact PF10545, before that I was using a quartz 105 mm lens. I started out with a Pentax K5 then moved to a Nikon D750 which I still use.

 

Dave

[ulf]

Andrea,

The image in Set #2 here was taken with a Rayfact 105mm - https://www.ultravio...dpost__p__23494

 

With regards to the anti-reflective coatings, is it that it has none, or that the ones it has are not the same as normally used for visible light imaging? The Company7 page for the lens says it has a "lack of conventional antireflective coatings". That doesn't say to me that it has no coatings, just not conventional ones. I will admit, I don't know either way, but would be surprised if there was nothing on there coatings wise.

 

Have you got the full page PDF spec sheet from them (with the ambient illumination ratio and distortion graphs)? If not I can share a copy. I think according to the wording on that sheet the spectral transmission data is based on the design values, and not actual measurements on the lens, at least that's how I read it.

With twelve lens surfaces a very rough estimation of the refractive index to 1.5, normal incidence and ignoring all secondary reflections you get an estimative transmission of 83%

That is in the neighbourhood of what the graph shows.

It might be true that this lens lack coatings.

[JMC]

Example images taken with the Rayfact 105mm UV lens.

 

Yooperlite mineral fluorescence under different UV wavelengths - https://www.ultravioletphotography.com/content/index.php/topic/4087-yooperlites-specimen-uvf/page__view__findpost__p__38512

 

Senecio jacobaea [Common Rawort] using UV reflection - https://www.ultravioletphotography.com/content/index.php/topic/4008-senecio-jacobaea-common-ragwort-more-examples/page__view__findpost__p__37459

 

Goldfinch feather in UV, visible and IR - https://www.ultravioletphotography.com/content/index.php/topic/3437-goldfinch-feather-in-uv-visible-and-ir/page__view__findpost__p__29298

 

An array of flowers under 302nm light with different UV filters - https://www.ultravioletphotography.com/content/index.php/topic/3265-4-x-filter-tests-with-uvp-302nm-light-source-and-flowers/page__view__findpost__p__27395

 

Blow torch flame at different wavelengths - https://www.ultravioletphotography.com/content/index.php/topic/3221-ir-visible-and-uv-of-small-blow-torch-flame/page__view__findpost__p__26841

 

Normal and cross polarised UVA and UVB images of a flower and pollen - https://www.ultravioletphotography.com/content/index.php/topic/3170-uva-and-uvb-polariser-moxtek-uvd260a/page__view__findpost__p__26168

[Andrea B.]

Jonathan, thank you for the links. I will incorporate some of your and Dave's photos into the main text as time permits.

[StephanN]

Would it make sense, now that the lens-data part is starting to really grow, to add some sort of pricing-info? I'm aware that this is sensitive info, as not everybody wants to declare on the internet: Hey, guys, look, I've got a lens worth 10000 USD at home, why don't you drop by, break in and steal it. Also, prices change, but what about something along the lines of "If you look for the EL-Nikkor 80mm f/5.6 on the internet, expect to pay between 100 and 200 USD" ? This kind of info is already present in many threads after all ...

[Andrea B.]

The problem has been that once a lens becomes known as UV-capable then its price starts to go up.

So we usually don't discuss prices much.

[Andy Perrin]

Yean, StephanN, look what happened to the Noflexar price if you want a case-study in supply and demand. Let's not make all our lives worse!

[Andrea B.]

Prices of these UV-capable lenses do vary up and down over the years. Sometimes if you are patient you will see prices drop. Then a lens becomes popular and prices climb again.

 

There are times when I thought .... well, geez, looks like I've made some money on that UV lens .... only to see the price drop back down to where I purchased it. (Making money on a UV lens not my goal, of course. I'm just speaking figuratively.) And of course the opposite is true -- I have, in retrospect, overpaid for a UV lens only to see its price drop.

 

I've seen the Ebay prices of the original, rather rare Nikon Noct-Nikkor 58/1.2 vary as much as $2000 over the years. (I snagged one years ago for a decent enough price from a forum friend.)

 

Kuribayashi 35/3.5 prices skyrocketed for awhile, but I managed to get one for a very reasonable price this year. Not where the prices started out, of course, but no where near the highest prices that we saw for a while.

[StephanN]

Prices of these UV-capable lenses do vary up and down over the years. Sometimes if you are patient you will see prices drop. Then a lens becomes popular and prices climb again.

 

OK, that's true, the basic lens data don't change at all, but the price may vary a lot. So, it would be too much of a hassle to keep the prices up to date.

 

Still, don't quite see how putting a price in a thread which praises a lens for its UV-capability will help to increase the price? Surely the praise itself may achive this, regardless of whether there's a price listed or not, right? But I'm not really into economy and the psychology which drives it, so I'd better shut up about this

[JMC]

Yeah, I wont be posting up prices of my lenses. If nothing else my wife might read the forum......

 

Ok. A head to head transmission measurement through the Rayfact 105mm f4.5 UV and the UV Nikkor 105mm f4.5, between 280nm and 420nm. Each scan is an average of 10 runs, 1s each, and boxcar width of 2. Drum roll......

 

 

They are essentially identical to one another, even if you blow up the y axis;

 

 

My measurements are slightly lower than the Rayfact datasheet, but as we already mentioned, that is probably a theoretical chart rather than a measured curve.

 

So no new coatings, no major changes, they are the same in terms of transmission.

[nfoto]

They even look the same, apart from a difference in the lens label.

 

 

A free hint: your wife probably knows more than she is letting on.

[Andrea B.]

Jonathan, thank you for the terrific charts !!!! And it is good to have proof that the UV-Rayfact and UV-Nikon are also clones w.r.t. transmittance in addition to construction and appearance.

[colinbm]

Ha Ha Jonathan, a joke on similar lines....

"I hope, when I die, that my wife doesn't sell the boat for what I told her I paid for it....."

[dabateman]

Ha Ha Jonathan, a joke on similar lines....

"I hope, when I die, that my wife doesn't sell the boat for what I told her I paid for it....."

No, boats are different. You can buy one for really cheap. Its the $100000 needed after to make it work the way you want.

[Andrea B.]

Update 22 Mar 2021: Added transmittance charts to first post.

[nfoto]

I take it we treat the original UV-Nikkor and the Rayfact UV-105 jointly in this thread? For all intents and purposes they are the same lens.

 

My guess is that possessions by UVP members represent a sizeable fraction of the UV lenses produced.I have two of them and believe not the only one stocking up on the UV-Nikkors.

[nfoto]

A characteristic property of the UV-Nikkor/Rayfact is the focusing collar goes way "beyond" the infinity mark, and the red IR dot is on the opposite side, i.e. to the right, instead of the usual left-hand side position of nearly all other lenses.

 

 

The UV-Nikkor is also a simple lens to "chip" (CPU-enable). Which is a very useful feature when you do experimental UV work and need to ascertain exposure data. However this will only work with the lens mounted on F- or Z-system cameras.

[dabateman]

Your copy is AIS as it has the groove near the pin lock and an orange 32. I think I saw some might be before AIS.

[nfoto]

The UV-Nikkor was released years after Nikon had introduced the AiS aperture operation on their lenses.