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Nikon 105mm f/4.5 UV-Rayfact

Lens
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#1 Andrea B.

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Posted 25 December 2020 - 21:19

Last Update: 22 Mar 2021 JMC transmittance charts from Post #16 added to Post #1.
Note: Additional information or links about this lens are welcomed and will be incorporated into the first post as time permits.


Nikon 105mm f/4.5 UV-Rayfact

Manufacturer: Nikon Corporation, Tokyo, Japan
Sakura Electronics Industry began manufacturing Nikkor lenses in 1963 under the direction of Nikon Corporation. In 1973 their name was changed to Tochigi Nikon. In 2001 the Rayfact brand was established. As of April 2020 the manufacture of Rayfact products was transferred back to Nikon Corporation. I think the Rayfact 105/4.5 began to be manufactured in 2005, but I have not been able to confirm that. This lens is a copy of the old UV-Nikkor 105/4.5 for which manufacture stopped in 1999.
Lens Label: Nikon Rayfact PF10545MF-UV
Note: Although not so labeled, this lens is commonly referred to as the UV-Rayfact.
Currently Manufactured: Yes

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.
Attached Image: RayfactChart.jpg

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.
Attached Image: JMC_UVNikkor_Rayfact_1.jpg

Preceding chart with expanded Y-axis
Attached Image: JMC_UVNikkor_Rayfact_2.jpg




Photos of the UV-Rayfact 105/4.5
These UV-Rayfact images are also courtesy of UVP member JMC.
Attached Image: rayfact1.jpg
Attached Image: rayfact2.jpg
Attached Image: rayfact3.jpg
Attached Image: rayfact4.jpg
Andrea G. Blum
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#2 Andrea B.

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Posted 25 December 2020 - 21:55

Who would like to take over this entry and add some sample photos from their UV-Rayfact??
And some photos of the UV-Rayfact??
Andrea G. Blum
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#3 Andy Perrin

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Posted 25 December 2020 - 22:01

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

#4 JMC

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Posted 26 December 2020 - 11:32

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.
Jonathan M. Crowther

http://jmcscientificconsulting.com

#5 SteveE

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Posted 26 December 2020 - 17:36

There are a number of Rayfract lenses on eBay.
I am assuming that not all Rayfracts are UV capable
Is this correct?
- Steve

#6 nfoto

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Posted 26 December 2020 - 20:34

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

#7 DaveO

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Posted 26 December 2020 - 23:11

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

#8 UlfW

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Posted 27 December 2020 - 09:17

View PostJMC, on 26 December 2020 - 11:32, said:

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.
Ulf Wilhelmson
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#9 JMC

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Posted 14 January 2021 - 10:04

Example images taken with the Rayfact 105mm UV lens.

Yooperlite mineral fluorescence under different UV wavelengths - https://www.ultravio...dpost__p__38512

Senecio jacobaea [Common Rawort] using UV reflection - https://www.ultravio...dpost__p__37459

Goldfinch feather in UV, visible and IR - https://www.ultravio...dpost__p__29298

An array of flowers under 302nm light with different UV filters - https://www.ultravio...dpost__p__27395

Blow torch flame at different wavelengths - https://www.ultravio...dpost__p__26841

Normal and cross polarised UVA and UVB images of a flower and pollen - https://www.ultravio...dpost__p__26168
Jonathan M. Crowther

http://jmcscientificconsulting.com

#10 Andrea B.

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Posted 14 January 2021 - 20:33

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

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Posted 15 January 2021 - 12:03

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 ...
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#12 Andrea B.

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Posted 15 January 2021 - 19:35

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.
Andrea G. Blum
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#13 Andy Perrin

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Posted 15 January 2021 - 20:38

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!

#14 Andrea B.

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Posted 15 January 2021 - 21:44

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.
Andrea G. Blum
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#15 StephanN

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Posted 16 January 2021 - 11:27

View PostAndrea B., on 15 January 2021 - 21:44, said:

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 :wink:
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#16 JMC

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Posted 16 January 2021 - 15:32

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......

Attached Image: Rayfact vs UV Nikkor full scale.jpg

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

Attached Image: Rayfact vs UV Nikkor magnified.jpg

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.

Edited by JMC, 16 January 2021 - 15:33.

Jonathan M. Crowther

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#17 nfoto

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Posted 16 January 2021 - 19:55

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.

#18 Andrea B.

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Posted 17 January 2021 - 00:02

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.
Andrea G. Blum
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#19 colinbm

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Posted 17 January 2021 - 07:02

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....."

#20 dabateman

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Posted 17 January 2021 - 09:33

View Postcolinbm, on 17 January 2021 - 07:02, said:

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.