NikonGear

Gear Talk => Lens Talk => Topic started by: Akira on July 04, 2019, 14:49:12

Title: Possible emulation of CRT Nikkor?
Post by: Akira on July 04, 2019, 14:49:12
Mr. Akiyama, the owner of the famous "Red Book Nikkor" website, revised the sections dedicated to Nikkor-O 55/1.2 a.k.a. CRT Nikkor.  He added a couple of images of the prototype of the CRT Nikkor called "Nikkor-O Auto 50mm f/1.2-1.4" displayed during the special exhibition of rare prototypes of Nikkor lenses held at the Nikon Museum in Shinagawa, Tokyo (scroll way down):

https://redbook-jp.com/redbook-e/record2/crt.html

What interests me is the description for the lens pictured in the second image from the bottom of the linked webpage:

https://redbook-jp.com/redbook/record2/f260.jpg

Interestingly, the cross section of the CRT Nikkor sans the front element resembles very closely to that of the ubiquitous Nikkor Auto 50mm f/1.4:

https://redbook-jp.com/redbook/record2/f320.jpg

https://imaging.nikon.com/history/story/0044/index.htm

Then I wonder if you could emulate the CRT Nikkor using 50/1.4 lens with a closeup attachment of an appropriate diopter?
Title: Re: Possible emulation of CRT Nikkor?
Post by: Michael Erlewine on July 04, 2019, 14:52:23
If you figure out how to do that, be sure to let me know. LOL. Getting that kind of clarity would be tough, IMO.

Try out the new Voigtlander APO-Lanthar Macros for Sony E-Mount, the 65mm and 110mm.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 04, 2019, 14:55:33
If you figure out how to do that, be sure to let me know. LOL. Getting that kind of clarity would be tough, IMO.

Try out the new Voigtlander APO-Lanthar Macros for Sony E-Mount, the 65mm and 110mm.

MIchael, an achromatic (2 elements glued together) closeup diopter might better the image quality to some extent.   ;)

Your images have already proved the amazing performance of the new Apo-Lanthars!
Title: Re: Possible emulation of CRT Nikkor?
Post by: Michael Erlewine on July 04, 2019, 14:57:43
MIchael, an achromatic (2 elements glued together) closeup diopter might better the image quality to some extent.   ;)

Your images have already proved the amazing performance of the new Apo-Lanthars!

Well,, try it out and tell me how to do it.  As you know, like yourself, I love the Nikkor "O" lens and look for ways to extend its usefulness.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 04, 2019, 15:23:36
Well,, try it out and tell me how to do it.  As you know, like yourself, I love the Nikkor "O" lens and look for ways to extend its usefulness.

I will whenever I get the chance.  And, yes, I love Niikor O.  I've moved through cameras of different brands, but CRT has always been adapted to all of them!
Title: Re: Possible emulation of CRT Nikkor?
Post by: Michael Erlewine on July 04, 2019, 15:26:45
I will whenever I get the chance.  And, yes, I love Niikor O.  I've moved through cameras of different brands, but CRT has always been adapted to all of them!

Putting it on the Z7 with Leica (M39) thread adapter and some extension gives you more total range for the lens.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Birna Rørslett on July 04, 2019, 16:08:04
"A little more" range ... too far away from its designated 1:4 to 1:5 magnification (approx.) makes all parts of the image frame except the very centre go to mush.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Michael Erlewine on July 04, 2019, 16:20:56
"A little more" range ... too far away from its designated 1:4 to 1:5 magnification (approx.) makes all parts of the image frame except the very centre go to mush.

True, but don't go THAT far and it still works well, IMO.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Bruno Schroder on July 04, 2019, 18:12:24
Is this the config you have in mind, Akira?
Title: Re: Possible emulation of CRT Nikkor?
Post by: Roland Vink on July 04, 2019, 22:47:38
Interestingly, the cross section of the CRT Nikkor sans the front element resembles very closely to that of the ubiquitous Nikkor Auto 50mm f/1.4 [...]
Very interesting, I think you are right! The prototype lens does look very similar to the regular production Nikkor-S 50/1.4, and the information card even states "... a normal lens that incorporates a convex lens at the front in order to photograph close-up images ..."
Probably the closest way to replicate the CRT Nikkor is to add one of the close-up diopters such as No.0, 1 or 2. I wonder if the acrhromat No.3 or No.4 would give improved image quality?

In those days designing a lens was very expensive and time-consuming, most ray-tracing calculations were done by hand, or with very primitive computers, so it was easier to modify an existing design rather than build a new lens from scratch. For example the early 200mm Medical Nikkors are based on the regular Nikkor-Q 200/4 lens, and in tale 70, it shows how the Nikkor-H 300/4.5 is just a refinement of the Nikkor-P 300/4.5.

Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 05, 2019, 00:53:38
"A little more" range ... too far away from its designated 1:4 to 1:5 magnification (approx.) makes all parts of the image frame except the very centre go to mush.

You could be right, Birna.  That said, the enigmatic 50/1.4 lens, apparently based on Ais 50/1.4, I sold you might be corrected for the close range by putting the front and the rear groups a little further from each other than the original Ais.  So, that could be a good candidate for the experiment.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 05, 2019, 01:01:49
Is this the config you have in mind, Akira?

Bruno, yes, exactly!
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 05, 2019, 01:09:16
Very interesting, I think you are right! The prototype lens does look very similar to the regular production Nikkor-S 50/1.4, and the information card even states "... a normal lens that incorporates a convex lens at the front in order to photograph close-up images ..."
Probably the closest way to replicate the CRT Nikkor is to add one of the close-up diopters such as No.0, 1 or 2. I wonder if the acrhromat No.3 or No.4 would give improved image quality?

In those days designing a lens was very expensive and time-consuming, most ray-tracing calculations were done by hand, or with very primitive computers, so it was easier to modify an existing design rather than build a new lens from scratch. For example the early 200mm Medical Nikkors are based on the regular Nikkor-Q 200/4 lens, and in tale 70, it shows how the Nikkor-H 300/4.5 is just a refinement of the Nikkor-P 300/4.5.

I agree, Roland.  I also guess the LF Nikkors like 105/5.6 and 135/5.6 share the same optical design with the EL equivalents.

Just like the CRC of Ais Micro Nikkor 55/2.8, you could manipulate the targeted magnification by adjusting the distance between the front and the rear groups.  So, sharing the LF lens designed for infinity and the EL lens designed for larger magnification factors should be possible with the near-symmetric Gaussian design.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Dr Klaus Schmitt on July 05, 2019, 09:00:59
Very interesting find Akira!

You might know that there are at least other emanations of this same lens made by different manufaturers? I was happy to find them years ago... (pic (c) Wiki Commons)

Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 05, 2019, 11:05:43
Very interesting find Akira!

You might know that there are at least other emanations of this same lens made by different manufaturers? I was happy to find them years ago... (pic (c) Wiki Commons)

Klaus, yes, I do know and have seen other CRT lenses of similar specification like the one made by Kowa.  I know about the JML but cannot identify the one on the left of the image you shared.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Bruno Schroder on July 05, 2019, 14:23:37
Bruno, yes, exactly!
I did some quick handheld test shots on the DF (this sample of the 50/1.4 is not AI converted) with a 3T and a 4T and the results are quite good, particularly with the 4T. I'll do a direct comparison with the CRT on the D500 hopefully if I can find my other sample, which has been AI milled.

This has to wait till Monday however, the weekend being fully busy with friends and family.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 06, 2019, 04:15:21
Thank you, Bruno!  I'm looking forward to seeing your results, but please take your time.  No hurries!
Title: Re: Possible emulation of CRT Nikkor?
Post by: Michael Erlewine on July 06, 2019, 20:03:56
Let me get this right. Take a Nikon 50mm f/1.4 lens and put a Nikon #4 close-up lens on it and take photos, correct?

I tried this and here is what I got.
Title: Re: Possible emulation of CRT Nikkor?
Post by: JJChan on July 07, 2019, 13:39:19
I don't have a Nikkor-S 50mm but I used 4T with the Noct - these straight out of D850 resized only with no processing
Title: Re: Possible emulation of CRT Nikkor?
Post by: Roland Vink on July 07, 2019, 23:07:19
Let me get this right. Take a Nikon 50mm f/1.4 lens and put a Nikon #4 close-up lens on it and take photos, correct?
To be precise: A pre-AI Nikkor-S 50/1.4 Auto, probably with serial 465011 and higher.  Earlier 50/1.4 lenses made between 1962 and 1966 had a slightly different optical design. In the mid 1960s the optics were revised with slightly different curvature and spacing, probably different glass materials too. The CRT Nikkor was made in the early 1970s so would have been based on the later version.

Also, the #4 close-up lens is a 2-element lens, to more closely replicate the CRT Nikkor you would need to use one of the single element close-up lenses #1, #2 or #3.

Actually, there is one thing which does not stack up. If you add a close-up lens, the focal length of the becomes shorter than the master lens alone (and the speed is correspondingly increased). The focal length of the CRT is 55mm, while the Nikkor-S 50/1.4 has a focal length of just 51.6mm - adding a close-up lens would shorten it to something like 45mm.

Maybe when the CRT Nikkor was designed, maybe Nikon used the optics of the Nikkor-S 50/1.4 but first scaled them up before adding the close-up lens??  Maybe someone who has both lenses can compare the size of the rear elements of both lenses.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Michael Erlewine on July 07, 2019, 23:36:33
To be precise: A pre-AI Nikkor-S 50/1.4 Auto, probably with serial 465011 and higher.  Earlier 50/1.4 lenses made between 1962 and 1966 had a slightly different optical design. In the mid 1960s the optics were revised with slightly different curvature and spacing, probably different glass materials too. The CRT Nikkor was made in the early 1970s so would have been based on the later version.

Also, the #4 close-up lens is a 2-element lens, to more closely replicate the CRT Nikkor you would need to use one of the single element close-up lenses #1, #2 or #3.

Actually, there is one thing which does not stack up. If you add a close-up lens, the focal length of the becomes shorter than the master lens alone (and the speed is correspondingly increased). The focal length of the CRT is 55mm, while the Nikkor-S 50/1.4 has a focal length of just 51.6mm - adding a close-up lens would shorten it to something like 45mm.

Maybe when the CRT Nikkor was designed, maybe Nikon used the optics of the Nikkor-S 50/1.4 but first scaled them up before adding the close-up lens??  Maybe someone who has both lenses can compare the size of the rear elements of both lenses.

I have a 50mm/1/4 with serial # 410167

I have a recent 50mm/1/4

I have an earlier NOCT

For this experiment what would the range of serial numbers be for the 50mm you folks are discusssing.  Between 465011 and ??

I am just curious.

Is this the type of lens and within range:

https://www.ebay.com/itm/Near-Mint-Nikon-NIKKOR-S-Auto-50mm-F1-4-Lens-Japan-Kovaku-Nippon-Beautiful/133098245647?hash=item1efd460e0f:g:UDMAAOSw5ipdFxOG


Here is one that says it is converted. Let me know if this is still the correct type and I might just get it to experiment.
https://www.ebay.com/itm/EXC-5-Nikon-Ai-Converted-Nikkor-S-Auto-50mm-f-1-4-MF-Prime-Lens-from-JAPAN/392305831819?hash=item5b573fef8b:g:CBEAAOSwj61cswyS


Would any of the 55mm Nikkors work for this of which there are many?
Title: Re: Possible emulation of CRT Nikkor?
Post by: Roland Vink on July 08, 2019, 01:24:14
The CRT Nikkor came out in the early 1970s, so if it was based on the Nikkor-S 50/1.4 it would have been based on the then-current optical design. This is the time-line of the original Nikkor-S 50/1.4 (see http://photosynthesis.co.nz/nikon/lenses.html#50fast):
Your lens no.410167 would be from the original series - I assume it is the old metal hill-and-dale focus ring (if you missed a digit from the serial number then no.410xxxxx would correspond to the AI 50/1.4 which has a different optical design). All the lenses above are pre-AI so would need modification for use on a D850, but are fine on the Z cameras.

We can probably get a close approximation of the CRT Nikkor by adding a close-up lens to the 2nd Nikkor-S 50/1.4. I'd suggest the single-element No.0, 1 or 2 (in increasing strength) as the best candidates. Be aware there is probably more to it than that. The 50/1.4 optics would have been scaled up to something like 60mm with the extra convex front element bringing the entire focal length back to 55mm. The curvature, spacing, glass materials and coatings of individual elements may be been changed to optimise the lens for its intended purpose. The extra element added at the front also won't be the same as any of the screw-in close-up lenses that Nikon made for general photography. Given that it's always going to be an approximation, it probably does not matter which of your standard lenses you use - try out various combinations and see what works.

Note that none of the 50mm Nikkors (with the possible exception of the Noct) are anything like the highly corrected APO lenses that you usually work with. If you do want to explore this area further, I'd consider a multicoated Nikkor-S.C or the "New Nikkor" as they will give better colours and contrast, unless you prefer the more muted rendition. The "New Nikkor" also has a greater focus range and may be better optimised at close range, but that is just a guess - some lens / close-up lens combinations work better than others.

It's also worth mentioning that single-element close-up lenses are by definition uncorrected for spherical aberrations (I haven't come across any aspherical close-up lenses!) Most 50/1.4 Nikkors are a little over-corrected, so adding a close-up lens this should make the background bokeh smoother.

Title: Re: Possible emulation of CRT Nikkor?
Post by: Michael Erlewine on July 08, 2019, 02:30:10
Roland Vink: You are indeed a treasure!

I bought one of the New versions SN 2936443 converted

Thanks so much. I have all the close-up set, so I will play around with it.

Thanks so much for clarifying this.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 08, 2019, 04:08:34
Let me get this right. Take a Nikon 50mm f/1.4 lens and put a Nikon #4 close-up lens on it and take photos, correct?

I tried this and here is what I got.

Michael, thank you for taking time for the clumsy experiment.  At least on my screen, your combo appears to live quite well up to the task.  The achromatic element of #4 may help here.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 08, 2019, 04:10:10
I don't have a Nikkor-S 50mm but I used 4T with the Noct - these straight out of D850 resized only with no processing

JJ, thank you for chiming in.  The rendition of the combo looks lovely.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 08, 2019, 04:12:35
Roland, thank you for the further analysis of what is happening optically.  Indeed, the focal length is one of the remaining enigmas.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Michael Erlewine on July 08, 2019, 07:16:20
Roland, thank you for the further analysis of what is happening optically.  Indeed, the focal length is one of the remaining enigmas.

I would imagine the focal length depends on the use of the lens, which is to monitor CRT screens. That focal distance must have something to do with it.  I am constantly trying all kinds of extension to all kinds of lenses to see if I can get the particular kind of range I would like, knowing that  in some cases it works well enough and in others it destroys the quality of the lens.. To me, the curvature of the the CRT screen gives the lens that odd (psychedelic) like aspect.  I would think that Birna or Erik might know how this was put together. I can only experiment.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Bruno Schroder on July 08, 2019, 19:05:19
Maybe when the CRT Nikkor was designed, maybe Nikon used the optics of the Nikkor-S 50/1.4 but first scaled them up before adding the close-up lens??  Maybe someone who has both lenses can compare the size of the rear elements of both lenses.

measuring the lens element itself is not easy. The caliper is very sharp and I don't want to scratch the lens. My measure of the inner brass diameter around the rear element of the CRT is 36.45mm but the lens is chamfered and the element itself appears to be 34.3mm. The 50/1.4 S Auto nr 794265 has a light baffle of 36.5mm and the rear element itself is 34.1mm. My 2nd sample, the 50/1.4 S Auto nr 1187713, has a light baffle of 36.2mm and the rear element is also 34.1mm.

Roland, is 0.2mm the difference you would expect between the CRT and the 50/1.4 or is it within the margins of the measurement error?

Now, I only need to retrieve the 0, 1 and 2 close up lenses. When I got the 3T and 4T I thought I would never use them anymore, stored them somewhere and forgot about them. I don't have the faintest idea of where they are …. That said, I would always trust Michael's test over mine :)

Anyone else measuring either the CRT or the 50/1.4?
Title: Re: Possible emulation of CRT Nikkor?
Post by: Roland Vink on July 09, 2019, 03:59:28
I would imagine the focal length depends on the use of the lens, which is to monitor CRT screens. That focal distance must have something to do with it.  I am constantly trying all kinds of extension to all kinds of lenses to see if I can get the particular kind of range I would like, knowing that  in some cases it works well enough and in others it destroys the quality of the lens..
As you know, some lenses work well (optically) with extension, others are not so good. All will suffer to some degree when extended beyond the range for which they were designed. Field curvature, astigmatism and other aberrations are likely to become worse, especially away from the centre of the image.

In many cases, a better way to increase magnification is to use a close-up lens instead. The CRT lens seems to be a good example of this. The master lens can remain within it's optimum range, and if the close-up lens is well matched, the results can be very good. In special cases the closeup lens could even correct aberrations in the master lens resulting in improved performance. Some lenses work better with the close-up lens reversed. Generally the two-element close-up lenses work better since they are better corrected. But as always, there are no firm rules, you have to experiment with each lens/close-up combination and find what works best.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Roland Vink on July 09, 2019, 05:25:43
measuring the lens element itself is not easy. The caliper is very sharp and I don't want to scratch the lens. My measure of the inner brass diameter around the rear element of the CRT is 36.45mm but the lens is chamfered and the element itself appears to be 34.3mm. The 50/1.4 S Auto nr 794265 has a light baffle of 36.5mm and the rear element itself is 34.1mm. My 2nd sample, the 50/1.4 S Auto nr 1187713, has a light baffle of 36.2mm and the rear element is also 34.1mm.

Roland, is 0.2mm the difference you would expect between the CRT and the 50/1.4 or is it within the margins of the measurement error?
Nikkor-S 50/1.4 has a true focal length of 51.6mm. If the CRT Nikkor is a scaled up Nikkor-S 50/1.4, I would guess the focal length to be around 60mm (with the extra convex lens at the front bringing the total focal length to 55mm). My assumption was that the diameter of each lens element would be scaled up accordingly. However that may not be the case, so my earlier suggestion is probably not much help.

A good example is the Medical-Nikkor 200/5.6. The optics are borrowed from the Nikkor-Q and set into the barrel with a small amount of extension giving 1/15x magnification. The diameter of the elements was reduced (the 200/4 permanently stopped down to f/5.6), probably to give more room for the built-in ring-light and to improve performance for closeup photography.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Dr Klaus Schmitt on July 09, 2019, 15:44:34
Usings diopters is an old and very useful method, also often used with printing (printer) lenses, where I see dedicated diopters attached to them to adjust focal length.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 13, 2019, 03:50:17
My humble reminder of the original CRT (shot at f2.8 on APS-C).
Title: Re: Possible emulation of CRT Nikkor?
Post by: Dr Klaus Schmitt on July 13, 2019, 11:29:59
Beautiful Akira!!
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 13, 2019, 13:28:22
Beautiful Akira!!

Thank you, Klaus!
Title: Re: Possible emulation of CRT Nikkor?
Post by: dickb on July 14, 2019, 00:23:01
Klaus, yes, I do know and have seen other CRT lenses of similar specification like the one made by Kowa.  I know about the JML but cannot identify the one on the left of the image you shared.

Are you sure about the Kowa lens? Most of those seem to be intended for tandem use like the TV/XR Heligons. The one on the left is an FJW industries 54mm f/1.2. I just got my hands on one, to see if it is indeed designed to the same specs as my beloved Nikkor-O 55/1.2. At first glance it is at least very similar, taken with a Sony A7 and at f/1.4 I think, first the FJW:
Title: Re: Possible emulation of CRT Nikkor?
Post by: dickb on July 14, 2019, 00:25:35
And the Nikkor-O:
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 14, 2019, 00:45:35
Are you sure about the Kowa lens? Most of those seem to be intended for tandem use like the TV/XR Heligons. The one on the left is an FJW industries 54mm f/1.2. I just got my hands on one, to see if it is indeed designed to the same specs as my beloved Nikkor-O 55/1.2. At first glance it is at least very similar, taken with a Sony A7 and at f/1.4 I think, first the FJW:

I couldn't identify the one on the left.  Thank you for the identification and the sample image.

I don't think the CRT lenses are designed to be used in combination with another optics because they are designed to shoot the oscilloscope screen directly.
Title: Re: Possible emulation of CRT Nikkor?
Post by: dickb on July 14, 2019, 11:50:17
Indeed, CRT lenses aren't designed to be used in tandem. I am just unaware of any Kowa 55 1.2 CRT lens. Could you point me to one? Thanks.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 14, 2019, 12:40:50
Indeed, CRT lenses aren't designed to be used in tandem. I am just unaware of any Kowa 55 1.2 CRT lens. Could you point me to one? Thanks.

I thought you identified the lens depicted on the left in the image Klaus posted.  Isn't that a Kowa one?
Title: Re: Possible emulation of CRT Nikkor?
Post by: dickb on July 14, 2019, 14:46:03
I identified it as an FJW Industries 54mm f/1.2.  I know of no Kowa connection to that lens. You were asserting you "have seen CRT lenses of similar specification like the one made by Kowa". So I was wondering if you could point me to info on that Kowa CRT lens.

On a related note, I came across some information on the use of the Nikkor-O 55/1.2 and JML ESDS 56/1.2, on a dpreview forum posted by someone under the name mynakedsoda:

The lens is the JML Optical 56mm f/1.2. First some history on this lens. During the 1960's and 70's the US Atomic Energy Commision contracted with EG&G Energy Measurements to build special purpose cameras to record the faint traces on that would appear on CRT screens during atomic tests. The first cameras used Nikkor 50mm 1.4 rangefinder lenses while later cameras used the more application appropriate Nikkor-O 55mm 1.2. The final cameras produced by EG&G used the JML Optical 56mm 1.2. It appears that JML was hired to produce this lens because the Nikkor-O was no longer available. I have personally never seen nor held the Nikkor-O but was informed by the previous owner of this lens that the similiarities between the two (he has owned mulitple copies of both) are striking and it is obvious that JML had the Nikkor in mind when producing this replacement. He even went on to inform me that while he could see little difference in the final sharpness both could achieve, he felt the JML reached peak sharpness sooner (f5.6) than the Nikkor (f8) and ehxibited slightly less CA at wide open to approximately f4. I have no way to confirm this myself but if it is even the equal of the Nikkor then I consider myself most fortunate considering the opinion that experts such as Bjorn Rorslett have of this lens, "The 55 f/1.2 CRT Nikkor is very very sharp at f/1.2 and amazing at f/1.4, at least my sample starts to delcine at f/8 and even more at f/11. It must be one of the all-time best performers ever made by Nikon." High praise indeed from the man that's used literally hundreds of Nikkors if not more!

My guess is that both JML and FJW designed a replacement for the Nikkor-O 55/1.2. The JML version (56/1.2 ESDS 109) appears to be the one actually used, I don't know if the FJW 54/1.2 ESD 109 was. Mine was new old stock, still wrapped in paper, and it doesn't have a serial number, the large box marked S/N is completely blank. 
Title: Re: Possible emulation of CRT Nikkor?
Post by: Dr Klaus Schmitt on July 14, 2019, 15:05:40
Great you found it Dick, indeed it is the FJW lens left in that picture!! Did not have the time to dig it out...
Title: Re: Possible emulation of CRT Nikkor?
Post by: Dr Klaus Schmitt on July 14, 2019, 15:10:50
Btw. the "father" of that lens most likely was this one (which was used for Los Alamos experiments then...). Note the very unusual thread mount...

(http://www.macrolenses.de/bilder/NI50_IMG_5134_wp_b.jpg)

(http://www.macrolenses.de/bilder/NI50_IMG_5135_wp_b.jpg)

(http://www.macrolenses.de/bilder/NI50_IMG_5137_wp_b.jpg)
Title: Re: Possible emulation of CRT Nikkor?
Post by: Michael Erlewine on July 14, 2019, 15:23:17
I have a different version of this type of lens. It is a JML OPTICAL 56MM F/1.2 lens with an electronic shutter that I have wide open. It has an extension that attaches with three Allen wrenches that is labelled "RAFCAMERA 065 - M42x1. I have not done much with it yet..
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 14, 2019, 15:32:48
I identified it as an FJW Industries 54mm f/1.2.  I know of no Kowa connection to that lens. You were asserting you "have seen CRT lenses of similar specification like the one made by Kowa". So I was wondering if you could point me to info on that Kowa CRT lens.

I did see a Kowa 55/1.2 lens at a second-hand shop called Lemon-Sha in Ginza, Tokyo.  Unfortunately, it was a bit too expensive to grab it.  If my memory serves, it looked rather similar to the Nikkor-O than the one on the left in the image Klaus posted.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 14, 2019, 15:34:48
Btw. the "father" of that lens most likely was this one (which was used for Los Alamos experiments then...). Note the very unusual thread mount...

Thank you, Klaus.  That could be the same optics as the normal Nikkor-S 50/1.4 with the distance between the front and the rear groups adjusted for closer focusing range.
Title: Re: Possible emulation of CRT Nikkor?
Post by: dickb on July 14, 2019, 16:03:26
I have a different version of this type of lens. It is a JML OPTICAL 56MM F/1.2 lens with an electronic shutter that I have wide open. It has an extension that attaches with three Allen wrenches that is labelled "RAFCAMERA 065 - M42x1. I have not done much with it yet..

From what I have seen of these (not firsthand though) the JML 56/1.2 in electronic shutter and the JML 56/1.2 ESDS 109 in M39 appear to be not the same lens design. Can you tell the difference between the Nikkor-O and your JML, with regards to front and rear lens size and curvature, and perhaps distance between the front and rear element? On the Nikkor-O and the FJW these are nearly identical, with the Nikkor having a marginally longer barrel but more recessed elements, making the distance between front and rear element for both about 50mm.

BTW, nice for you that it came with a matching adapter from Rafael / RafCamera. Perhaps in your lens collection there are other lenses with a 65mm diameter you can adapt with it. Quick testing here shows that the Rodagon Heligon 100/1.6 has part of its barrel in 65mm diameter, as does the Qioptiq XR Heligon 100/1.5 you once got from me. The latter only if you can remove its 80mm diameter heavy aluminium outer barrel though (this is attached with a 72mm thread that is fixed with some sort of loctite, so it is a bit of a challenge).
Title: Re: Possible emulation of CRT Nikkor?
Post by: dickb on July 14, 2019, 16:11:30
I did see a Kowa 55/1.2 lens at a second-hand shop called Lemon-Sha in Ginza, Tokyo.  Unfortunately, it was a bit too expensive to grab it.  If my memory serves, it looked rather similar to the Nikkor-O than the one on the left in the image Klaus posted.

Interesting. I was only familiar with the Kowa 55mm in f/1.0 and f/1.1 version, both of which appeared to be designed for tandem use. Nice, more lenses to hunt down (not that I need more lenses actually).
Title: Re: Possible emulation of CRT Nikkor?
Post by: Michael Erlewine on July 14, 2019, 17:10:41
I have a different version of this type of lens. It is a JML OPTICAL 56MM F/1.2 lens with an electronic shutter that I have wide open. It has an extension that attaches with three Allen wrenches that is labelled "RAFCAMERA 065 - M42x1. I have not done much with it yet..

Two example shots for the JML 56mm f/1.2
Title: Re: Possible emulation of CRT Nikkor?
Post by: dickb on July 14, 2019, 17:56:51
Btw. the "father" of that lens most likely was this one (which was used for Los Alamos experiments then...). Note the very unusual thread mount..

Unusual for a Nikkor-S, or is the thread different from the Leica Thread Mount we see on the Nikkor-O?
Title: Re: Possible emulation of CRT Nikkor?
Post by: dickb on July 14, 2019, 22:19:10
The FJW 54/1.2 is indeed very similar to the Nikkor-O  55/1.2, both are a lot of fun used handheld on my Sony A7. Here is one wide open
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 15, 2019, 10:37:30
Another shot with Nikkor-O.  I realized I had never stopped down the lens to f8.0, but Michael's image posted to another thread inspired me to try.

A lily about to bloom.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Dr Klaus Schmitt on July 16, 2019, 08:13:37
very nice also at f8 Akira!
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 16, 2019, 08:40:40
very nice also at f8 Akira!

Thank you again, Klaus!
Title: Re: Possible emulation of CRT Nikkor?
Post by: Macro_Cosmos on July 17, 2019, 12:07:58
Very interesting find Akira!

You might know that there are at least other emanations of this same lens made by different manufaturers? I was happy to find them years ago... (pic (c) Wiki Commons)
There's about 3 Chinese copies of the lens at weird FLs such as 54 and 56 too, with presumably the same output.
Some old Chinese lenses are really good, there's copies of the UMN series with IQ that's indistinguishable to my eyes. Those are hard to come by though.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Dr Klaus Schmitt on July 17, 2019, 14:02:25
There's about 3 Chinese copies of the lens at weird FLs such as 54 and 56 too, with presumably the same output.
Some old Chinese lenses are really good, there's copies of the UMN series with IQ that's indistinguishable to my eyes. Those are hard to come by though.

Interesting!! Would you please post pictures of those mentioned Chinese copies?
Title: Re: Possible emulation of CRT Nikkor?
Post by: Macro_Cosmos on July 17, 2019, 16:03:56
Interesting!! Would you please post pictures of those mentioned Chinese copies?
Sure thing if I ever come across any. I never saved those listings and they are now all gone.
Some are displayed here: http://forum.mflenses.com/show-off-your-rare-lens-t75018,start,325.html
I'm sure you've seen them since I saw some of your posts  ;)
Title: Re: Possible emulation of CRT Nikkor?
Post by: Dr Klaus Schmitt on July 17, 2019, 17:04:46
Sure thing if I ever come across any. I never saved those listings and they are now all gone.
Some are displayed here: http://forum.mflenses.com/show-off-your-rare-lens-t75018,start,325.html
I'm sure you've seen them since I saw some of your posts  ;)

yes, those I know  ;)
Title: Re: Possible emulation of CRT Nikkor?
Post by: Seapy on July 19, 2019, 10:13:31
I hope this isn't a silly question, is the Nikkor 'S' 50mm f/1.4 pre ai, optically the same as the Nikkor 50mm f/1.4 ai/ais?  And what about the D, although being AF, I guess that's completely different...

I have a choice of both the 'S' pre ai and the later ais, the early lens is much cheaper than the the later one... both are in very good condition.  I already have a Nikkor 'D' 50mm f/1.4 AF.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Bruno Schroder on July 19, 2019, 10:32:34
Hi Robert,

If you look at Roland’s web site, http://www.photosynthesis.co.nz/nikon/serialno.html, different versions of the same lens are separated by grey lines. Large if the change is significant, small with minor changes.

The versions you mention are different.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 19, 2019, 10:34:51
I hope this isn't a silly question, is the Nikkor 'S' 50mm f/1.4 pre ai, optically the same as the Nikkor 50mm f/1.4 ai/ais?  And what about the D, although being AF, I guess that's completely different...

I have a choice of both the 'S' pre ai and the later ais, the early lens is much cheaper than the the later one... both are in very good condition.  I already have a Nikkor 'D' 50mm f/1.4 AF.

So far as I'm aware, the optical formula (7 elements in 5 groups) of Nikkor S 50/1.4 remained the same until the "K" version.  The newer formula (7elements in 6 groups) remained the same from Ai to AF-D.  However, the glass material could have been changed over time, and the radius of the spherical surfaces could have been re-adjusted accordingly.

The current AF-S G employs yet another formula (8 elements in 7 groups).
Title: Re: Possible emulation of CRT Nikkor?
Post by: Roland Vink on July 19, 2019, 11:35:32
So far as I'm aware, the optical formula (7 elements in 5 groups) of Nikkor S 50/1.4 remained the same until the "K" version.
Correct. The thick dark line indicates a new optical design. Medium dark line represents a minor adjustment of the previous optic (change to glass material, curvature and/or spacing of lens elements). The medium light line is an upgraded barrel design with the same optics, and the hairline is a new serial number range.

The original 7-element 5-group Nikkor-S 50/1.4 has three variants:
- original Nikkor-S serial no 314111 - 454670.
- upgraded Nikkor-S from 465011 - 1613735. This includes the multicoated Nikkor-S.C version.
- Further upgrade for "New Nikkor" (K) 50/1.4 from 2797021 - 3004000, probably to improve performance at close range since it focuses closer.

After these lenses an all-new design was introduced with 7 elements in 6 groups, starting with the new K version (pre-AI), through AI, AI-S and AF versions.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 19, 2019, 12:00:27
Roland, thank you for straightening up the things!
Title: Re: Possible emulation of CRT Nikkor?
Post by: Seapy on July 19, 2019, 13:42:17
Thank you for your prompt replies, so it seems the lens needs to be from the 7-element 5-group Nikkor-S 50/1.4 variants, pre AI, probably not the 'K'.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Roland Vink on July 19, 2019, 21:44:56
Read my reply, no #21 in this thread :)
Title: Re: Possible emulation of CRT Nikkor?
Post by: Seapy on July 19, 2019, 23:21:01
Whoops! Sorry,  missed the detail there.  Great, will get something sorted, my source has a couple and also No. 1 and 2 closeup's.  I had a play last night with one but the other one is in his storage so I will try that asap.  I need his serial Numbers.
Title: Re: Possible emulation of CRT Nikkor?
Post by: Akira on July 20, 2019, 05:27:48
Well, you know, I guess I opened the can of worms... :o :o :o
Title: Re: Possible emulation of CRT Nikkor?
Post by: Seapy on July 20, 2019, 09:12:35
Thank you Akira, I like worms, they help fertilise the soil of projects and ideas.  ;D