Author Topic: Possible emulation of CRT Nikkor?  (Read 33676 times)

Toby

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Re: Possible emulation of CRT Nikkor?
« Reply #90 on: October 17, 2019, 07:45:32 »
To round out this discussion, a few shots with the Wollensak Oscillo-Raptar 75mm f1.9. There were three versions of Oscillo lenses in this focal length made by Wollensak. The first, the Oscillo-Anastigmat, seems not to be made with field curvature, and is more suitable for standard shooting. The second is the Oscillo-Raptar, made in two flavors 1:0.5 and 1:0.9 (they are quite similar in rendering). The third, the Oscillo-Amaton, also does not seem to have field curvature, but I do not have one and cannot confirm. All the Oscillo lenses I have make a giant jump in quality one stop closed, becoming much contrastier and losing glow around highlights.

Reversing this lens gives a lovely effect as well: check the last three shots here

Toby

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Re: Possible emulation of CRT Nikkor?
« Reply #91 on: October 17, 2019, 08:08:51 »
Beautiful images exemplifying characteristics of the special fast lenses, as always, Toby!

I don't disagree with you.  But I believe that the prototype was also designed with the specific amount of the field curvature in mind: the project had started specifically to record the CRT displays.

If that was the case, then either the "double gauss" body of the lens or the additional convex element at the front had to be designed with that field curvature. In either case, you will not get that adding a simple convex element to the front of a 50mm f1.4. I think it needs to be understood that almost all fast normal lenses of that period were some variant of double gauss, above f1.8 with an added element or elements to correct for CA. And of course specific curvatures of the elements varied in each design. The Nikkor 55mm 1.2, 55mm CRT and 50mm f1.4 share design similarities, with an extra rear element behind the usual convex element of a standard double gauss design. And it is true that the 55mm CRT adds another convex element at the front, unlike either of the standard lenses, but if you look at the thicknesses of the elements you will see major differences in formulation. The normal f1.2 has a front element that is much thinner  than the convex element just ahead of the front doublet in the CRT Nikkor. The 50mm f1.4 shares a thicker convex element in front of the front doublet with the CRT (which has a thinner convex element in front of that), but the design of the doublets is much more asymmetrical in the f1.4 than in the f1.2 standard or CRT lenses.

My point here is that all these lenses had specific designs intended to the purpose, and you will not get a CRT out of a standard lens (even if the front element is similar in both cases) because you are not taking into account the other five or six elements in the lens, which are specific to each design.

dickb

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Re: Possible emulation of CRT Nikkor?
« Reply #92 on: October 17, 2019, 16:49:54 »
The  FJW  lens arrived today. Am in the middle of several days of a video shoot, so I only had time to do a quickie, to see if the lens tracks well. It looks good and has potential for what I like to do. I had to cobble together an M39-M42 step-up ring to use as a stop ring for the adapter, but it worked.

Glad to hear it arrived safely. I had thought you would use the same adapters as you use for your Nikkor-O 55/1.2 lenses, given that they share the same layout.

Jack Dahlgren

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Re: Possible emulation of CRT Nikkor?
« Reply #93 on: October 18, 2019, 00:31:17 »
The JML is, I believe, a rebranded Ilex Oscillo Paragon 56mm f1.2. They look exactly the same. Much nicer, if you can find one, is the Oscillo Paragon 80mm f1.3, which easily fits into a M52 helicoid and has a more reasonable flange distance. At least I am speaking about the JML mounted in electronic shutter. I have no idea if the barrel version is the same. I doubt it, since the element sizes seem totally different.

I like your photos with the 80mm. I'm sure some will disagree, but the bokeh is rather painterly.

-Jack

Michael Erlewine

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Re: Possible emulation of CRT Nikkor?
« Reply #94 on: October 21, 2019, 15:39:20 »
Have finally had a little time for playing with the FJW lens. Indeed, it is fast and sharp. Here is just my first attempt using some Calla Lilies. THis is a stacked photo.

It amounts to a proof of concept for this lens. Yeah, it works fine.
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Erik Lund

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Re: Possible emulation of CRT Nikkor?
« Reply #95 on: October 21, 2019, 15:57:58 »
Lovely rendering, soft transitions and pleasing bokeh.
Erik Lund

Dr Klaus Schmitt

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Re: Possible emulation of CRT Nikkor?
« Reply #96 on: October 22, 2019, 01:18:49 »
Looks fine to me Michael! Congrats!
formerly known as kds315

Toby

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Re: Possible emulation of CRT Nikkor?
« Reply #97 on: October 23, 2019, 10:53:05 »
Very lovely photo!

Dr Klaus Schmitt

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Re: Possible emulation of CRT Nikkor?
« Reply #98 on: November 15, 2019, 15:48:52 »
Another one just showed up on ebay, TOBY here comes your chance!! ebay 143440880580
Dutch seller I know since years, reliable and good guy, met him....
(no relations to that sale btw.)
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Toby

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Re: Possible emulation of CRT Nikkor?
« Reply #99 on: November 15, 2019, 22:16:59 »
Thanks Klaus! But I think I'll just stay with my trust 55mm Nikkor-O. I'm starting to feel that too many of my lenses look like too many other of my lenses. I'm really a user, not a collector.