Rapid View Portrait (RVP) Pictorial lens

[evan clarke]

HaHa 8^)..

[russyoung]

Another RV lens with its original Morrocan red leather cap.

If you're interested in further reading, pages 122-127 of my dissertation discuss how the Rapid View & Portrait lens influenced the design of the Semi-Achromatic. No less an authority than Heinrich Kuhn, who owned both lenses, felt certain that Smith had copied the RVP design. I posit therein that another lens is the father of the Kodak Portrait lens, not the RVP.

YMMV.

Russ

[8x10 user]

I tried to buy one of these a few months ago and ended up getting scammed instead... This thread makes it hurt just that much more. Let me know if anyone sees one with the serial number of 17319.

Its definitely a very cool lens!

[Mark Sawyer]

If you're interested in further reading, pages 122-127 of my dissertation discuss how the Rapid View & Portrait lens influenced the design of the Semi-Achromatic. No less an authority than Heinrich Kuhn, who owned both lenses, felt certain that Smith had copied the RVP design. I posit therein that another lens is the father of the Kodak Portrait lens, not the RVP.

YMMV.

I had to go back and read those pages again, and now that your dissertation is out from the bookshelf, well, there goes the evening...

I'd offer that by the time of Smith's lens, the nature of the French Landscape Lens was so well known that no one predecessor could be pointed to. Smith's innovation of hand aspherizing the lenses for aspherical aberrations was what set his lenses apart from all others, and something that no one else (to my knowledge) has done before or since.

Similarly, I'd speculate the Kodak Portrait Lens owes the most to the Imagon, which (funky aperture disks not withstanding) seems much more similar in maximum aperture than the RVP. The Spencer Port-Land had a similar aperture, but had ceased production well before the KPL appeared, while the Imagon was in the midst of its long-running commercial success. From the more philistine point of view, "no bucks, no Buck Rogers".

We may never know, but half the fun is in the speculating...

[russyoung]

Just a reminder - the SemiAchromatic had no aspheric surfaces... P&S only made one lens, Visual Quality, with an aspheric surface and no Pictorialist of consequence used that lens... nonetheless Cooke modeled their modern PS945 after it.

[jumanji]

and no Pictorialist of consequence used that lens...

I'm curious why? Aspherical surface of Visual Quality make what difference(s) compared with Spherical surfaces of other soft focus lens?

[Mark Sawyer]

Just a reminder - the SemiAchromatic had no aspheric surfaces... P&S only made one lens, Visual Quality, with an aspheric surface and no Pictorialist of consequence used that lens... nonetheless Cooke modeled their modern PS945 after it.

I didn't know that, Russ. I've run across enough references to "hand ground" lenses (and similar terms) referring to pre-VQ P&S lenses to assume it was true. Here's one from Christies:

Beauty in the Details
In 1903, de Meyer began working with a special hand-ground lens made by Pinkham & Smith. Unlike a diffusion filter which blurs everything, the hand-ground lens softens and diffuses both shadow areas, and paradoxically maintains general image clarity while softening the hard edges. The effect is a luminous quality, a well-known attribute of the Pinkham & Smith lens, which suggests it was used to create this photograph.

(at: http://www.christies.com/features/20...er--224-1.aspx )

Alas, there's a lot of questionable information out there, and I hope I haven't added to it.

[Amedeus]

Just a reminder - the SemiAchromatic had no aspheric surfaces... P&S only made one lens, Visual Quality, with an aspheric surface and no Pictorialist of consequence used that lens... nonetheless Cooke modeled their modern PS945 after it.

Not all pre-VQ SA's were made the same way. At least some where touched up or one could consider them to be poor spherics or they were "experiments" ... I'll leave the latter one in the middle but I can see how this can lead to a lot of confusion.

You don't need a-spherical surfaces to create spherical aberrations, lens designers have a few options to get there. Making parts of the surface aspherical is one of the ways a designer can control how much and where the aberration starts in function of iris opening.

Easiest example is the simple meniscus and an iris, doesn't get more simple than this ... and then there is all the rest in terms of design ...

[Mark Sawyer]

Just a reminder - the SemiAchromatic had no aspheric surfaces... P&S only made one lens, Visual Quality, with an aspheric surface and no Pictorialist of consequence used that lens... nonetheless Cooke modeled their modern PS945 after it.

Not all pre-VQ SA's were made the same way. At least some where touched up or one could consider them to be poor spherics or they were "experiments" ... I'll leave the latter one in the middle but I can see how this can lead to a lot of confusion...

Russ and Rudi, do either of you have some specifics on this? I honestly don't know if Smith aspherized lenses other than the VQ. The point of my last post is that there could be bad information out there. I've been under the impression for a long time that the Semi-Achromats were hand-aspherized, and the variation from the handwork was why Coburn had at least 15 of them. As he wrote in The Question of Diffusion. A Tribute to the P. & S. Semi-Achromatic Lenses, "It seems to me that each of the S.A. lenses has a charm of its own. They have Individuality."

Meanwhile, an article in The Photo Miniature notes, "In practice, however, the results obtained with it were so variable and inconsistent that it was decided to introduce a lens giving firmer quality of definition, with a flatter field, and capable of bringing the chemical and visual images closer together, thus permitting of simpler and more certain use." ...which sounds like more of a machine-made consistency.

But Barbara Lowrey of Cooke Optics has noted the Cooke lab found evidence of hand-worked surfaces on the VQ when they were reverse-engineering it for the PS945, so what do I know...

Not a big deal, I'm just personally curious bout a lens I'll never be able to afford anyways.

You don't need a-spherical surfaces to create spherical aberrations, lens designers have a few options to get there....

That I know, and in modern lenses, aspherical grinds are one solution to getting rid of the spherical aberration inherent in all simple spherically ground lenses.

[Amedeus]

Russ and Rudi, do either of you have some specifics on this? I honestly don't know if Smith aspherized lenses other than the VQ.

Mark,

i wondered about the different characters of the P&S lenses (and other SF lenses for that matter) so I embarked a year of so ago on a continuing project to analyze lenses I have access to using SEM, CMM and interferometry. It's going to be a long haul project as the resources (time and money) are as usual limited. Access to lenses is as you can expect is not necessarily easy (I don't necessarily have al the test equipment in my garage either ... so I'm bartering/paying for services ... )

As far as I can and I'm willing to tell right now, there appears to be a difference between P&S lenses without serial number versus the ones with serial number. The latter seem to be made more consistent while the former might have been individual experiments, one will never know for sure unless sufficient lenses out of the populations are characterized and statistical relevance is established.

I do plan publishing about this when I feel there is significant repeatable data out there to substantiate "claims", it is about statistical relevance and not about a single event ... as for now this data is adding to the rumors you've pointed out below.

Keep also in mind that tolerances and capabilities might play a role in all of this. We make spherical surfaces with higher precision now than 100 years ago so from a relative perspective ... when is something truly spherical ? The latter question is a thesis in itself ... even proving that one's test process is adequate to tell the difference is an undertaking of MSA or gauge R/R proportion.

I wouldn't be surprised that at one point the designer settled for an automated process rather than manual touch up as you pointed out for consistency. You don't need manual touch up to get to an "aspheric" surface. Again, without access to the original equipment or notes from production, there's nothing "for sure"

My 2 cents to added uncertainty.