Please help me identify lens: Scientific Lens Co.

[edgately]

I am trying to confirm the optical design of a lens I just purchased.

Please see photos attached. One image with lens elements arranged left to right; front, middle and rear. Second image is all of the components.

Markings on barrel:

PORTRAIT LENS F.4
8X10
The Scientific Lens Co. NEW - YORK.
12139

Many thanks.
Ed

[Steven Tribe]

You will find lots of info and gossip if you search titles with "scientific" as the only key word.

[CCHarrison]

First incorporated in Jan 1904....

Nehring was selling lenses starting in the late 1890's under his own name. He published a lens catalog in 1900. He continued to sell under various names until around 1910.

Nehring was involved with the SL Company (supplying them lenses), and patented a lens and assigned it to the SL Co in 1904 (Patent 761390 ). In 1908, there were investigations going on of both the company and Nehring...

From Camera Craft Vol 17, 1910

More "Honest Lenses for an Honest Price"

Months and months ago we learned, through a four-page "list" that costs fifty cents a year, that Nehring had induced the Scientific Lens Company to continue the manufacture of lenses from his formulae and patents. This "Lens Company" must be quite powerless in the face of Mr. Nehring's wonderful persuasive powers. As further evidence along this line, a circular letter, under date of November nineteenth, advises that the photographic department of the Scientific Lens Company, its "plant and formulae." have been sold to Alfred Koehler. Mr. Koehler, we are told, was "selected" by Mr. Nehring as the most desirable successor; and that, "in selecting him as my successor, I feel that I have kept faith with the fraternity." We are not advised as to the name or nature of this "fraternity," possibly because it is obviously unnecessary. Mr. Nehring's wholesouled generosity and his confidence in the existence of a further supply of confiding souls is clearly shown by the reckless manner in which he asks "all my friends and users of my lenses to transfer their confidence to Mr. Alfred Koehler." Observe the lavish prodigality embodied in this request, which, if complied with, leaves Mr. Nehring without even the confidence of his friends, let alone that of the users of his lenses. Pending the printing of a "higher price list," these honest lenses can be obtained at the old honest prices; Mr. Koehler going to the trouble of testing and guaranteeing them, "honest lenses," it would seem, not being above suspicion. We assume that the new prices will, although higher than the present "honest" ones, comply with the standard of honesty enjoyed by the lenses. If any of our readers have any confidence in the Scientific Lens Company, Lens Nehring, or U. Nehring, they will kindly transfer it to Mr. Koehler. Mr. Nehring no longer needs it, and Mr. Koehler is. no doubt, entitled to it under the conditions of the sale.


More data from Google https://www.google.com/search?q=%22scientific+lens+co%22&hl=en&source=lnt&tbs=cdr%3A1%2Ccd_min%3A1904%2Ccd_max%3A1912&tbm=bks

And

http://www.ebay.com/itm/8x10-Portrait-Lens-f4-The-Scientific-Lens-Co-Brass-Petzval-Type-Lens-/121904847158?hash=item1c62185936%3Ag%3A0FsAAOSwPc9WzlsA&nma=true&si=OsS46TQKDru%252BWECtyS%252FX%252FW%252FAH08%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

Dan

148293

[edgately]

I apologize for not mentioning that I have already read every single article from your google search. Almost all of them reference their ocular lens design. The ebay listing you posted is the lens I now own. The most helpful item was the Lens Nehring Ad. I will start cross referencing that.

When I first inspected the lens I did not pull out the rear element because I had what appeared to be the classic petzval layout; front cemented element and air spaced rear elements. Upon further inspection the rear element is a cemented pair which appears to be close to a duplicate of the front pair. The front and rear groups are reversed with the middle element spaced (guessing) 5-10mm from the rear pair. I bumped into another discussion with a person trying to identify a different Scientific Lens Co. lens and made this drawing http://s257.photobucket.com/user/dezzertrat/media/Film%20Photography/Large%20Format/Cameras%20and%20Hardware/Portrait_lens1_dia.jpeg.html

I'm going to shoot with it today and see how it renders.

[CCHarrison]

I did see what looked an additional element. One would think this should be a standard Petzval... let me see what else I can dig up

[Steven Tribe]

This type of lens has definitely been discussed here before (4-5 years ago?). The end result is a modified Petzval. Sometimes this sort of tinkering does sometimes produce a unique result - The Heliar developed from the Cooke patent triplet, for instance. But usually there is no "improvement"!

[goamules]

There were a lot of Petzval modifications over the decades, but if the front and back are cemented, and another element in the middle, that's fairly "modified." Yet, people call about every modern 35mm design under the sun a Double Guass, and they can have different numbers of elements, positions, thicknesses, etc.

[Emil Schildt]

There were a lot of Petzval modifications over the decades, but if the front and back are cemented, and another element in the middle, that's fairly "modified." Yet, people call about every modern 35mm design under the sun a Double Guass, and they can have different numbers of elements, positions, thicknesses, etc.

never heard about a Guass lens... :D

[edgately]

I still have not had a chance to go out and shoot this lens in an an outdoor environment. I am attaching one shot from the lens. It is a 1:1 Selfie Portrait on 8x10 wetplate (alumitype) shot wide open at f4. Image taken with iPhone.
148784

[Jody_S]

That's not bad at all. I own two Scientific Lens Co. lenses and they're both clunkers (8x10 RR & WAR), I am surprised at how nice that looks.

[Nodda Duma]

From a design point of view:


If the front and rear doublets are the same, that may have purposefully been done to reduce fabrication cost. The additional singlet providing necessary additional correction under such a scheme.

It could also be considered a rapid rectilinear stretched to a longer focal length using distance, with additional element necessary for aberration correction.

Kind of an odd approach.

Any reference to the patent number that would list a prescription?


By the way, Petzval is defined today as an objective group with field corrector providing narrower field of view (i.e. alternative to telephoto). NASA's TESS optical design is a modern example. Google for NASA TESS optics and you'll find a layout illustration. Kind of interesting.

[edgately]

Thought I'd toss another example image I made today.http://uploads.tapatalk-cdn.com/20160419/656a20c8f357d1286035c82131aac22e.jpg I'm really feeling pretty happy with this lens.

[Michael Dodd]

Nice work Ed, Something about fast Petzval wet plate work that is very distinct.