Parvin Tele-Photo circa 1893

[Richard Rankin]

I picked up this odd duck of a lens the other day. It is a Parvin Tele-Photo , Pat. Febry 21-93, "6 1/2 x 8 1/2" and was marketed by Williams Brown and Earle of Philadelphia as sole agents.

Google books has a couple of mentions. In one, an 1894 mention that The Smithsonian tested the lens and bought some for the Astro-Physical Observatory. Another is an 1893 mention in the Jewellers Circular and Horological Review mentioning that the Parvin takes "a picture nearly 6-fold larger than a rapid rectilinear from the same standpoint".

Albert Parvin received the Merit Award in Engineering for 1895 from the Franklin Institute for this lens design.

Nothing in the Lens Vade Mecum.

Looks to be about 16" focal length, and is cut for stops. The internal ledge for the stops restricts this to around f25 or so.

Does anyone have any additional info about this thing? Thanks!

[CCHarrison]

google hit

Journal of the Franklin Institute of the State of Pennsylvania, Volume 135, 1893

"Another experimenter, who became interested in the new departure in photographic optics, was Mr. Albert B. Parvin, also of this city, and I now have the honor to introduce to you for your inspection and consideration a result of his labors, viz: A new tele-photo lens, which differs in construction and action from its European prototypes.

In the first place, the new objective is contained within an ordinary lens tube two and five-eighths inches long, and it requires no delicate adjustment prior to taking the camera focus. Secondly, the remarkable rapidity or speed with which the new lens works, in direct contrast to the European systems which are not rapid enough for instantaneous work. A specimen print which I have here to show you, according to the maker, was taken on a cloudy day, at half a mile range, stop f/42, in one-fiftieth of a second. The picture certainly shows excellent illumination and sharp definition, even the cordage of the vessel being clearly cut. Another pecularity claimed for this new tele-photo lens is its covering power. The len s here for your inspection is one and threethirty-seconds of an inch in diameter, equal to what is known as a Ross 6x5 lens, yet, as you will perceive by the specimens here shown, it more than covers a tox 12 plate sharply, while the same test (C), made with a 5x8 Beck lens, which is about an inch and a quarter in diameter, falls far short of covering the plate.

As to the "tele-focal" powers of the new lens (if I may use the term), a comparison of the two views, marked A and B, will give some idea of its scope. Both are taken from the same standpoint, the former (A) is taken with the new Parvin lens, the latter (B) with a Beck lens of almost the same diameter. These three experiments A B were all made by the inventor from the same standpoint. Exposure, A two seconds, B three seconds, C two seconds, stop in all //64.

An examination of the Parvin picture will show the depth of focus and its claim to absolute rectilinearity.

As to my personal experience with the new tele-photo objective, I will state that upon two occasions I had an opportunity to test the new objective, both experiments were, however, confined exclusively to trials in focussing upon the ground glass, the main object being to calculate the magnification, and determine its powers and possibilities in actual practice and its adaptation for scientific work, such as falls to the every-day lot of the naturalists or geologists, by affording means to record photographically objects which are beyond the focal length of the ordinary objective. These comparative tests, made with both 8x5 Darlot objectives, showed that the magnification of the new lens was about five times greater than the regular objectives of equal diameter.

Excellent results were shown upon formations distant by actual stepping, from 100 to 1,000 yards, the finest details being sharp and clear-cut with an open aperture, the camera extension being fifteen inches.

In focussing upon distant objects, distant from three to four miles, such as the Fairmount Observatory from Belmont, the iron rods and structure showed plain and distinct against the sky.

The same may be said of the tower of the new City Hall, distant four miles from the same standpoint, which with the old objectives from the same standpoint are hardly discernible. These results led me to believe that tele-photo lenses of this character, i. e., of a system of moderate amplification, would be of considerable value in the hands of the scientific student and photographic tourist. Such lenses, as they become better known, will no doubt prove indispensable to the amateur and tourist, as it will give opportunities for obtaining views and bits of detail otherwise unobtainable with the means which under ordinary circumstances are within the reach of the travelling amateur. Such lenses offer to him magnification in addition to rapid work and sharp definition. For very close work, such as laboratory or studio work, I find that the new lens is not so well adapted as some of the older forms of objectives, the magnification being a fixed one. This, however, is not to be taken as detrimental to the new objective, as the sample furnished for experiment was intended entirely for distant outside work. It is stated, that in the near future, specimens will be forthcoming where the same principle is adapted for interior work.

In conclusion, I will state that no such extreme telescopic properties are claimed for the new Parvin lens as have been shown by the German and English lenses. I allude to such views as that of Mont Blanc, taken from Belleview near Geneva, at a distance of forty-four miles, by Fred Boissonas, which was lately exhibited in this city. Further, this view was made in a camera built expressly for the purpose, with a draw of sixty-six inches, the time of exposure being ten minutes.

The claim made for this Philadelphia tele-photo lens is that it is a simple and practical objective, having a fixed system of magnification, the whole being constructed for ordinary use in the hands of the average photographer of the day.

One of the greatest advantages claimed for the new lens, over all the European telescopic lens system, is the fact that the new lens works instantaneously even when stopped down to f/45. The Pkotographische Nachrichten, published in Berlin no later than April 27th last (p. 216), distinctly mentions that the German tele-photo objectives are not suited for instantaneous work. Here we have proof of the claim of the new American objective. I submit for your inspection a number of comparative photographs, all made by the inventor of the new lens, which will enable you to judge intelligently of the magnification, covering power rectilinearity and speed, some of them being produced by an exposure of one-fiftieth of a second.

I now leave the subject in your hand for further investigation."



I would think a pretty scarce lens....

Dan

[CCHarrison]

Patent right online...cool

http://www.google.com/patents?id=21t2AAAAEBAJ&pg=PA2&dq=parvin+lens&hl=en&ei=V6bdTZHUBsTTgAfutKD_Dw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCwQ6AEwAg#v=onepage&q=parvin%20lens&f=false


Dan

[Jim Galli]

Richard, it's the same as the one I bought a year or so ago that was stuck doggy style to a little #4 Darlot RR lens that I played with and sold. Mine seems to be like 21" focus or so. Not sure what they're good for. Maybe if we talk about them a mystique will build and we can sell 'em for big bucks. Or not. So, there's at least 2 of them. Any Parvin collectors out there??

[Richard Rankin]

Thanks, Dan. I didn't even know that you could find old patents like that online. It is a very tiny lens for the coverage. I'll try and post some pix of it tomorrow.

We've had dark and rain all day but I did get a few minutes of light. On an 8x10, I pointed it at a structure down the railroad tracks near my house. This structure holds some sort of signals for the trains going by, and is my normal 'infinity focus'. Even with the low light, I could tell that the structure was much larger than I've ever seen before on the ground glass. As I was looking, a train passed by and I could see far more detail than I've ever picked up before.

I'm not sure why it is only rated for whole plate. It looked to me like it easily covered the 8x10, but, as I said, the light levels were pretty low. I can't wait to try this in broad daylight.

[Richard Rankin]

Jim, from what little I've read, it isn't meant to be piggy-backed but used as a lens on its own. Is yours a whole plate size or is it marked something else?

[Richard Rankin]

Man, you gotta love LFPF, don't you?

[Steven Tribe]

I remember the Parvin + Darlot being listed some time ago. A quick look then made me think it was a tele-addition. Was atracted by the possibility it was a novel misread of a Darlot engraving!

[cdholden]

Patent right online...cool

http://www.google.com/patents?id=21t2AAAAEBAJ&pg=PA2&dq=parvin+lens&hl=en&ei=V6bdTZHUBsTTgAfutKD_Dw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCwQ6AEwAg#v=onepage&q=parvin%20lens&f=false


Dan

Richard,
To look at the drawing of the lens, at first glance it would appear to be a plain ol' RR (still not a bad thing). It looks like you got a bonus this time.

Chris

[Richard Rankin]

Richard,
To look at the drawing of the lens, at first glance it would appear to be a plain ol' RR (still not a bad thing). It looks like you got a bonus this time.

Chris

Chris,

The lenses are not symmetrical, so it's not an RR. I haven't deciphered the patent app yet, but that much is clear. And, according to the patent, EVERY surface has a different radius as calculated by his mathematical formula.

Richard

[cdholden]

I see what you mean. I had noticed figures 2 & 3 looked to be about the same size, but I missed the cutaways in 4&5. After looking at those closely, the front and rear are significantly different. Thanks for catching my mistake.

[Jim Galli]

Actually the layout is closer to a Verito's than anything, but with sharp corrections. The doublet is almost like a petzval but with a curve at the rear that seems to be offset by the single negative at the back. I'm no opticien though.