Tidbit: Kodak Ektar Lenses

[neil poulsen]

Call me uninformed, but I learned only recently that Kodak optimized their Ektar lenses for shooting Ektachrome film. I thought this was interesting, and that it was worth mentioning.

[Bruce Watson]

Call me uninformed, but I learned only recently that Kodak optimized their Ektar lenses for shooting Ektachrome film. I thought this was interesting, and that it was worth mentioning.

Optimized for Ektachrome? In what way?

[Jim Galli]

They were APO when APO wasn't cool.

[Vick Ko]

Yes, I just read that EKTAR's were designed to be apo-chromatic.

Just think if they had engraved APO on their lenses, they would be fetching an order of magnitude more $$$.

I just watched a Bessa II with an APO Lanthar lens sell for $4.2K USD, while I picked up an Ektar 127mm with Compur shutter for a very economical bid.

Vick

[John Kasaian]

Jim,

When did Kodak start doing this? Which Ektars were apo? I would suspect the models that were copied after the artars as well as the graphic arts lenses might well be apo, but the tessars or the gnauss designs?

[Glenn Thoreson]

APO? That's news to me. The Commercial Ektars are the most highly corrected. Very nearly APO, but no cigar. Optimized for Ektachrome? That's another new one to me. Highly corrected for color work, but Ektachrome? Nah.

[Vick Ko]

Here's a reference from the large format group:

http://www.largeformatphotography.info/classic-experts.html

...quote: " Ektars
Ektar was used by Kodak as a trade name for its premium lenses. There were a number of generic designs used for them. Ektars were all very high quality lenses. The ones made for press and view cameras were mostly Tessar types. Exceptions are the Wide Field Ektars, which are four element air-spaced lenses of the "Double Gause" type, and the 203mm f/7.7 Ektar which is a four-element air-spaced Dialye type, made slightly non-symetrical to improve its correction for distant objects.

All of these lenses are completely corrected for lateral color and were intended for color photography. Some Ektars were coated as early as 1940. These include the series of f/6.3 lenses marked "Eastman Ektar", which are the predicessors of the Commerical Ektar series. The early coatings were soft and applied only to inside surfaces. ...."

[Struan Gray]

Gauss. G-A-U-S-S. Gauss.

Write this out one hundred times by the end of break:

http://upload.wikimedia.org/math/9/3/0/930b3b1628079e6303d515a46d5a83d8.png

[Ole Tjugen]

...

All of these lenses are completely corrected for lateral color and were intended for color photography. Some Ektars were coated as early as 1940. These include the series of f/6.3 lenses marked "Eastman Ektar", which are the predicessors of the Commerical Ektar series. The early coatings were soft and applied only to inside surfaces. ...."

There's a big difference between "completely corrected for lateral colour" and "Apochromatic".

No, Ektars are not APO - at least not from this information.

[Paul Fitzgerald]

Hi there,

I do have an APO Ektar sitting in front of me, it says:

Kodak Process Ektar Lens
18 inch f/10 APOCHROMATIC ETxxx (1949)
strange looking aperture, 'radioactive' glass, 4 element "artar" type, quick-disconnect mount, adjustable aperture scale for bellow extension, center filter slot, really expensive looking for it's time.

I'm sure Kodak knew what APO means when they were making Commercial Ektars. Didn't Zeiss make APO Tessars before WWII? Wollensak process lenses? Rodenstock? B&L? Voigtlander? I don't think Kodak would have missed-out on the marketing scheme if they could have used it.

Sorry to rain on the parade.

[Ole Tjugen]

APO-somethingorother was made well before WWI! My 1910 book list a lot of available APO-lenses for repro work. including lenses from Rodenstock, Steinheil, Stäble, Voigtländer and Zeiss.

I'm absolutely certain that they knew what "apocromatic" meant. I'm not so convinced that the "apo" designation means the same today, though...

[Paul Fitzgerald]

Hi there,

Correction for the previous, the Process Ektar is NOT a 4 element 'artar' type. On closer inspection, disassembled for cleaning, it has a biconvex outer element, an air space and what appears to be a bi-concave cemented triplet as the inner element. Only the outer elements have the brown tint like thorium glass, so it should bleach out with U.V.. Who knows, this might turn out to be a useable lens instead of a really strange looking paperweight. :D

[cobalt]

Don't really care what type my 14 inch eastman ektar is...it is superb.

[Jim Noel]

Cobalt -
Yours is the best answer yet!!!!

[paulr]

Apo actually means different things to different companies. They measure slightly differently; the differences are too arcane to matter in the real world.

It also means something different for process lenses (the original apo lenses) and general purpose lenses.

The only truly apo lenses (by the anectdotal definition of focussing all visible wavelengths at the same plane and same magnification) are microscope lenses.

I owned one Ektar lens ... it was a 152mm (not sure if this was 'commercial' or not). it wasn't at all sharp so i sold it.

[Scott Davis]

I owned one Ektar lens ... it was a 152mm (not sure if this was 'commercial' or not). it wasn't at all sharp so i sold it.

Even Kodak turned out a few dogs in those days. I suspect you got a bad example of one of their weaker designs. The 152 if I recall from reading about standard lenses for the Speed/Crown Graphics, was not considered to be their best design. The 127 Ektar, however, was fantastic, as was the 203. The big 5x7/8x10 lenses are all fantastic - I own a 12" F6.3 Commercial Ektar, a 14" f6.3 Commercial Ektar, and a 12" F4.5 Ektar, and all are wonderful optics, producing brilliantly sharp images with first-rate color rendition. They also have very nice OOFAs (Out Of Focus Areas) both in front of and behind the subject.

[venchka]

Bump. A blast from the past.

While wandering about in Al Gore's internet, I stumpled upon this from Camerapedia.....


According to Kodak, the performance characteristics of all Kodak Ektar Lenses were:

1. A Kodak Ektar Lens was of outstanding excellence and of preeminent quality.

2. The degree of all residual aberrations in Kodak Ektars was negligible. For example, astigmatism, which is normally present in small amounts in all lenses, had been reduced to a new low.

3. Kodak Ektar Lenses were carefully corrected for lateral chromatic aberration, which was particularly important when Kodachrome transparencies made with these lenses were to be reproduced photomechanically or by other color printing processes.

4. An Ektar lens is focused as a complete unit.

5. In black-and-white photography, the quality of Kodak Ektar Lenses is most evident when fine- grain negative materials are used or when a small portion of a negative is to be considerably enlarged. The Kodak Ektars were also suited to making negatives from which photomural enlargements are to be made.

6. Relative aperture (diaphragm) markings were accurate within extremely close limits.

In all, the Ektars had a reputation for very high quality and consistency, comparable to the best European manufacturers. The use of the Ektar lens brand name appears to have been strictly limited to Kodak's best lenses. Perhaps the last generally available Ektars were the 26mm f/2.7 units on the top of the line 110 Instamatic cameras.
...
This lens is corrected to a very high degree and is especially well corrected for transverse chromatic aberration or lateral color; it is therefore ideally suited to Kodachrome and black- and-white photography. Each lens was tested for exact register of the images of the three primary colors. The lens was set up so that the light from the test object passes through the lens obliquely. The rectangles were made of colored gelatin, each passing a narrow band of the spectrum. If the lens had been properly made and assembled, the narrow black lines through the rectangles on the test object would be continuous in the test exposure. A test negative was made for each of these lenses, and kept on file.


KODAK LENSES (http://www.camerapedia.org/wiki/Kodak_lenses)

So it seems that if Kodak optimized their lenses for any film it was Kodachrome. Which makes perfect sense to me. It was, after all, THE color film of choice among professionals and discerning amateurs alike.

Available in sheets too.

Drool! :)

I have new found respect for my 127mm f/4.7 Ektar lens. I shall endeavor to use it more often.

[Dan Fromm]

Hmm. To learn more about how well various Ektars are corrected, visit www.dioptrique.info and look at Eric's calculations for them. None of the ones whose prescriptions he took from US Patents (hint, he gives the patent numbers, go to the patents to see the claims made for the designs) is an apochromat, some have astigmatism problems.

What's in Camerapedia is more often than not fanciful.

And whatever you do, remember that Ektar is a trade name, not a design type. When you're done with the exercise Struan set you, write "Ektar is a trade name, not a design type" one hundred times.

[venchka]

I knew that.

However, the original hypothesis was the Ektars were optimized for Ektachrome. That never did seem correct to me. If Kodak is quoted, rightly or wrongly, as having tested the Ektars with the 3 layers of the Kodachrome emulsion, that seems more plausible, technically and commercially, to me.

1. Ektar is a trade name for a series of professional quality lenses.
2. Ektar is a

Merry Christmas!

[Drew Wiley]

My older brother used to sell these things. I remember him telling me quite plainly that
Commercial Ektars were themselves graded for relative quality, with some kind of recognizable system. I don't know if this involved serial numbers or not. So within this class you had good lenses and even better ones. But I've never heard of them being
legitimately classified as apochromatic, even though they were considered excellent
color lenses in their time. Most modern lenses are probably better corrected, and better coated too.

[Dan Fromm]

Wayne, engineers design, marketers puff. Why should a sensible person like you take obvious marketing fluff seriously? Remember, the well-meaning innocents who post all sorts of information, some of it, alas, misinformation, on websites aren't particularly critical. Being uncritical goes with meaning well and innocence.

Happy new year to you,

Dan

[Nathan Potter]

Dan engineers also mis-design. It's the job of marketers to explain that the variants were designed in on purpose. Wasn't Kodak involved in the faulty design of the objective in the orbiting telescope - the one that needed to be retrofitted in space using a correction element?

Nate Potter, Austin TX.

[Dan Fromm]

Dan engineers also mis-design. It's the job of marketers to explain that the variants were designed in on purpose. Wasn't Kodak involved in the faulty design of the objective in the orbiting telescope - the one that needed to be retrofitted in space using a correction element?

Nate Potter, Austin TX.I always thought the miscreant was Perkin-Elmer, could well be mistaken.

Apropos of mis-design, Richard Knoppow has always insisted that thanks to a design/calculation error Wollensak tessar type Raptars (and, for all I know, tessar type Velostigmats) have much worse coma than other tessars. And if you'll visit www.dioptrique.info you'll see that not all lenses in the same design family, e.g., tessars, are equally good.

[Mark Sampson]

Perkin-Elmer did indeed make the mirror on the Hubble space telescope. They came in at a lower price than Kodak, partly because of P-E's less rigorous, and less expensive, testing program. That testing program did not find the manufacturing errors which caused the Hubble to have such poor optical quality, and made the repair necessary. The (correctly made) Kodak backup mirror is on display at the Smithsonian's Air & Space museum in Washington.
Not that these two things are really connected; the Kodak Ektar lenses that we're concerned with here were designed in the 1940s and the last ones were made around 1966. The Hubble mirror and other telescope optics were made by an entirely different division of Kodak, and thse designs came much later, presumably beginning in the 1980s. FWIW, I don't believe that any Ektar lenses were "optimized for Ektachrome", or that there was any kind of unwritten quality grading among the Ektars. Apochromatic? I can't judge that, but I doubt it- except in the case of the Process Ektars, whre that kind of correction is both useful and necessary.

[Bjorn Nilsson]

Now, wouldn't you be surprised to read something like: "This Schneider K. lens benefits greatly from the use of our centerfilter 3c, but the xxx from Rodenstock work equally good."
Or, filling up on Shell gas stations only, as their petrol is advertised to be "better" with some super additive. (While the truth is that the Shell trucks goes to fill up at whichever refinery or depot which is closest. There is no difference in between normal type gasoline, period. (I know this for facts, as I've worked in the business.) On some markets Shell, BP et al. does have some high-octane special soup, which sells under different names at a premium, but that's not the topic here.)

What I trying to say is that of course Kodak will say that their range of lenses is (was) optimized for Kodak film. Anything else would have been a grosse error from the marketing department.

//Björn

[Drew Wiley]

Pure trivia - but Kodak did not make the correction lenses for the Hubble, nor did they
have the technical ability to do so. They might have been involved in the paperwork
end of the contract or something, but the work was actually done by an outfit which
specializes in aspherics. I should know - I was part of the supply chain for the sealants. Probably best not to divulge the details, but these folks make the surveillance optics for the DEA, Coast Guard, NSA, etc. If you can afford a hundred grand for a camera lens the quality will make everything we view camera uses know look about as corrected as an 1860's Petzval. I seen some of the shots from some of
these things and they're a little hard to believe at times. And yes, when it comes to the highest quality images, real film and real spy planes are involved, and real optical
enlargers, which are also specially designed.

[David Lindquist]

Not sure anyone here has asserted Kodak made the correction lens. They did make a back-up mirror lens (which did not have the error of the lens that ended up in the Hubble, needing a correction lens added) . As is often the case, Google can be your friend. Using "Kodak Hubble" yielded several useful hits including this from NASA:
http://www.gsfc.nasa.gov/news-release/releases/2001/h01-185.htm
David

[Bernard Kaye]

Kodak's literature spoke of design for Kodachrome transparency film & B & W & color negative film; Ektachrome being a figment of its parents' imagination; but the color film results of fully coated Ektars needs no excuses. Bernie Kaye

[Dan Fromm]

Bernie, not to quarrel or anything, but what does coating have to do with anything but controlling flare and improving transmission?

I ask because I have a number of uncoated lenses, including a 101/4.5 Ektar, that produce very good color transparencies. The colors are correct, as saturated as they should be, etc. And some of these lenses were made before 1914, i.e., their designers didn't have color film in mind. They did, though, have the idea of minimal chromatic aberration firmly in mind.

I also ask because as far as I can tell the idea that only coated lenses are suitable for shooting color is another canard launched by marketers. Voigtlaender's, to be exact. There's a reason why all those nice pre-WWII Voigtlaender folders had built-in yellow filters; their lenses weren't well corrected for color, were acceptably sharp only with monochromatic light. After the war, when it became clear that color film wasn't going to go away Voigtlaender redesigned their lenses to improve color corrections and began coating. The two changes happened synchronously but independently, if you see what I mean, and the marketers conflated them.

Cheers,

Dan

p.s. The 80/3.5 Color Skopar on my Perkeo II is, as best as I can tell, not particularly sharp. My uncoated 101/4.5 Ektar is much sharper. But both give me color transparencies with correct etc. color.

[Bernard Kaye]

Dan,
No argument from me. I cherish older lenses such as Protars, Tessars, Heliars and Kodak's. My point in writing was that the Ektars were advertised for Kodachrome, B & W and Kodacolor, not later Ektachrome; now watch the girls and boys shoot me down.
Bernie Kaye

[Sevo]

I also ask because as far as I can tell the idea that only coated lenses are suitable for shooting color is another canard launched by marketers. Voigtlaender's, to be exact. There's a reason why all those nice pre-WWII Voigtlaender folders had built-in yellow filters; their lenses weren't well corrected for color, were acceptably sharp only with monochromatic light. After the war, when it became clear that color film wasn't going to go away Voigtlaender redesigned their lenses to improve color corrections and began coating. The two changes happened synchronously but independently, if you see what I mean, and the marketers conflated them.


Sounds nice - however I have never noticed worse colour rendition or chromatic aberration from pre war Heliars and Skopars compared to their "Color" brethren, which does not suggest a redesign.

I think it is more likely that the higher contrast on coated lenses was considered to be of particular relevance for colour work, given that the then common film types (even more so in Germany, where Agfacolor was dominant) already had very low colour contrast, and that any loss of contrast could not be compensated in printing like in b/w.

[Clarence Rhymer]

Hello Paul,

Kodak Process Ektar Lens
18 inch f/10 APOCHROMATIC ETxxx (1949)

Do you still have this lens? I have one, but am unsure about which way round the biconvex cells and the cemented triplets go (the lens is disassembled). I haven't checked if the biconvex elements have the same radius on both sides, so maybe they could go in either way. The cemented triplets appear to have one end element thicker/thinner. I am aware that the biconvex elements go at each end with an airspace next, then the triplets. I just don't want to get the groups in the wrong way round.

I couldn't find it in the vade mecum or on www.dioptrique.info but I miss a lot.

Thank you.

Cheers,
Clarence

[Lynn Jones]

At Kodak, the term "Ektar" was a quality standard in any given lens type. These included resolution, contrast, common abberations, color quality, etc. Some were tessar type, some of the best were heliar/pentac types, some were high speedmotion picture lenses.

Lynn

[Paul Fitzgerald]

Hi Clarence,

I will have to open it up and check, I'll get back over the weekend.

[neil poulsen]

Call me uninformed, but I learned only recently that Kodak optimized their Ektar lenses for shooting Ektachrome film. I thought this was interesting, and that it was worth mentioning.

I got this from a friend who passed away just over a year ago. He was a Hollywood photographer during the 40's through 70's.

[Paul Fitzgerald]

Hi Clarence,

the biconvex lens has 2 curves, sharper faces out, flatter faces in.
metal spacer ring next.
triplet thinnest end element faces out
retainer ring.

both cells appear to be identical so don't mix-up the pieces.
fitting of the glass/cell seems to be air-tight, you may want to polish the interior of the cell for easier fit.

Hope it's a help

[Clarence Rhymer]

Hello Paul,

Yes, that is a great help. I had disassembled the lens and stored the cells in the proper order and orientation. But, as sometimes happens, they got moved and mixed up.

Thank you again.

Cheers,
Clarence