Kodak 12" Ektar f4.5 questions

[Bernice Loui]

Kodak Ektars were not made with spacers, Kodak trimmed the lens cell to shutter tube or trimmed the lens barrel which the lens cells to make up the finished lens. If one were to measure the front-rear lens cell spacing on a number of Kodak Ektars, one will discover each one is slightly different in length. This is just one of the many hand crafted and hidden factors that made Kodak Ektars what they are.

Some Ektars still have pencil marks on their lens cells which are assembly notes from when the lens was made.



Bernice

[robertraymer]

Finally had a chance to shoot again today. Im actually thinking that maybe it was just my expectations that are the problem. I have a few of Kodak's earlier anastigmats that I use on my Graflex RB and SpeedGraphic, both of which perform exceptionally wide open. The Ektar, not so much. I compared it to a Rodenstock Sironar N 210 5.6, which is the only other lens I have that will (mostly) cover 8x10 and noticed that the Sironar was tack sharp wide open (much like the anastigmats), where the Ektar did not match it in sharpness until f 11-16. I must say Im a bit disappointed, since I was really hoping to use this lens wide open shooting wet plates, and instead I think Im going to be limited to studio with flash or very bright days.

[Jac@stafford.net]

Kodak Ektars were not made with spacers, Kodak trimmed the lens cell to shutter tube or trimmed the lens barrel which the lens cells to make up the finished lens. If one were to measure the front-rear lens cell spacing on a number of Kodak Ektars, one will discover each one is slightly different in length. This is just one of the many hand crafted and hidden factors that made Kodak Ektars what they are.

Some Ektars still have pencil marks on their lens cells which are assembly notes from when the lens was made.

Solid gold information! Thanks for that.
It should be front page FAQ.

[Greg]

These most probably will not apply to you, but think they are worth mentioning. Three things. 1. Make sure that the rear set of elements is the correct one. Bought a Fujinon lens last year. Image it produced was terrible. Turned out that the rear optics were from another focal length Fujinon. 2. Does it have shims? Once acquired a lens with a lot of shims. Image it produced was mediocre. For the heck of it, removed the shims and the optic demonstratively improved. Who knows why they were added, but I don't think shutter was the original shutter that was sold with the lens. 3. Last off... once bought a lens that gave me a mediocre image at best. Turned out that the front element's retaining ring was very unscrewed and the front element was stuck at its most foward point (think Wollensak Velostigmat with variable soft focus ring), so didn't rattle when you shook the lens.

[Tin Can]

Could we infer from your knowledge that shutter replacement may affect lens performance if not 'zeroed' by an expert?

Kodak Ektars were not made with spacers, Kodak trimmed the lens cell to shutter tube or trimmed the lens barrel which the lens cells to make up the finished lens. If one were to measure the front-rear lens cell spacing on a number of Kodak Ektars, one will discover each one is slightly different in length. This is just one of the many hand crafted and hidden factors that made Kodak Ektars what they are.

Some Ektars still have pencil marks on their lens cells which are assembly notes from when the lens was made.



Bernice

[Bernice Loui]

KODAK 12" F4.5 Ektars came in Kodak Ilex# 5 shutters with threads unique to Kodak Ilex shutters. Think these Kodak-Ilex shutters are mostly the same. It is the Kodak lens cell collars that are made to the needs of the lens cell set.

At some point it might worth while to measure a number (Have a few here and micrometer that would do this nicely) of Kodak Ilex# 5 shutter lens cell mounting distance to see how consistent they are.


Bernice

Could we infer from your knowledge that shutter replacement may affect lens performance if not 'zeroed' by an expert?

[Tin Can]

Bernice,

You have good logic. Cutting cell metal to adjust is wiser than boring shutters to size. Kodak was smart.

I have a couple dissimilar Ektars I use on one shutter.

Thank you

KODAK 12" F4.5 Ektars came in Kodak Ilex# 5 shutters with threads unique to Kodak Ilex shutters. Think these Kodak-Ilex shutters are mostly the same. It is the Kodak lens cell collars that are made to the needs of the lens cell set.

At some point it might worth while to measure a number (Have a few here and micrometer that would do this nicely) of Kodak Ilex# 5 shutter lens cell mounting distance to see how consistent they are.


Bernice

[Bernice Loui]

Folks who designed lenses at Kodak back in those days were far more than smart, they were wise and very practical in the optics they created.

Over the decades of using Kodak Ektar LF lenses, they have given me a very deep appreciation for their work.

Folks like Prof. Rudolf Kingslake no only had a very deep and broad understanding of optics design, they understood human visual perception in profound ways. It is one thing to design then craft a lens by math alone, these folks took the design process that many steps further by tweaking the design using visual assessment. Their production Ektar lenses were hand tweaked-adjusted individually with remarkable quality control.

Rudolf and Hilda Kingslake, both professors with no kids. They dedicated their life to educating others and optics work.

"Rudolf Kingslake was born in 1903 in England. His father was an amateur photographer and young Rudolf became curious about how the lenses on his cameras worked. He had read Photographic Lenses, A Simple Treatise by Conrad Beck and Herbert Andrews that showed sections of lenses; Rudolf wondered why some lenses required six elements and some only four. He soon learned that Imperial College (London, UK) had a department of optics where lens design was taught, so decided to follow up on what was becoming more than just idle curiosity to him."
http://spie.org/newsroom/rudolf-and-...ingslake?SSO=1


The image personality of Kodak Ektars are not for all as the images they produce is not a one size fits all, it does fit some.

The tedious math required to create Kodak Ektar lenses was done by a room full of human "computers". These were gals working together on mechanical calculators to solve a much larger math problem. These were the same gals who worked on various government WW-II programs like the Manhattan Project.

At some point, due to curiosity, I'll take a few of the Kodak Ilex#5 shutters and measure them on the granite surface plate with digital height gauge and post the findings. Think it would be good for any who are interested.




Bernice

-Just noticed this is post# 1000 !

Bernice,

Kodak was smart.

Thank you

[Whir-Click]

We are all deeply in Professor Kingslake’s debt. Quite apart from his role designing some of Kodak’s very best lenses, his book “A History of the Photographic Lens” gives tremendous perspective and insight. His 1974 paper "The Rochester Camera and Lens Companies" is one of the best (and only) resources for understanding the breadth, complexity, and interrelationships of the Rochester optical industry in the 19th and 20th century.

[robertraymer]

Bought a Fujinon W 360mm 6.3 a little bit ago to use for future 8x10 portrait work since I had been unimpressed so far with the 12" Ektar 4.5 and decided to do a direct comparison.

Turns out the Ektar is a far better performer than I had given it credit for being (I think shooting only with natural light on Xray previously may have something to do with it. Im still yet to get ANY Xray portrait Im happy with). I shot both the Fujinon and the Ektar under the same studio light at the same settings on 4x5 Tri-X and the results were almost identical. The Ektar was a bit softer wide open, which is actually rather pleasing to my eye, and stopped down to F32 (the only other aperture I tested) it was tack sharp. Not sure how it performs with color film, as the Commercial Ektars are supposed to be better corrected, but for black and white it definitely shined.

Now I have to decide what to do with the lenses since they are so close in focal length. Keep both and use them both sparingly or just keep one and let the other go to someone who would get more use out of it.