Sunday, September 16, 2012

Kodak Ektanon 3 Inch f2 Projection Lens

This is the last of the few projection lenses that I will look at for a while.  I have always liked loved old Kodak glass, especially the cine lenses, but their earlier projection lenses, before those plastic ones on later models, are equally awesome.  I covered the 50mm f1.2 projection lens here, briefly.  This 3 inch (75mm) f2 is a bit longer, but with a smaller maximum aperture.  Due to its very slender and long design, it was difficult to make it fit in the focusing helicoid, until I found a lens mount from an unknown lens I dismantled.  Now you know why I keep so much junk around, because you never know when the parts could come in handy one day.  Below you will see how I mount the lens to the focusing helicoid, made from the Vivitar 2X teleconverter with macro focusing.

The original lens was longer. I cut the end so that it wont' hit the sensor. Click for larger.

With the lens mount. Lens mount has a 58-55mm step down ring, which will screw onto the helicoid. When the finished, I wrapped electrical tapes on the end part to prevent reflections hitting the sensor. Click for larger.

The whole 9 yards -  with Helicoid and lens hood. Note how many step-up/step-down rings were used. Butt ugly but works.

How does it perform?

Marvelous!  Optically, it reminds me of the Astro-Kino 65mm f1.5 projection lens, but sharper.  It also does not exhibit as much back ground swirl as the Astro, but is still noticeable. The Ektanon 3 inch f2 is the sharpest projection lens I have used.  It's insanely sharp at f2.  The color fringing is also very well controlled. Very happy with what it can do, but like the Astro-Kino 65mm f1.5, it covers only 16mm projection film.  In terms of image coverage, it actually has very little vignetting, but the corners are blurry, especially at infinity focus.  As bad as this sounds, it's also one of its unique signatures: slightly swirling backgrounds, blurry corners with extremely sharp center.  Below are some examples.

Tree Trunks - NEX-5N & Kodak Projection Ektanon 3 inch f2. Click for larger.

Tail Lights - NEX-5N & Kodak Projection Ektanon 3 inch f2. Click for larger.

Bokeh - NEX-5N & Kodak Projection Ektanon 3 inch f2. 


  1. Hello Yu-Lin,

    From reading your blog I know that you are very knowledgeable in the conversion of projection lenses for use on cameras. I have recently acquired a couple projection lenses and was hoping you would be able to give me some advice on how I should approach the project. The lens I am most interested in converting for use either on a nex or micro 4/3 system is a Bell & Howell 16mm 2 inch f/1.2. A JML Optical 56mm f/1.2 also came with the purchase.

    1. Hi Joan,

      You maybe disappointed to hear that the Bell & Howell 2 inch f1.2 lens is not workable on the NEX or Micro 4/3. The flange is too close to the film to achieve working focus distance. I have a few of these lenses I bought from a camera show and found that they don't work at all. Same issue with the Bell & Howell 2 inch f1.4. The JML 56mm f1.2 may work, but I don't have one so not really sure if it can be used and get infinity focus.

    2. Yea I am a little bit disappointed but I am so glad to find out before wasting a lot of energy tinkering with it. Just tried messing around with them hand held and looks like the bell and howell can only be used for macro... the JML doesnt look like it will focus to infinity either but can maybe be used for portraits so might try to play with that one a bit. Thanks so much for responding so quickly :)

    3. If you can find a Kodak Projection Ektagraphic 50mm f1.2, or a Kowa Eiki 50mm f1.2, they would work on both the Micro 4/3 and NEX. I like both of them and they produce very nice pictures. Plus, they are relatively inexpensive for such a large aperture. Good luck.

  2. cool will definitely keep my eyes peeled for those thanks again!

  3. How are you able to achieve the infinity focus on this.
    I have been trying with a f1.6 2 inch version, but having a difficult time of it.
    What distance is the lens from the sensor? I have not cut the end if the lens off, as you did.
    i have posted a link to my Flickr page, so you can see what I did so far.

    I am using it on a Sony NEX 5R.

    any help is most appreciated.

    love the site, and the photos.


    1. I never really measure the distance between the lens and the sensor. It's a try and error process, but you should get a good idea if the lens can reach infinity by putting the lens inside the helicoid and see how far it will go, and then hold it by hand and mount it to the camera and check for infinity focus. I think from your picture, the helicoid is the bottleneck. You probably can not push the lens close enough to the sensor, because the helicoid's rear opening is not large enough, or the lens baffle is too long and you will need to cut it as short as possible.

  4. sorry to bother you again.
    I have a question about the M42 to E mount adapters. apperantly there are 2 types, the regular one, and another that works with the helicoid and other modified lenses. which would you recommend that I purchase, from what you have seen of my modification.

    thank you,


    1. The M42 to E-Mount adapter you need is a very thin (usually 1mm) adapter, like this one I wrote about:, or this one:, first picture, the left most part is the M42 to E-Mount adapter.

  5. Thank you very much.
    I will be looking for a similar M42 adapter.

    From my first question, thank you again. With your suggestion I think I have it figured out.
    It looks like I will have to do a little more modification to the adapter I made so that the lens sits a few more millimeters inside the helicoid I made.
    Of course, if I do the modification to the lens mount on the helicoid, I might have to do this again,cutting the barrel,as you did.