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. 

Using an M42 Focusing Helicoid on the NEX-5

Soulnibbler has asked how I used the M42 mount helicoid on the NEX without adding lots of space.  This may sound complicated but it's amazingly simple.  You just need the right c-mount to NEX adapter.  It's obvious why I choose the c-mount adapter as it's the thinest adapter available for NEX.  It only adds a few millimeters to the length of the helicoid.  Have a look at the picture below:

17-32mm Helicoid on left, C-Mount to NEX adapter on right. 

Note the two threads inside the C-Mount to NEX adapter.  The outer most thread has a 55mm thread while the middle thread size is 42mm.  You simply screw the helicoid onto the C-Mount to NEX adapter.  The one I used was bought from Rainbow Imaging.  They sell on eBay as well as Amazon and their own web site.  This one is very inexpensive for around $15 or less.  Click here to see a sample one they are selling.  I am not connected to them but I bought a few adapters from them and always get excellent service.  The best part, if you are in the USA or Canada, is that they ship from USA (at least when I bought from from eBay).

Perfect marriage -- Helicoid screwed onto the C-Mount adapter.  Very tight fit without lots of space.

Helicoid mounted on the NEX-5.

Helicoid with EL-Nikkor 50mm f2.8.

The helicoid I am using has a 52mm thread on the lens side, instead of the more common M42.  I have many odd lenses that have large rear mount and I find 52mm size is easy to find adapter for, since I have LOTs of useless filters I bought from the Outlet Store.  I just remove the glass and voila, useful adapter rings!  The last pictures shows the EL-Nikkor is mounted on the 52mm filter ring, and in turn, the filter ring is screwed on to the helicoid.  I do need to use electrical tape between the EL-Nikkor and 52mm filter ring, since they fit snuggly, but not very secure by themselves.

Hope you find this useful.