Repairing Kodak Anastigmat and Kodak Ektar Cine Lenses

[John H. Tischler]

Hi,

I have been looking everywhere and have found absolutely NOTHING on how to tear and and repair/lubricate old C and S mount cine lenses by Kodak and Schneider. These lenses aren't worth the cost of sending out, but are too expensive to toss. I'd love to learn how to work on them. If anyone has videos, manuals, advice or links to help, I'd be VERY grateful.

John

[John H. Tischler]

Follow up: In the lens shown in this post, the focus is absolutely frozen with the circled screw installed, but seems fine with it removed. Since I'm not sure how the lens works, I don't know if something is frozen up inside or if the screw is supposed to be removed.

[Dom Jaeger]

Those types of lenses are not too difficult to relubricate, although there is always the need to be careful to mark exactly where the multi-start helical threads screw together and how far they are screwed in to preserve the focus calibration. Usually there are 2 or 3 threaded rings that screw into each other with a keyway that prevents the inner optical unit from rotating as it telescopes. A stop screw often needs to be removed to fully unscew the rings.

 

That screw that locks the focus seems like it might be overlong or something, not a design feature I suspect.

 

You may need to carefully disassemble one yourself and risk making it unuseable to get an idea of how those types of lenses work. Hard to describe it properly. Feel free to post photos and ask questions here.

[John H. Tischler]

That screw is out a bit in the photo intentionally. With the screw completely out, the lens SEEMS to focus normally. But I doubt that they would have just put a screw hole there for no reason. When I unscrew the base part, there is a long channel along the aluminum shaft. The screw sets there. Once it's in there, NOTHING but the aperture will turn.

 

[Dom Jaeger]

So the screw acts as a key in the channel, stopping the lens from rotating as it telescopes. If the screw is too long or wide, it will jam in the channel instead of sliding. Usually those key screws have a cylindrical end where they slide in a channel, and the thread up near the head. Its possible someone replaced it with the wrong screw.

[John H. Tischler]

So the screw acts as a key in the channel, stopping the lens from rotating as it telescopes. If the screw is too long or wide, it will jam in the channel instead of sliding. Usually those key screws have a cylindrical end where they slide in a channel, and the thread up near the head. Its possible someone replaced it with the wrong screw.

Since there is an external screw hole that goes through the S mount casing, I don't see how anything could "slide" up

[Philip Forrest]

John, I'm in Philadelphia and would love to talk old Kodak optics with you. I have a bit of a collection going and have had all of them apart for cleaning and lubrication.

Phil Forrest 

[Robert Hart]

The screw may have been replaced if an original fell out and was lost. Does your lens's screw have a narrower smooth toe with no threads on its end. It may be that the screw is screwing in but the threads may be interfering with the sides of the squarecut channel and stopping it from sliding back and forth past the screw. If the screw is too long, it may be bottoming out in the squarecut channel and jamming the optical block against the barrel on the opposite side.

[Ivan Zivojinovic]

On 7/24/2019 at 2:22 PM, Philip Forrest said:

John, I'm in Philadelphia and would love to talk old Kodak optics with you. I have a bit of a collection going and have had all of them apart for cleaning and lubrication.

Phil Forrest 

Hello Phil, how can i contact you? Got some Kodak cine glass that i would like to clean and lubricate so any help would be appreciated

[Okto Simaia]

On 1/11/2019 at 12:21 AM, John H. Tischler said:

Since there is an external screw hole that goes through the S mount casing, I don't see how anything could "slide" up

Necroposting for future Googlers: the screw is almost certainly meant to ride in this channel, to keep the lens from rotating in the mount when focused. The most likely reason the lens wont budge when the screw is tightened down is that it's binding in this slot (either because it's the wrong size or is damaged). The test is to remove the screw and the mount and try to slide the screw in the slot with the mount removed. It should slide freely, but not too loosely. Too tight a fit, it will increase the force needed on the focus helical to move the optical block, too loose and the optical block will turn in the mount and the tip of the screw will bind (due to not being square to the slot) and have the same effect.