Removing a 21" Kodak Ektanon from a Prism

[Michael Kadillak]

I just acquired a really nice Kodak 21 1/4" Ektanon that was shipped to me in a Kodak 3.5" prism.

The bottom of the barrel lens screws out and the bottom of the front element but not the front element.

Any experience out there as to what I need to do to in getting the front element out of the prism housing?

Thanks in advance!

[Eric Woodbury]

For the record, I'd love a photo of this. Why is there a prism?

Warm solvent soak is my guess, but I don't know anything.

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[Michael Kadillak]

Clear up your PM space and I will send you photos. Trying to send you a PM.

[Keith Pitman]

Clear up your PM space and I will send you photos. Trying to send you a PM.


Post a pic on the Forum. Without seeing it,you’ll get lots of lame suggestions.

[reddesert]

For the record, I'd love a photo of this. Why is there a prism?

Warm solvent soak is my guess, but I don't know anything.



Large front prisms were common on process camera lenses. For example see this Wollensak catalog: http://www.cameraeccentric.com/html/info/wollensak_2.html

I think the main reason was to reverse the image so that it could then be used to make a correct image during reproduction (like the way that a woodblock for printing has to be in reverse).

[Jason Greenberg Motamedi]

On my 21" Kodak Ektanon there was a silver ring on the prism which rotated a few degrees and the lens pulled off. I sold the lens years ago but kept the prism. I never found use for it, but is beautifully made.

[Michael Kadillak]

195790195791195792

As per suggestions attached are images showing the prism with the last image showing the bottom section of the barrel with one section coming off of the top section of the lens. The remaining top section of the lens is what is locked in there. I have only tried to unscrew it with my hands to this point and it is not moving hence my decision to reach out.

[Jason Greenberg Motamedi]

Disregard my suggestion, your prism is different from mine.

[Michael Clark]

Look around for any set screws.

[Michael Kadillak]

Look around for any set screws.

Great suggestion Michael. It appears that there are some small screws on the exterior of the prism that may allow me to take out the outside transparent cover of the prism and possibly other segments. Then I may be able to get a flashlight to the inside of the prism to see if there are any screws holding this from the inside. Will report shortly. Thanks!

[William Whitaker]

Michael,

It looks like the cell for the front element is deep enough to provide fairly good purchase if you were to grab on to it. Have you tried a length of lamp cord as a "wrench"? This is the method I use for stuck cells and recalcitrant filters. More recently I have turned to using the power cord from one of my Apple power supplies. That cable has an insulation that is fairly "sticky" and "grippy". For tougher cases I have a pipe wrench that operates on the same principal. The handle cinches up the strap and adds a bit of lever advantage. But usually I can get things moving with just the lamp cord trick

[Michael Kadillak]

Michael,

It looks like the cell for the front element is deep enough to provide fairly good purchase if you were to grab on to it. Have you tried a length of lamp cord as a "wrench"? This is the method I use for stuck cells and recalcitrant filters. More recently I have turned to using the power cord from one of my Apple power supplies. That cable has an insulation that is fairly "sticky" and "grippy". For tougher cases I have a pipe wrench that operates on the same principal. The handle cinches up the strap and adds a bit of lever advantage. But usually I can get things moving with just the lamp cord trick

I am going to try to ensure that there are no inside mounted screws holding the lens in place and if not, the power cord technique is going to be teed up as a first option. Thanks!

[Keith Pitman]

Another option that has worked well for me is a strap wrench. Same idea as William's. You can get them inexpensively from Harbor Freight: https://www.harborfreight.com/search?q=strap%20wrench.

Sometimes it has helped to put the stuck element in the freezer for a couple of hours. Allows the metal in the joint to contract.

[Michael Kadillak]

OK. I was able to find a set of screws on the front of the prism that upon closer inspection allowed a holding bar to be taken off and this allowed the lens on a lens board to be lifted out of the prism housing. There are three small screws on the outer round section at the intersection of the lens board (you can see them in the image below) and what looks like a retaining ring that is screwed into the lens housing. The screws are quite small and appear to be holding things from unscrewing (which is what I need to do). My gut tells me that these small screws are what is keeping this lens from unscrewing from its housing. I have been looking for very small flat head screw drivers and don't thing I have small enough ones.

195862

[Keith Pitman]

You need a set of jeweler's screwdrivers: https://www.harborfreight.com/16-piece-precision-screwdriver-set-4143.html

You can find better quality elsewhere, but these will work.

[Michael Kadillak]

You need a set of jeweler's screwdrivers: https://www.harborfreight.com/16-piece-precision-screwdriver-set-4143.html

Thanks Keith. I am going to acquire a set of these. Great suggestion.

You can find better quality elsewhere, but these will work.

Thanks. Ordered them.

[Michael Kadillak]

Received the set of micro screw drivers from Harbor Freight and was able to unscrew the three tiny set screws holding the barrel lens in the square metal housing and use the strap wrench also from Harbor Freight to unscrew it. I have a round metal ring attached to the outside of the front lens barrel that I just think I am going to leave there so I am good to get it out and make some photographs with it.

[Mark Sampson]

Best of luck Michael, I think you'll find it a fine lens.