Nikonos lens impossible to remove

[Sirius Glass]

One has to first push the lens towards the camera before turning. I have to look on my other computer for an address of a Nikonos repair man in Los Angeles.

Dean's Camera Repair works on Nikonos. He advised me that a Nikonos II was not worth repairing and advised me to replace it with a Nikonos V and moving the 35mm lens to the replacement camera.

 

[Mr Bill]

... but I have never seen the "insides" of this camera so I can't really use my imagination for that.

Well, until blee1996 (or other?) puts up a photo, the keh link I posted DOES show the back of the 35mm lens. There really is not that much more there. The camera body is essentially just an empty shell with a round bore for the O-ring to seal against. The guts of the camera are all in the removable part that lifts out the top.

If the soon-to-come (?) photos don't help I'll take some measurements on mine just to see what the clearances (should) look like. Don't know if it'll help but might give some insight.

 

[blee1996]

All right, here are some photos @fabulousrice . The lens mount is extremely simple: 2 notches on the lens, and one o-ring. That's it!

 

[mshchem]

Has the grease turned into a rock solid. Helicals with 50 year old grease don't move.

 

[Sirius Glass]

All right, here are some photos @fabulousrice . The lens mount is extremely simple: 2 notches on the lens, and one o-ring. That's it!

There are no O rings in these photographs.

 

[blee1996]

The red line is the o-ring:

 

[Mr Bill]

All right, here are some photos @fabulousrice . The lens mount is extremely simple: 2 notches on the lens, and one o-ring. That's it!

Thanks for taking and posting the photos. They pretty well demonstrate how the thing attaches and seals. As a note I observe that your camera, a Nikonos III, seems to have a removable "lens cup," I will call it (I have no idea the proper name) on the body shell. On my Nikonos II this is a built-in part of the body casting.

 

[Mr Bill]

As I was taking some measurements on the attaching points I first became aware of something interesting (I guess I previously never cared enough to look closer). The bayonet mount on the lens is spring loaded. It can be pulled back approximately 1/16 inch (~1.5 mm); takes several lb of force to do so by hand.

Initially I planned to measure clearances related to the body shell, etc., with respect to getting a secure bayonet attachment. (Thinking that perhaps internal corrosion had made things too tight on the OP's camera to get the lens to come forward enough to get clear of the locating pins.) But this is out the window now, knowing that the spring-loaded bayonet allows plenty of free play (it can move roughly twice the height of the locating pins). So I would rule out the possibility of the OP's bayonet mechanism being stuck. (UNLESS, perhaps, a previous owner had gotten flooded with seawater, and... you can see where this is going.)

Next possibility - that the metal part of the lens that fits inside the camera body shell's "lens cup" (my term) might be stuck. I measure about 0.010 inch (0.25 mm) clearance between the two. This is a considerable amount of mechanical clearance, about the thickness of a business card, and I cannot see this being an issue with a stuck lens.

So in my view this pretty much comes back to the O-ring being stuck.

FWIW I tried something on my own very tight lens, which I was saving as sort of a test bed for methods. Although I was able to rotate my lens, using considerable force, it was still pretty tight (even a good squeek or two while rotating slightly). I put a drop of Dawn dish soap in a couple tablespoons of water, then tried getting this into the joint between lens and camera body. I ended up using an old toothbrush - dipped into the water then working it into the open part of the joint. Then tried rocking the lens a bit. Within about 10 or 15 seconds the gap began to open and close very easily and the lens came off easily. FWIW the O-ring simply looked dry, with no signs of dried/caked grease (as I mentioned before it had been put away using the correct Nikonos grease). Anyway this is the method that worked for my camera.

 

[reddesert]

Thanks for taking and posting the photos. They pretty well demonstrate how the thing attaches and seals. As a note I observe that your camera, a Nikonos III, seems to have a removable "lens cup," I will call it (I have no idea the proper name) on the body shell. On my Nikonos II this is a built-in part of the body casting.

The extra lens mount ring part in the NIkonos III is discussed at length on the archived version of the southern-nikonos site here: https://web.archive.org/web/2018090...om/WorkShop/Nikonos-III/WPCasing/wpcasing.htm

I don't think there's an obvious piece of metal that can jam the rotation of the lens. I do think it's plausible that it's just a combination of O-ring, dried up O-ring and grease, and corrosion. For ex, on my Nikonos II, the lens rotates easily. But the body is quite difficult to lift from the body shell, even though the O-ring of that joint is clean and greased. It's just really tight, because of the need to make a waterproof joint. You're supposed to lever the body up with the strap lugs, but it's not uncommon to see a used camera with broken strap lugs or body "ears," because of how tight the joint can get.

The apparently jammed shutter is a concern. It should fire without film. OP, just to be sure, it works differently than most cameras: the wind lever pops out forward. You move the shutter lock out of the way, and push the lever toward the body to wind and cock the shutter. Then you push the wind lever in a second time to fire the shutter. I think the I, II, and III all work that way.

 

[Mr Bill]

The extra lens mount ring part in the NIkonos III is discussed at length on the archived version of the southern-nikonos site

Hey, thanks. Interesting article (I like the way the author thinks). Back in the day I didn't have that much interest in the mechanics, etc., it was just a tool to get some photos. But after renting one I realized I could own one for the cost of a dozen rentals. So...

 

[fabulousrice]

No solution I tried worked so I ended up removing the top notch with a drill (I wish it didn't come to this... but I didn't see any other option). It's just a tiny hole and barely noticeable.

I wasn't too surprised to find a lot of corrosion inside the camera, along with sand in several areas. The rubber joints were not particularly damaged but several parts of the camera were oxidized. I had to scrub and clean a lot until I was able to fire the shutter, unfortunately the corrosion of the body and some parts of the camera may mean it will never fully work as intended again (I was surprised to find a totally rusted spring in the mechanism - and wondered if rust-resistant springs are a recent technology that didn't exist back when the camera was built).

After lubricating some parts of the mechanism, I am able to fire the camera almost normally although the aperture speeds wheel doesn't change the speeds. It doesn't help that when trying to unscrew the bottom plate of the camera, the bottom screws turned to mush which prevented me from going further in this project.
I might try to run a roll through the camera and use it as a side camera in dry situations or light rain (the top rewind knob came off and although I have it I am not sure how to reattach it... which makes the camera have a hole on top as well...)

 

[BrianShaw]

Sounds like a goner, but a fun camera for experimenting.

 

[fabulousrice]

Sounds like a goner, but a fun camera for experimenting.

For sure. It's kind of sad that these cameras were unintentionally designed in such a way that age will make it impossible to open them... (when the o-rings start expanding or decaying). I will definitely try to shoot with it without any O rings - might get some fun light leaks.

 

[Mr Bill]

Good show getting it open, but too bad about the corrosion. I wonder if a previous owner got flooded with seawater and decided it wasn't worth dealing with. (I don't know how else to explain the corrosion inside of a sealed chamber.)

I'm curious if the bayonet mount on the rear of the lens is seized up; if so this might explain why you couldn't get the lens pin to move enough to clear the notch in the body. (See 1st paragraph, my post #33.)

FWIW I think there may be a repair manual available on that site, "learncamerarepair". If so it would likely show details of the rewind knobs.

 

[blee1996]

Although I like Nikonos V for its modern handling, I really adore the original Calypso-based Nikonos II/III for its aesthetics and simple operation. I took it with me to Tahiti and enjoyed the shots both above and below water. I hope eventually you will find a good one.

 

[Sirius Glass]

No solution I tried worked so I ended up removing the top notch with a drill (I wish it didn't come to this... but I didn't see any other option). It's just a tiny hole and barely noticeable.

I wasn't too surprised to find a lot of corrosion inside the camera, along with sand in several areas. The rubber joints were not particularly damaged but several parts of the camera were oxidized. I had to scrub and clean a lot until I was able to fire the shutter, unfortunately the corrosion of the body and some parts of the camera may mean it will never fully work as intended again (I was surprised to find a totally rusted spring in the mechanism - and wondered if rust-resistant springs are a recent technology that didn't exist back when the camera was built).

After lubricating some parts of the mechanism, I am able to fire the camera almost normally although the aperture speeds wheel doesn't change the speeds. It doesn't help that when trying to unscrew the bottom plate of the camera, the bottom screws turned to mush which prevented me from going further in this project.
I might try to run a roll through the camera and use it as a side camera in dry situations or light rain (the top rewind knob came off and although I have it I am not sure how to reattach it... which makes the camera have a hole on top as well...)

I am sorry that it did not the desired outcome you were looking for.