Non-CPU Lens Lightmetering wont‘t work nor the aperture changes

**eriMansori** · 01-13-2019, 01:46 PM

So, last month i bought a Nikon D600, because i already have a pair of nikkor lenses that i used for my film camera, then i chose to buy a Nikon DSLR, one is a 50mm F/1.4 Ai-Converted and the other one is 28-85mm Ai Vario Lens, i‘ve searched and learn about how to use non-cpu lens on a digital one, and all they‘re works correctly in Manual mode, such as correct lightmetering, aperture changing indicator, but once i put my lenses on this D600, (1) i can’t put the lens to be fully locked, because when i pull the lens until it "clicks“ i can’t change the mechanic aperture of the lens, so all i can do is just loosening the lens, maybe 1/3 of it. It’s okay, i can handle the locking issue but the real problem is, (2) why the lightmeter doesn’t work? Does anybody here have encountered this kind of issue? I need your help guys, it’s really wasting my time. Oh, and I already set non cpu lenses data on the camera, I‘ll show you the pictures below.

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**eriMansori** · 01-13-2019, 01:54 PM

So, last month i bought a Nikon D600, because i already have a pair of nikkor lenses that i used for my film camera, then i chose to buy a Nikon DSLR, one is a 50mm F/1.4 Ai-Converted and the other one is 28-85mm Ai Vario Lens, i‘ve searched and learn about how to use non-cpu lens on a digital one, and all they‘re works correctly in Manual mode, such as correct lightmetering, aperture changing indicator, but once i put my lenses on this D600, (1) i can’t put the lens to be fully locked, because when i pull the lens until it "clicks“ i can’t change the mechanic aperture of the lens, so all i can do is just loosening the lens, maybe 1/3 of it. It’s okay, i can handle the locking issue but the real problem is, (2) why the lightmeter doesn’t work? Does anybody here have encountered this kind of issue? I need your help guys, it’s really wasting my time. Oh, and I already set non cpu lenses data on the camera, I‘ll show you the pictures below.

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**FredKingston** · 01-13-2019, 03:05 PM

The AI lenses won't work with your camera without modification. Basically, the mount doesn't fully engage and doesn't allow the aperture to function. Nikon sold adaptors to modify those lenses but no longer sells them, and unless a mechanic bought up someone's inventory many years ago, they don't exist. There were/are one or two older machinists that can modify the lens to work... It costs about $50/lens to get modified, including the shipping... Probably not worth it... If you google "AI Lens Conversion" you might find one.

AI Conversions for Nikon Lenses: Effective, Fast and Affordable! Here's John White's page. He's modified a couple for me over the years.

**eriMansori** · 01-13-2019, 03:11 PM

Originally Posted by FredKingston

The AI lenses won't work with your camera without modification. Basically, the mount doesn't fully engage and doesn't allow the aperture to function. Nikon sold adaptors to modify those lenses but no longer sells them, and unless a mechanic bought up someone's inventory many years ago, they don't exist. There were/are one or two older machinists that can modify the lens to work... It costs about $50/lens to get modified, including the shipping... Probably not worth it... If you google "AI Lens Conversion" you might find one.

AI Conversions for Nikon Lenses: Effective, Fast and Affordable! Here's John White's page. He's modified a couple for me over the years.

Ahh Thank You so much for the information sir, really appreciate it. Have a good day!

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**Marcel** · 01-13-2019, 03:51 PM

There is something in the camera's menu to allow changing the aperture with the actual aperture ring OR the sub command dial. Check it out. I don't remember exactly how it worked on my D600, but I remember having to enable this before my aperture would change. Hope this helps.

**FredKingston** · 01-13-2019, 03:56 PM

Originally Posted by Marcel

There is something in the camera's menu to allow changing the aperture with the actual aperture ring OR the sub command dial. Check it out. I don't remember exactly how it worked on my D600, but I remember having to enable this before my aperture would change. Hope this helps.

No... That doesn't apply to these lenses...In fact, as he mentions, the lens won't even click-lock in the bayonet mount and, and I wouldn't encourage forcing it because it will damage the aperture mechanism in the lens and could lock the lens onto the camera's body...

**eriMansori** · 01-13-2019, 04:01 PM

Originally Posted by FredKingston

No... That doesn't apply to these lenses...In fact, as he mentions, the lens won't even click-lock in the bayonet mount and, and I wouldn't encourage forcing it because it will damage the aperture mechanism in the lens and could lock the lens onto the camera's body...

It can click-lock but the aperture always stays at its largest aperture, and yes, i‘ve heart something when i put it on for the first time, it sounds like something blocking it but i forced it to get in, fortunately nothing damaged. Since then i put the lens really carefully.

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**FredKingston** · 01-13-2019, 04:09 PM

There IS something blocking it, There's a notch that needs to be machined into the lens mount so it engages with the camera correctly...Once the lens has been modified, it will click-lock smoothly and the camera will be able to operate the aperture... All Nikon lenses stay wide open until the camera shutter fires and then closes the lens Down to the correct aperture opening...

You would follow Marcel's advice regarding non-CPU lenses after the lens is modified. Right now, there's a physical mechanical problem preventing that from working.

**eriMansori** · 01-13-2019, 04:24 PM

Originally Posted by FredKingston

There IS something blocking it, There's a notch that needs to be machined into the lens mount so it engages with the camera correctly...Once the lens has been modified, it will click-lock smoothly and the camera will be able to operate the aperture... All Nikon lenses stay wide open until the camera shutter fires and then closes the lens Down to the correct aperture opening...

You would follow Marcel's advice regarding non-CPU lenses after the lens is modified. Right now, there's a physical mechanical problem preventing that from working.

Alright, i see it clearly now, once again, Thanks Fred!

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