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

eriMansori

Senior Member
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

Senior Member
Nikon D600+Non-CPU Lens Lightmetering won’t work, nor the aperture change

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.

602c60a2329f81da29f10e8273208cf4.jpg
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Fred Kingston

Senior Member
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.
 
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eriMansori

Senior Member
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

Happily retired
Staff member
Super Mod
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.
 

Fred Kingston

Senior Member
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

Senior Member
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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Fred Kingston

Senior Member
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

Senior Member
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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Texas

Senior Member
Without the notch, won't the whole protruding lens ring damage the aperture sensing arm in the camera ? Maybe Nikon anticipated this and made it retract?
 

Marcel

Happily retired
Staff member
Super Mod
Without the notch, won't the whole protruding lens ring damage the aperture sensing arm in the camera ? Maybe Nikon anticipated this and made it retract?
the only Nikon that has that retracting lever is the DF. As a matter of fact, the Df is (I think) the only one that will take any Nikkor lens with the F mount.
 

Fred Kingston

Senior Member
https://www.nikonimgsupport.com/ni/NI_article?articleNo=000001497&lang=en_US

Here's a link that explains the differences... Like Marcel says, the DF has a retracting arm, the other cameras didn't... The DF is the only "current" camera that will use these lenses without modifying the lens...Nikon did supply new modified lens kits for a couple of years but hasn't supplied them now for a long time. They used to be available for some on eBay for a while but even those have now pretty much disappeared...

Send Don White an email to the link I posted earlier if you have one of these lenses... I love my 55mm f1.2 on my D600...
 

Bob Blaylock

Senior Member
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.

The OP explicitly said that his 50mm was “AI-converted”. But I find myself doubting that, based on the pictures of it. A true AI or fully-AI-converted lens would have a second row of aperture numbers farther back on the aperture ring, and his pictures do not show that second row of numbers. That could very well be his problem. I have almost the exact same lens, but based on the serial numbers, mine is a slightly newer version than his. The second row of numbers really doesn't matter; the part that matters is a notch to be cut in the aperture ring. If the OP doesn't want to send his lens off to be professionally modified, and he's feeling brave, he might google “DIY AI conversion”, and see if he's up to trying to cut that notch himself.


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.

1536e2c34c79d888c620f07b3b4c8f90.jpg
d5e6eec02239ca6a94c69ccf0c9f977d.jpg
58baa1998df57193e335b137fc92916a.jpg
3231b12c811a2772c5115e165659a2de.jpg
bc11b081cb978f4d7b844b5a40d5906e.jpg
ea7195be3c43da054ed095154f218637.jpg



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jmishal

New member
I've exactly same issue
I'm also use D600 as well as nikon prime 50mm 1.4 and facing same problem.
I've try for almost all attempts with no successful
any suggestion?
 

eriMansori

Senior Member
I've exactly same issue
I'm also use D600 as well as nikon prime 50mm 1.4 and facing same problem.
I've try for almost all attempts with no successful
any suggestion?


I got a solution, but you have to sacrifice the lightmeter (doesn’t mean broke it) it just didn’t work because that classic lens doesn’t have an electric/digital notch for digital camera, it mount pretty well, all i’ve done to make the aperture works is to slightly loosen the lens but be careful, make sure the lens still safely attached to the camera, i loosen the lens around 1/3 before it clicks for lock, just take a look at the lens aperture when you’re doing it, set it at the smallest aperture so you can see the indicator by mounting that lens


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