Is it a pre-AI, an AI or an AIS lens? How to tell.

Have you ever been confused with the different generations of Nikkor manual lenses?
Becky Danese explains how to differentiate....she knows stuff.
Video Production: Foteini Tasiopoulou
In the video (from our second-hand department):
50mm f/1.4 pre-AI: bit.ly/50mm_preAI
28mm f/3.5 AI'd
50mm f/2 AI:
50mm f/1.4 AIS: bit.ly/50mm_f1...
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[@bengt_axle]

For anyone asking, second row of small aperture numbers were to enable the user to see the aperture through a window in the viewfinder of the camera. That way you could see exposure and aperture without having to move your eye from the viewfinder.

[@AndyHayter]

Best and simplest explanation I have ever heard, Thanks Becky!

[@graysofwestminster]

Very glad to hear it, Andy - thank you! :)

[@TheGreatLoco]

What I have read, one big and important difference is that AI-S lenses the aperture pin moves in exact same distance from one aperture to another, where in previous versions that’s not the case and could give an under or overexposed picture. Btw, Nikon Df can use pre-AI, AI, AI-S and the AI-P manual lenses that are missing in this review. Nikon produced just 3 AI-P lenses, like the 45mm 2.8 AI-P, the 500mm 4.0 AI-P and I think the exotic zoom 1200-1700mm 5.6-8.0 AI-P. However, Zeiss still makes AI-P lenses, called ZF.2. Voigtländer lenses for Nikon, like the Nokton 58mm 1.4 SL II S, are also AI-P. One can adapt an AI-S lens with a Dandelion CPU for full AI-P functionality.

[@toulcaz31]

Great to see you on KZbin guys. Don't be shy to do videos on film cameras too. There is a big analog crowd out there.

[@anthonydavis4829]

Direct and to the point. Great video with examples. Best video on the web at explaining this.

[@ColinOYoung]

Thanks. I remember buying a camera body at Grays in the mid 80s. Very alluring shop. Haven't had a chance to visit since, unfortunately.

[@graysofwestminster]

It'd be a pleasure to have you visit us again!

[@michaelmalodrums9674]

Maybe also important to point out if it wasn’t clear is that with the Ais lenses you can control the aperture in camera where as with the Ai versions you have to set your aperture on the lens itself .

[@marysanchez4789]

Such a detailed explanation, thanks! I'm subscribed now 😀 Is there a way to spot when these lenses are SIC versions?

[@henryIRL]

Great video! I’m curious, optically, is there a difference between non-AI, AI and AI-S lenses?

[@tomheckhaus7617]

Very well done. I'd like to add a little more trivia. The "ears" have little holes in them, why? The second aperture ring with the tiny numbers can be viewed through most cameras in the viewfinder. The little holes usually at f8 and f4 are there so light can illuminate those f stops and not cast a shadow.

[@graysofwestminster]

That is simply amazing. Thank you for sharing!

[@terrygoyan]

Good point. The second set of aperture numbers are called by Nikon, ADR. An acronym for Aperture Direct Readout. And yes, they were added so the aperture setting can be seen in the viewfinder.

[@henrysteadman963]

I have a few older manual Nikkor lenses (superb!) varying in date and all are Ai compliant, however this is extremely clear and really useful to have clarified in this way from such a trusted source as Grays as I was recently wondering about a non-AI optic and actually this would have needed updating although I wonder whether there are adapters that WORK with non-AI lenses? I hope you’re all doing well in Grays in these tricky circumstances, all the best to Pimlico :)

[@graysofwestminster]

No specific adapters but you could use an extension tube as a way around it potentially! Thanks so much, Henry :)

[@were2man]

Hi Becky, Can use the Ais lens on mft Olympus omd cameras? If yes, any recommended manual adapter to fits them together? Thank you

[@graysofwestminster]

Hi Joshua! I'm pretty sure that Fotodiox do an adapter for these :)

[@sman222222]

Very well explained. I have a pre ai Nikkor - S 35mm f2.8. Which camera body would work with the pre AI mount?

[@pakko7416]

Excellent video, concise and to the point! Thank you!!!

[@amermeleitor]

Is this relevant if I want to adapt old manual Nikon lenses to my Sony a6000? Or the adapters are compatible with all old F mount Nikon lenses?

[@graysofwestminster]

It rather depends on the adapter, but generally if the adapter is a plain F mount (with no ridges to utilise the notched aperture ring on AI and AIS) then yes, it should work.

[@mikaelkijbunchoo667]

Hi, I love your videos. Everything is informative and easy to understand. However, I still have a confusion over one specific thing concerning lens compatibility. I own the 50mm f 1.8 ai-s (pancake lens) and my friend is offering me his Nikon F2. As the lens is ai-s, but it does not have a prong, will it work with the earlier version of F2 (eg. F2 with dp-1 to dp-3 prisms), or it is only going to be compatible with F2A and F2AS? (ps I do not wish to use stop down metering) Thank you for your reply in advance. Cheers!

[@graysofwestminster]

Hi Mikael, Thank you for the wonderful feedback! You will need a prong for compatibility with the F2 and F2S but as you suspected you'll be fine with the FTA/F2AS cameras as they don't require the AIS prong.

[@srfurley]

With a body which does use the ai-s feature can you confirm that it makes no difference at all whether a ai or ai-s lens is mounted when the camera is used in aperture priority or manual modes, but only when used in shutter priority or program modes? I haven’t done any photography in about ten years, mainly due to failing eyesight but still collect cameras. I have recently taken my cameras out of store and am going to try to use them again following some treatment which has somewhat improved my eyesight. I have one AF Nikon body, but have never owned an AF lens. I am mainly interested in the older cameras. I was going to go to Photographically to try to buy an AF lens, but presumably it will not now take place this year. What are the differences between af and af-d series lenses? Have lots of manual ficus Nikon bodies, F, FM, FE, FG, EM, F301, all in very good condition but bought cheaply over the years.

[@sclogse1]

A perfect presentation.

[@RedHell2884]

Regarding the three types, how do I know which Nikon camera is suitable for it, or can I use it with it?

[@3shibuyallc486]

Great video! Which version of these lenses are considered to be the best or more sought after? I have an 85mm F1.8 pre AI and I love it! It is one of my favorite lenses in my collection.

[@graysofwestminster]

Totally! The 85mm f/1.8 is definitely one, along with the 55mm f/1.2 and the 105mm f/2.5 pre-AI (or AI or AIS actually) - all are considered sought after lenses, but there are some real gems throughout the range to be honest :)

[@elise3455]

Thank you! I was so confused when others tried to explain the differences! Now I can confidently purchase an Ai or Ai-S without fearing that it won't fit :D

[@willford8475]

My head hurts, I'm going to have to lie down after that! Thanks.

[@DidierMOULINPhotography]

Very simple ! Thanks a lot As far as I know, some camera can work with pre AI as well as with Ai and Ais. Nikon F4 Nikkormat FT3 Nikon DF AM I wrong?

[@jonathanphilips3760]

A couple of things - 1.Needed to mention the notch in the aperture ring is not for aperture setting from the camera. 2. What AIS stands for ? viz. Aperture/Auto Indexing Shutter. And why they are called so ? And the reason for having them ? That ways it would help in remembering things too ! ;)

[@charliejeong839]

Thanks for the great video. Any difference of image quality between Non AI and AI and AIS ?

[@Warrior_Resisting_Colonialism]

As a general rule; no. However, you would have to research the individual lens to know for sure. For example I was doing some research I learned the earlier version of the 400mm 5.6 takes sharper photos.... and they didn't even make AIS options. Just earlier and latter version of IA (they made 3 different copies in total) so you really have to spend some time researching vintage lenses to learn how many different copies they made and which one might be best and which one might be worth saving a few bucks on. I saw some flickr photos where two users were posting photos with the "400 5.6 ia" and based on one users photos I wouldn't even want to buy the lens! The others photos, are tack sharp and it looks like a fantastic lens! No mention of which of the 3 they have but based on research I concluded one is using a newer version and one, the older. In this case, I'd only buy the older version........ it seems to be more pricey than a modern 80-400 w/ VR and what looks to produce better photos than all 3 of the old primes anyway lol.

[@gilgemash]

I do like your desk. It's lovely, old wood. Precious. Thanks for your commentary. I have a nikon 135/3.5 pre ai lens, which I'd like converted, so can use on d810 etcetera...to no avail, so far. 🙁

[@elizabethwilfong2260]

Super useful! Thank you, I finally know which lens I have. I will check out your channel to see if you have information regarding adapters for Sony cameras to use Nikon lenses.

[@Kenquist]

Hello, for the Pre AI. When you say the won’t work on modern cameras. Don’t you mean they will mount, you can use them in full manual mode only. Yes? They just won’t auto focus, or meter.

[@graysofwestminster]

Actually it isn't recommended to even mount pre-AI lenses onto AI cameras, unless the Aperture Indexing lever can be moved out of the way. A pre-AI lens mount can damage both AI lever on the camera and, in some cases, the CPU contacts on the camera. So unless you are confident that neither will be interfered with by your lens it is best to avoid it! But yes, potentially you could use it in full manual mode with no metering if you were certain it would be safe. Hope that helps!

[@soundstorm]

exceptions 3400 3300 3200

[@KanonMadness]

is there an adapter ring or something to avoid doing the whole cutting thing and be able to use it with new Dslrs like the D850?

[@graysofwestminster]

You could use an AI/AIS extension ring, which would affect the close focusing distance, but there's no specific adapter sadly.

[@jonneville2287]

Apparently, there is also a difference in focus throw between the Ai and Ais series - I think the Ais lenses had a shorter throw, but this may not apply to all lenses in the series.

[@paganphil100]

Jon Neville: Some sources say that the "S" in AIS stands for "Short focus throw".

[@twisterwiper]

Excellent video - very helpful. Thanks!

[@alexparson4472]

Very nicely made and apt information. Great job.

[@passionfruitestate9691]

Well done. Helpful as I re-acquired an Nikkor lens from SIL. Turns out it is an AI-S. Thank you.

[@kohutracing]

Really a great informative video!! I learned the diffrence thanx

[@robertjpayne]

Thank you - I bought a 28mm vintage Vivitar lens from fleabay which said it was a Pentax mount but it so didnt fit. Your very helpful video has shown me it is an AI Nikon lens, but possibly altered from a pre AI barrel as it a 'N/AI' marked. But it does have the double set of aperture numbers and the notches on the mount you demonstrated. I wonder if it has any value to the Nikon community? Thanks again

[@abdoulazizngom2264]

Thanks very much for this great, simple and clear explanation, the difference is now much obvious to me! Keep up the good work.

[@joellemorris5684]

your video is very informative. thanks!! Based on few videos i watched, i understood that if we have non-AI lens mounted (via a speedbooster) on mirrorless camera like Panasonic GH5, we will not be able to read the aperture change in the viewfinder. Is that correct?

[@graysofwestminster]

Generally that's right - not many of the adapters (if any) will read the aperture change from a non-AI lens, but with the mirrorless cameras what you see is what you get so you can still judge exposure accurately :)

[@josecaffarena4269]

Thanks for all the information. Optically, which of the 3 generations has the best quality?

[@graysofwestminster]

Hi Jose, it does vary from lens to lens. Ultimately the AIS and AI tend to be similar, if not the same, in optical design for most focal lengths, while the older coatings on the pre-AI discolour over time and produce a slightly different cast. But it depends on what camera you're using and what sort of effect you're after as to which would work best for you. I'd suggest having a look at videos/blogs with the specific models for some real-life opinions if you're thinking of picking one of these up!

[@forkintherode8236]

You are very knowledgeable. I enjoyed this video very much, and what a wonderful camera store. Thank you

[@steinarkjrjohansen4400]

Finally I understood the difference. Thank you

[@marcwalsh]

wonderful video, thank you so much

[@MMPAspergerian]

Super useful Becky, thank you!!!

[@RedHell2884]

Genius video

[@danc2014]

The ais notch is not tbe black cut out but a cut in the metal above it

[@randypipper92]

So I can't use AI lens in Apperture priority mode on the Nikon F4 right?

[@paulcrawley7321]

Very well done, I have a few some bought from yourselves. Great lenses.

[@graysofwestminster]

Thanks, Paul! Glad to hear it.

[@michaelmitelman6004]

Great video. Makes it simple.

[@RedHell2884]

can I use AI or AIS with nikon dslr (Apsc or full frame)?

[@yanitsvetanov1162]

Do you know, or have got any information on the radioactivity of the old film era lenses? Thanks?

[@renoholland7090]

Very useful. Thank you.

[@ndnride295]

Wow! thank u for this been looking for it.

[@deltaforceaviation7924]

Hello, my name is Luis and I am an amateur photographer. I have a question about using Nikon "Pre/Non AI" lenses in digital cameras. I want to buy a "modern" Nikon camera that accepts my Nikon "Pre/Non" AI lenses and the Nikon DF is the only one, all the others of my interest (D700/D3x/D3x/D750) do not accept these lenses. I have some Pre/Non Lenses, with my collection of Nikon F and also, they are cheaper than AI and AI-s, not to mention Auto-Focus. But the Nikon DF is a very expensive camera, even used. Do you think it would be better for me to buy a cheaper camera, like the D700 and some more AI/AI's lenses, or invest a little more, buy a Nikon DF and abuse the good prices of these legacy lenses (Pre/Non)?

[@graysofwestminster]

Hi there Luis! I think the trade off has to be - is buying a Df going to be cheaper than paying to have your non-AI lenses converted? Depending on how many lenses you have, and assuming the cost is still in the region of $150 per conversion (but could be more), one will end up more cost effective than the other I think. The other way to consider it would be is the Df so much more expensive than replacing out your pre-AI lenses with AI/AIS versions? The Df is a superb camera and they do hold their value quite well considering they are 8 years old now, but ultimately converting your lenses to AI/AIS will future proof them in the long run.

[@deltaforceaviation7924]

@@graysofwestminster I'm grateful for your answer to my pretty complex message. My pictures are a challenge to me, especially because I'm a little stubborn with the subject, always insisting to do the thinghs the more complicated way. (avoiding the comfort zone) Today, I still have not photographed digitally yet. (I'm 55) Only film, but I feel it's time to merge to give more latitude. I'll go deeply on your advice and decide it later on, I still have a maturation period to go. Love your show Best Regards Luis

[@brianireland3554]

Brilliant explanation.

[@pixeldustisaiah]

I know all the physical differences between the lenses but what about glass differences? I have a Pre AI set and looking into an ais set

[@deepakramadasan4436]

Really great video, very informative. I do have a query though: I have a pre-AI 50mm f/1.4 lens - it mounts and functions on a D90 but would it work on a D700? Is there any kind of adaptor that I could use to make it work on a D700? Many thanks

[@graysofwestminster]

Sorry for missing this comment! If your lens is fitting the D90 then it should technically fit the D700, but there's always a risk of damaging the plastic aperture coupling prong with either camera. Proceed with caution :)

[@deepakramadasan4436]

@@graysofwestminster Hi, I decided not to attempt fitting it on the D700. I dont own the D700 anymore and I now have a pre-AI 50mm f/1.4 lens that I dont know what to do with. Is there a market for such lenses? Thanks.

[@Cotictimmy]

Great stuff. Quick Question: Can you damage a digital body by mounting a Pre-Ai on it? It looks like 'no' but I seem to remember hearing somewhere that it could cause damage to a digital (maybe foul electrical contacts?) Also - I'd love to hear you expand a little more of the function of the Ai-s notch and its interaction with "certain cameras". Timmee on PP.

[@graysofwestminster]

Thanks for your feedback! Pre-AI lenses can actually get stuck on digital bodies so it is best not to mount them. The aperture coupling lever that sits at the 1'o'clock position around the mount of the camera can also be damaged while mounting a pre-AI lens so we wouldn't recommend attempting it. The AIS 'notch' in the back of the lens is only adopted fully by two cameras - the Nikon FA and F-501. There are other bodies that made some use of it, but these two are the only bodies that required the notch to be able to accurately stop down the lens to the required aperture in shutter priority and program modes. Hope that helps!

[@Cotictimmy]

@@graysofwestminster Yes - very useful indeed. Thank You. BTW the Matt Granger chat with Gray was wonderful (and Gray said you were good in during that interview LOL.) PS. I had a FA once upon a time but I found the FE & FE2 more pleasant to handle and use.

[@quananh3990]

will AI and AIs lenses work with Nikon F2 Photomic? Thanks

[@graysofwestminster]

Absolutely!

[@HarveyWallbanger-ho2cq]

You can just look at the indexing tab. It will have 1 hole or 3 holes

[@laurencemoss8049]

You could mention what cameras the lenses work on .

[@curtisgrindahl446]

I had five early manual focus lenses made by Nikon sitting on the desk in front of me and a Df camera on a cabinet to the side when this video showed up in my KZbin feed. I have a total of 46 Nikon lenses, half pre-AI, half AI and AI-s accumulated over the years. I haven't been shooting much during the COVID years and am pondering whether to head out today with the Df so I can take a few photos to post on a thread I started almost 13 years ago on Fred Miranda titled Manual Focus Nikon Glass. These amazing lenses are still a joy to use. I'll take this video as encouragement to take a few photos today. I'll likely shoot with the pre-AI 135 f/3.5 Q with the Nikon AI conversion kit installed and an HS-4 hood attached. It looks rather stunning on a silver Df and produces amazing images. I bought that lens in pristine condition, already converted with the lens hood for under $60. What a pleasure this hobby is! This video will doubtless help newcomers sort out their questions. And remember, a K lens is a pre-AI lens.

[@gilgemash]

I too invested in a 135/3.5 q... Which I'd prefer to get converted, to use with d800/810... No luck, in a year. Maybe I'll get a reversing ring & use it for macro use. It's just sitting on a book shelf, frustratingly. 🧘

[@louiscyphre2555]

thanks for the video

[@m-focus]

Thank you !!! This helps

[@chuckalvarado8484]

Thank you for this video. I now know the difference 👍🏽👍🏽

[@scottmurphy650]

The Non-AI WILL fit on Nikon DSLR's without the aperture following ring around the lens mount and can meter in the stop down mode if the camera has a depth of field mode. Putting a Non-Ai Nikkor on a camera with the aperture follower will, however damage it, with the exception of the Df, which has the flip up follower like was found on the F3 and F4. The notch on the mount of AIS lenses is actually to key certain bodies like the F4, F5 and F6 to enable Matrix metering. It does not have anything to do with aperture settings.

[@graysofwestminster]

Indeed, aperture settings have nothing to do with it at all and you are quite right, non-AI will mount, but will damage the aperture coupling lever on cameras where it can't be moved out of the way. I did a handy video on stop-down metering for anyone interested!

[@joaoalves6729]

Neither the F5 or the F6 can detect the notch on the mounting flange of an AI-S lens. If the lens has no CPU, they will have no way to tell and won't make a distinction between AI and AI-S. The F4 doesn't need the lens to be AI-S to use matrix metering. There seems to be a lot of confusion around AI-S, it solely provides standardized aperture control. In cameras that can tell (FA, F4, F301, F501) it helps in S and P modes, and most probably taken into account to improve metering accuracy.

[@JP1050x]

Some Nikon AF mount cameras also have a second little switch that tells the camera the min aperture size. So, if the camera lacks the aperture feeler switch, you’d still need to look out for that secondary aperture switch or it can also break with an unmodified pre ai lens. Cameras with matrix metering will still meter with or without the notch at the mount surface. The notch is used for early cameras that can make use of shutter priority using non chipped manual lenses.

[@yahyaharyantoo]

very helpful, thank you!

[@lloydgarland4667]

Thank you!

[@JonnyEnglish-gu1cs]

Great video really useful 👍🏻

[@mpimpaophoto2075]

Excellent! Thank you!

[@lucasbarros5937]

Are these all the same optics?

[@gabrielebuffa2520]

Thank you, very easy, very useful :)

[@manostroulinos1726]

Excellent, many thanks, at last we see the light! :-) But why is Clint Eastwood/Robert Kincaid in focus and not Becky on the first part of the video? It seems the video camera has a mind of its own and prefers either film stars or NatGeo photographers :-p

[@graysofwestminster]

😅

[@humbledmfg]

Thank you!!!

[@jp3576]

Thank you, that was very helpful. I’ve noticed after some research and personal experience my non-AI nikkor works quite well in manual mode on a D3300 and have read non-AI will work on D3XXX-D5XXX. Just use ISO as shutter speed to your aperture setting. Works fine and simple to use. Thank you again.

[@graysofwestminster]

Some lenses certainly will fit, but others will jam on the little aperture indexing lever around the mount of the camera so you do have to be a bit careful. Hope that helps! :)

[@matt904sl]

Thanks so much for sharing the knowledge 👍👍👍👍👍 great video

[@35RAW]

Nice video. Thank you

[@slicer819]

Great stuff Becky, very informative. More of the same please!

[@graysofwestminster]

Excellent, so happy to hear it!

[@mistuhgee]

My question is, can you safely put AI and AI -S lenses on a D800?

[@marksieving7925]

Yes

[@Chivoyage]

Great review but focus is off on the wide shot (focus in on the wall).

[@donaldong3924]

Is it worth to buy the AI-S version of lenses? Why is that? Whats the purpose of the extra 'S'?

[@shudduptimmy3880]

Get the one which is better in condition. Its just cosmetic changes and shouldn’t give you no particular advantage over the other if you’re using it on the newer DSLR cameras

[@markpedwell1250]

Much appreciated 😊

[@Herzblut08]

Thank you so much

[@drrrw]

Optically, are there differences?

[@marksieving7925]

Sometimes. Some AI and AIS lenses used the same optical design as their predecessors. It other cases the optical design was changed when the indexing was updated.

[@RedHell2884]

which one can I use with nikon f mount (pre ai or ai or ais)

[@graysofwestminster]

Depends on the camera! Nikon F and F2, all of them. Later cameras AI or AIS are recommended.

[@RedHell2884]

@@graysofwestminster Thanks for the reply and the answer, but the topic is complicated and I am trying to understand it. Question: How many adapters do you think I need to be able to use any old Nikon lenses with DSLR cameras?

[@RedHell2884]

@@graysofwestminster Naturally, I must mention the importance of this video.

[@kunsunrethy]

THANK YOUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU!

[@vercohandel9818]

thanks!

[@paganphil100]

Any Info. on the "D" lenses?

[@marksieving7925]

D lenses are autofocus lenses with a chip that tells the camera the focus distance. This is relevant for TTL flash but otherwise doesn't matter. They will fit any Nikon camera but will only autofocus with cameras that have an autofocus motor in the body, since the lens doesn't have its own motor.

[@jaakkooksa5374]

What happens if you put a pre-ai lens on a modern Nikon body?

[@marksieving7925]

There's a tab on the body of the camera that engages the notch on the aperture ring of AI and AIS lenses and tells the camera what aperture is set on the lens. If you put a pre-AI lens on a modern camera it will damage this tab and the camera will no longer be able to identify the aperture on the lens. Early AI cameras like the FM let you fold this tab out of the way to mount pre-AI lenses, but the only modern Nikon camera that will do this is the Df.

[@randallstewart175]

While it isn't very important any more, as only a few bodies used the feature, her explanation of why the AI-s lenses have a notch cut into the based of the lens mount is totally wrong. The AI-s notch has nothing at all to do with the lens aperture or its setting on the body. The purpose of the notch is to inform the body meter whether the attached lens has a focal length less than 135mm or 135mm or more. Apparently, this effected how the TTL metering functioned. The bodies designed to use this feature have a small pin which protrudes from the front of the lens mount. If the lens has a notch, the pin remains in its normal position. If the lens has no notch, the pin is depressed when the lens is mounted, signalling the meter.

[@graysofwestminster]

Hello! You're not wrong there. For anyone interested, the Great Simon Stafford says, in his full and comprehensive explanation of the differences: Other features found on Ai-S type Nikkor lenses but which are absent from the Ai type include the following: A small semi-circular notch milled out of the lens mount bayonet flange, which indicates to the FA, F-301, F-501 and F4 camera models that an Ai-S type lens is attached. The minimum aperture on both the main and ADR aperture value scales is marked in a bright orange. On lenses with a focal length of 135mm or longer, the focal length indexing ridge, a flange that is located around the outside edge of the rear element, extends past the indentation in which the lens locking pin seats. Again this is used by the FA and F501 cameras to detect when a telephoto lens is attached in order that the camera body will select the appropriate option in the Dual-Program exposure mode; the camera automatically switches to P-Hi (high-speed Program) that sets a bias toward higher shutter speeds to reduce the effects of camera shake. When lenses with a focal length shorter than 135mm are attached to these cameras normal Program exposure mode is selected.

[@joaoalves6729]

There seems to be a naming confusion about what's the notch here. There is a gouge scooped out on the face on the mounting flange, and additionally, there is a focal length indexing ridge next to the back element. The indexing ridge conveys mechanically the information to the body, whether the lens is 135mm or over in focal length. The scooped gouge indicates that the lens has a standardized aperture control. Look at a close-up image of an FA or an F4 and you'll see where each one of them interacts with the body. The ridge interacts with a lever towards the centre, next to the lens retaining pin. The gouge interacts with a switch on the face of the flange, above the lens retaining pin (if the switch is depressed, the lens is not AI-S). Besides those, there is also a lens speed indexing post, that interacts in the body with a lever in the bottom of the mount. All these mechanical levers on Nikon bodies were phased out after the F4, with the introduction of the lens CPU.

[@joaoalves6729]

@@graysofwestminster What was called the notch in the video was the scooped gouge. It informs the camera that the lens is AI-S (Automatic Indexing - Standardized), so the movement of the aperture is linear (which is relevant for accurate metering and calculating exposure modes S and P). Thank you Grays of Westminster for all the effort in the making of your videos!

[@727jetjumper]

Beware of K type lenses, they look like Ai but are not. Check the serial number list on the Photosynthesis.co.nz website. (I experienced this with a 50mm 1.4)

[@p.h3813]

TERRIFIC - Very useful :) Thanks

[@AnickYT]

To clarify, all Nikon lens will physically fit and work on all Nikon DSLR. You simply won't have any auto features such as exposure or focus. You will need to be in full manual which I think you should be able to do as a photographer anyway.

[@graysofwestminster]

Yes and no. With some combinations of body and lens a Pre-AI lens will get physically stuck on the body as it will jam onto the aperture coupling lever that surrounds the mount. Because on digital cameras this is made of plastic (with the exception of the Df). So although in all the years of the Nikon F mount the design hasn't changed, there is a risk factor to mounting pre-AI lenses to DSLRs. Sometimes you can get away with it of course without damaging anything! Hope that helps :)

[@terrygoyan]

Not true at all......

[@erikleypoldt8275]

So what would be best for the F3?

[@graysofwestminster]

All three will work, but AI and AIS can be used without stop-down metering (we have a video for that too though if you fancy giving it a try!). The AIS are the right generation for the F3 if you want everything to be coeval :)

[@joaoalves6729]

​@@graysofwestminster Right generation? I don't fully agree... The F3 was released in 1980, about 2 years before the AI-S (Automatic Indexing - Standardized) was introduced. Any lens with Auto Index will work indistinguishably well on the F3, as it lacks the ability to sense if a lens mounted is in fact AI-S, and doesn't even matter, as the F3 doesn't have Shutter-Priority or Program modes requiring a standardized aperture control. If you look closely at the mounting flange of an FA, F4, F301 and F501, you'll see a small pin, sticking a little above the lens locking pin. It's a switch, depressing this will tell the camera that the lens mounted is not AI-S (hence the gouge scooped in AI-S lenses to avoid it). Nikon dropped this system shortly after (though the notch was kept), in favour of a CPU in the lens. Cameras that don't have the AI-S switch on the mounting flange, can't tell if a non-CPU lens is standardized or not, and won't take any benefit from it.

[@dcooper6857]

@@joaoalves6729 so ai versions are the best for F3s? can i still use ai & ais for digital slr, like for example d40x?

[@LondonViewpoints]

My 35mm f2.8 PC has only one row of aperture numbers but indeed the 2.8 on it is orange so I guess it’s AI-S ?

[@graysofwestminster]

Actually PC lenses are slightly different due to the double aperture control, but if yours has a black shift knob then it is AIS, but if it has the chrome shift knob it'll be AI or potentially even pre-AI

[@LondonViewpoints]

Grays of Westminster unfortunately silver, but it’s a phenomenally sharp lens nevertheless, so as it fits F mount fine I’m guessing it’s AI, thanks for your prompt reply🙏🏻

[@terrygoyan]

On AI-S lenses the orange color is on the smallest aperture setting, not the largest.

[@trevorker-lewis4399]

Thank you, that's perfectly explained. :)

[@graysofwestminster]

So glad that you found it helpful!

[@JP1050x]

Great video. Ai = aperture index. But the extra S (Ai-s) means “shutter,” which enables some Nikon cameras to use shutter priority with non chipped manual lenses. Sort of ironic, that the F mount was not fully compatible across bodies throughout the years. Staying with the F mount, made Nikon lose its competitive advantage…. and is trying to catch up with the new Z lenses.

[@faithinverity8523]

I like non-ai lenses on digital bodies. How weird is that?

[@Audimann]

Did Clint Eastwood commercials or something for Nikon? I only recall Clint advertising his 44 Magnum as the most powerfull handgun in the world😂

[@mark-davidchandler5895]

nailed it

[@abbycasanova1380]

pre ai lens can be converted to ai lens

[@marcelvanengen1307]

Nice explanation of differences between nikkor lens types. If you want your non-Ai lens professionally modified (almost invisible) have a look at magnimopus.com/services. Located in UK. Offers a much more elegant type of modification or conversion. Works for most non-Ai lenses and most types of Nikon cameras with metering tab.

[@graysofwestminster]

Thanks Marcel - what a great resource! Appreciate you sharing it with us :)