Nikkor 24mm f/2.8 Ai-S Repair!!!

[richardHaw]

https://richardhaw.com/2020/01/04/repair-nikkor-24mm-f-2-8-ai-s/

happy 2020 everyone

[Roland Vink]

The Nikkor 24mm f/2.8 Ai-S debuted in 1981 to replace the aging design that was pioneered by the then-ground-breaking Nikkor-N 24mm f/2.8 Auto. The optical design didn’t change from that point until this lens came about.

Great article as always! A minor correction: the optics of the Nikkor-N 24mm 1:2:8 has 9 elements in 7 groups, it was the first lens with close range correction (floating elements) to give improved performance at close range and infinity. The Nikkor-N.C (with multicoating) and New Nikkor (modern barrel design) have the same optics. The AI 24/2.8 from 1977 already has the new optical design with 9 elements in 9 groups, also with CRC. The same optics were then used in the AI-S, AF and AF-D versions

[mxbianco]

I have the Nikkor N.C non-AI version (late serial 405xxx), and there are two more differences:

• Smallest aperture is f:16 (vs f:22 of the AI/AIs)
• Iris has 6 blades (AI/AIs versions have 7)

My sample has not been AI converted, I could mount it with no effort in the FTZ adapter of my Z6. The rear flange is nice enough not to obstruct mounting in any way.

Tried a few photos, quality is very good, focussing these lenses on a Z6 is a charm

Unless they build an FTZ-2 with an aperture feeler, there is no current need for me to convert this lens to AI. Maybe chipping it (easy), so I don't forget to change lens type in the non-CPU menu.

Ciao from Massimo

[richardHaw]

Great article as always! A minor correction: the optics of the Nikkor-N 24mm 1:2:8 has 9 elements in 7 groups, it was the first lens with close range correction (floating elements) to give improved performance at close range and infinity. The Nikkor-N.C (with multicoating) and New Nikkor (modern barrel design) have the same optics. The AI 24/2.8 from 1977 already has the new optical design with 9 elements in 9 groups, also with CRC. The same optics were then used in the AI-S, AF and AF-D versions

Thanks, chief!

I will correct it now!

[richardHaw]

I have the Nikkor N.C non-AI version (late serial 405xxx), and there are two more differences:

• Smallest aperture is f:16 (vs f:22 of the AI/AIs)
• Iris has 6 blades (AI/AIs versions have 7)

My sample has not been AI converted, I could mount it with no effort in the FTZ adapter of my Z6. The rear flange is nice enough not to obstruct mounting in any way.

Tried a few photos, quality is very good, focussing these lenses on a Z6 is a charm

Unless they build an FTZ-2 with an aperture feeler, there is no current need for me to convert this lens to AI. Maybe chipping it (easy), so I don't forget to change lens type in the non-CPU menu.

Ciao from Massimo

the non-Ai one has smoother focus transition

this one has better contrast but it loses the vintage feel

[John Geerts]

Thanks for the review and your repair-details, Richard. 

This is shot with the Nikkor 24mm f/2.8 NC version.  The old one, with some multi-coating   (also posted in January 2020)

[Tristin]

Your work will prove invaluable for decades to come Richard.  Many thanks.

[richardHaw]

Thanks for the review and your repair-details, Richard. 

This is shot with the Nikkor 24mm f/2.8 NC version.  The old one, with some multi-coating   (also posted in January 2020)

The old one is nice but the Ai-S gives me more contrasty photos which i like but if i want smoother tones, the older one is better

[richardHaw]

Your work will prove invaluable for decades to come Richard.  Many thanks.

thank you! i wonder if i can publish books

but whats the point? people can see my stuff online and it will be hard to edit my things

[golunvolo]

Your work will prove invaluable for decades to come Richard.  Many thanks.

Echoing Tristin. Fantastic work as usual. Most generous.
  Thanks a lot for sharing it

[Erik Lund]

Wonderful resource Rick! Thank you
For those who want more there is also a lot on the 24mm f/2.8 on the Mir site:
https://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/AFNikkor/AF24mm/index.htm

The images of the CRC part is difficult to see clearly, would be nice to see one day

[Tristin]

thank you! i wonder if i can publish books

but whats the point? people can see my stuff online and it will be hard to edit my things

That would be fantastic!  Though I would perhaps wait until you felt you covered Ai/Ai-s to a comfortable enough degree to make it really count.  In fact, I think you publishing a book on the matter is such a good idea, that I urge you to create a thread listing the lenses you can cover in such a book, and solicit opinions on lenses that should be covered that you haven't.  I  have a feeling that the good souls of NikonGear would be willing to help you fill in the niches in order to make this happen.  I would sign up to purchase such a book tomorrow, it would prove an absolutely priceless resource for Nikkor lovers for many decades, or centuries if you went for hardcover.

Keep in mind, "the internet is forever" is a very short-sighted view.  Please do put your knowledge to material record.  I wish I had more than my measly Ai/Ai-s "collection" to help you in this regard.

[Ihmemies]

For whatever reason I was not able to unscrew the set screw from focus ring front part. Even alcohol did not help with my lenses. Maybe patience would have helped.

I had the same problem with 24/2.8 Ai and 24/2 Ai-S.. so I just drilled the screw away and used tape when assembling the lenses. Does the same job.. now both lenses have an extra hole inside.

Thanks for the instructions, they are very helpful. I use mostly JHT #10 for helicoids, #30 sometimes for some sliding parts. Some Nikon autofocus lens grease for floating elements. FH-4 or whatever it was called. It has no "dampening" features like the JHT greases so it seems to work fine for that purpose.

[richardHaw]

For whatever reason I was not able to unscrew the set screw from focus ring front part. Even alcohol did not help with my lenses. Maybe patience would have helped.

I had the same problem with 24/2.8 Ai and 24/2 Ai-S.. so I just drilled the screw away and used tape when assembling the lenses. Does the same job.. now both lenses have an extra hole inside.

Thanks for the instructions, they are very helpful. I use mostly JHT #10 for helicoids, #30 sometimes for some sliding parts. Some Nikon autofocus lens grease for floating elements. FH-4 or whatever it was called. It has no "dampening" features like the JHT greases so it seems to work fine for that purpose.

yikes! maybe the drivers didnt fit? be sure to press on the screws to add stability

[Erik Lund]

For the small set screws it's very important to have a screwdriver tip that fits perfectly.
Hollow ground is the best way to go also for all other flat screws on lenses - I grind the myself from a slight oversize one.
Gunsmiths use them as well.
Precision hollow ground is the strongest!