Any differences between 24mm AI, AIs etc.

I've heard lots of good things about the 24mm F2.8 and am very close to buying

one, but I have a question regarding the configurations, which there seems to

be no shortage of... I really like the retro look of the scalloped focus ring

AI lens, which I think there are a couple variants of this particular series

i.e.: N, NC, and then there are the AIs version(s). Are there any major

differences in coatings or optical formula? I really like a lens with good

damping and have heard that the AI versions may be a bit stiffer to turn

(which I like). Thanks for any insight you might have.

Anything with a scalloped focusing ring would be <b>non</b>-AI unless it has been converted (either with a factory AI ring or independent modification). Unless these have been converted, they should NOT be mounted on an AI body such as the FE2.<P>

The AI and AIS versions (as well as the AF-D) have identical 9/9 optical formulas. You likely won't notice much difference in multicoatings. The N and NC non-AI versions (and last K version, which looks similar to the AI) have a different 9/7 optical formula, and different coatings. See <a href="http://www.photosynthesis.co.nz/nikon/lenses.html#24">here</a>.<P>

I only have personal experience with the AIS version.

I had the non AI version (when they were new) which got me hooked on 24mm focal length. I still have an ai version for my F3 and FM.

Thanks for the quick replies. This is the lens in particular I am considering. Normally KEH would advertise it as being AI'd if it was modified (not that it really matters to me unless it was a hack job). Maybe there was a missing link between the older scalloped non-AI and the more modern looking AI and AIs lenses?

The image shows a pre-AI lens. Nikon introduced AI in 1977. A year later, I bought a new AI 24mm/f2.8 and it looks like the one described on this site:

http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/24mmnikkor/24mmf28.htm

Shun, thanks for the link. Sorry the last picture was a bmp and should have been jpeg. Here's another of one I bid on recently where it clearly looks to be a factory AI with the scalloped focus ring and appears similar to the picture KEH is showing. Am I missing something?<div></div>

Donald, the images you are showing are lenses that have apparently been modified (AI'ed) afterwards. When Nikon introduced AI in 1977, they also modified the external design to use a rubber "O-ring" around the focusing ring, as shown in the link I posted above.

Those are factory AI conversions. Consider them as AI for all practical purposes. KEH classes their factory AI converted lenses as "AI" in their listings, rather than "AI-ed" (which they reserve for describing 3rd party conversions).

So did the optical formula change pre AI to AI to AIS?

Michael already explained that the pre-AI version is optically different. From AI, AI-S, AF to AF-D, the optically formula has not changed, but some people feel that the MF versions are better.

 

I had the AI and now AF-D, but I never had them at the same time.

Bjorn Rorslett's <a href="http://www.naturfotograf.com/lens_wide.html">evaluation of the 24/2.8</a> might be helpful to you:<br><br>

<i>"Nikon released its major achievement, CRC (Close Range Correction) with this lens in 1968 and it got a well-deserved popularity in the years afterwards. There have been a number of versions of this 24 mm lens, the first without multi-coating and f/16 as minimum aperture, the next multi-coated but still f/16, and the later versions (AI, AIS) going to f/22. Nikon has made several changes to the optical formula during the long life-span of this lens, which still is on Nikon's price list. Earlier versions flared less easily, but could produce quite visible ghosting when employed under strongly backlit situations. Newer versions flare more easily, but the resistance to ghosting has improved provided the lens is well stopped down. It gives very sharp images corner-to-corner even at the near limit thanks to CRC, but beware of field curvature if you are shooting perfectly flat subjects at close range. Some light fall-off towards the corners is evident at f/2.8 and gone by f/4-f/5.6. Set the lens to f/5.6-f/11 to get the best picture quality, but do not stop down to f/22 unless absolutely necessary. It provides excellent results when an ultra-thin K1 ring is added, and gives good results with a 4T close-up lens if some corner softness is accepted. The 24/2.8 MF Nikkor is a classic lens in the Nikon line and one that remains a dependable workhorse to this day."</i><P>

There is also a wealth of information here: <a href="http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/24mmnikkor/index.htm">http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/24mmnikkor/index.htm</a>

I have a 24mm that appears to be a late K series with a factory AI ring, with the older optical

formula. I got it new in box, with Nikon papers clearly showing the older formula, yet it is

undeniably a factory Ai ring conversion. So, not all Ai versions were newer formula.

Some K lenses with AI conversion look very similar to early AI lenses but you can go to several websites to look up the serial numbers if you are in doubt.

The earlier formula was largly mono coated(visible as magenta, blue and sometimes yellow

reflactions in the glass), then they added multi coating(multi shows lots of green reflections

in this particular formula). Multi version has better color transmission.

Christiaan: What you have is a very late pre-AI version that's been converted. An actual AI lens would have the new optical formula and be almost identical, the only difference being the presence of the maximum aperture indexing post inside the lens mount.

 

K and AI lenses are cosmetically identical if the K lens has a factory AI conversion ring on it.