AI superior to AI-S?

[pluton]

The MIR site is plagued with more historic Nikon photos, and information, than any site I know of.

There are some inaccuracies, including typos, but it is a colossal effort that I am grateful someone took all that time to do.

It is easier to "point out the cracks" in a tremendous skyscraper ... than it is to build a better skyscraper

True, true.  It is a resource. 

[crazycaper2000]

Hi all I recently purchased the ai-s 200mm f/4 nikon lens and love it. I use the nikon d7100 and would like a little more reach of course[everyone does right]. I have found a kenko teleplus pro 300 dgx 1.4 teleconverter and was wondering if this is a good fit with the lens. Is this teleconverter too new and could I spend less on an older teleconverter and get the same results?

[Roland Vink]

The 200/4 with a 1.4x TC gives you a 280mm f/5.6 lens. The Kenko will probably fit the lens but I doubt the resulting combination perform well at full resolution on the D7100.

At this focal length and aperture I suspect you would be better off using a 70-300VR lens, where you get the benefit of VR as well.

[crazycaper2000]

ok thanks for the help.

[Steven Paulsen]

I will add what BR mentioned about Ai/Ais metering on my D800. The only minor bug is that my D800 sees my 105.f2.5 as 2.8. My D700 does the true 2.5 metering using the camera's ring.

[Roland Vink]

If you set the D800 CPU lens aperture = f/2.5 it should report the correct aperture wide open (unless the lens has an "unofficial" AI conversion and the AI cam isn't in quite the right place)

[Per Inge Oestmoen]

a simple and broad generalisation from me from a teardown point of view.

Ai:
tougher construction
heavier
more screws
Nikon loves using glues in this generation but not as much as the New-Nikkors
tough,traditional construction with the lens barrel and optics separated

Ai-S:
lighter
clever tricks used to simplify complicated assemblies
cost-cutting on some parts (plastics, scotch tapes, plenty of brass shims)
optics casing sometimes incorporated in the lens barrel as cost-cutting and making things more compact/simplification

I personally like fixing the older Nikkors compared to Ai-S ones. it's like fixing a beetle compared to a ford focus 

Not to shoot the messenger, but since the above is very interesting it would be great if you can elaborate a little more.

- If scotch tapes and plenty of brass shims are used, in which Ai-S  lenses have you observed this and where?

- As for plastics, do you have examples of plastic being used in Ai-S lenses in such a way - or with such types of plastic - that the sturdiness or longevity of the construction would suffer as a result?

- What would be the downsides of incorporating the optics assembly in the lens barrel?

[pluton]

I'm not Richard, but I can offer 2 from my own personal observation: 85/1.4 AiS and 135/2 AiS:  Scotch tape for locking the infinity focus adjust.  Makes infinity adjustment very easy to do at home with camera zoomed-in on live view.  Not a downside IMO.  The tape is easily replaceable if it should disintegrate.

[Per Inge Oestmoen]

I'm not Richard, but I can offer 2 from my own personal observation: 85/1.4 AiS and 135/2 AiS:  Scotch tape for locking the infinity focus adjust.  Makes infinity adjustment very easy to do at home with camera zoomed-in on live view.  Not a downside IMO.  The tape is easily replaceable if it should disintegrate.

It would be good if it can be elucidated whether the Ai-S versions are really mechanically inferior to the AI versions.

Just one comment on plastic.

The use of plastic is in itself not indicative of lower quality. It depends on what kind of plastic it is, and where it is used. Chap, recycled plastics which are not resistant to UV/oxygen and ageing is always bad if you want something to last. However, UV- and oxidation resistant plastics of premium quality does not reduce quality.

[Jack Dahlgren]

Simpler can be better. Plastic can be better. Tape can be better than glue. Rubber can be better than metal. But the converse can be true as well. The old lenses (AI and AIS) I’ve worked on are easier to actually repair as the entire thing can usually be disassembled, rebuilt and readjusted. Perhaps this does not make them more robust, but certainly makes them more satisfying to work on.

[Roland Vink]

The early AI-S lenses are mostly (all?) metal, I think the beauty ring of the AI-S 50/1.4 and AI-S 50/1.8 (long nose) are plastic but that's about as far as it goes. The series-E lenses from the same period did use plastic. By the mid 1980s the series-E line was discontinued, or rather, merged with the Ai-S line, and you start to see series-E features appearing in Ai-S lenses. The most obvious is the newer pancake 50/1.8 which has a mostly plastic exterior, and is really a remodeled series-E lens. Zooms from that period also have plastic parts, the Ai-S 35-70/3.3-4.5 has a mostly plastic exterior and the aperture ring of the 28-85/3.5-4.5 is also plastic.

AI-S lenses introduced in that period also tend to have a black anodized finish on the metal parts, like Series-E lenses, rather than the black enamel finish of earlier AI-S lenses. For example, the AI-S 100-300/5.6 at first glace seems like a longer version of the 80-200/4, but the design and finish is really closer to the Series-E 70-210/4.

Overall I would say there was a small decline in build quality which already started during AI production. Very early AI lenses were engraved LENS MADE IN JAPAN which was filled in white paint. This soon changed to unpainted MADE IN JAPAN. This is not really a reduction in build quality but it's less "luxurious" and shows Nikon was trying to reduce costs and simplify production. Early AI lenses also have 5 screws in the mount, but this dropped to 3 screws for most primes 85mm and shorter. Having 5 screw probably wasn't really needped for small lenses so this was a sensible simplification in production. With the transition to Ai-S most lenses up to 135mm have only 3 screws in the mount.

I can only guess there were similar internal changes to streamline the assembly process and reduce costs. I don't know much about the internal workings, but I know that early production of the Japanese AI-S 50/1.8 pancake lens used brass focus helix, but this later changed to aluminium, so it's possible the same occurred with some other AI-S models as well.

[pluton]

I can only guess there were similar internal changes to streamline the assembly process and reduce costs. I don't know much about the internal workings, but I know that early production of the Japanese AI-S 50/1.8 pancake lens used brass focus helix, but this later changed to aluminium, so it's possible the same occurred with some other AI-S models as well.

What other early N/K/Ai/AiS era lenses had dissimilar metal helicoids?  My impression is that very, very few of them did.
To be fair to Nikon, all of Nikon's direct competitors in the SLR market seemed to mostly use all-aluminium helicoids, so that was the market Nikon had to compete in.

[ggoodes]

This is a curious lens in some ways. It comes after the AI and AIS 105/4 micro which has a remarkably simple optical design with just 5 elements in 3 groups and no floating elements (or AF, VR ...), It focuses purely by extension giving a very long working distance for this class of lens. Optical performance is pretty even at all distances, perhaps a little weaker at infinity, and contrast is excellent due to the simple optics. It also has a useful built-in hood (especially the AIS).

The AIS 105/2.8 by contrast has much more sophisticated optical design. It has 10 elements in 9 groups - twice the number of elements and three times the air-glass surfaces. It has three "groups" of elements - a fixed teleconverter group at the rear, and two at the front in a double-gauss configuration with CRC. All this achieves a one stop advantage in speed. Sharpness is excellent, better than the old lens at distance, and about the same up close. But the working distance is shorter due to focal length shortening at close range. Operation with extension tubes is somewhat compromised due to the CRC mechanism. Contrast is lower due to the higher number of elements (my sample has newer SIC coating, looking into the front it does not look very transparent, even compared to other lenses with similar number of elements, not sure why). And for all the optical wizardry it still only gets to 1:2. There is no longer a built in hood either.

The AF 105/2.8 micro has a similar but refined optical design with 9 elements in 8 groups. It can go directly to 1:1 without extension tubes and contrast seems to be a little better - the front lenses do look more transparent. However it is relatively bulky and has more extreme focal length shortening at close range, and the focus throw is short - focusing near infinity requires a very fine touch.

Between the AIS 105/4 and AF 105/2.8 micro (and 105/2.5) I bypassed the AIS 105/2.8 micro for many years. Last year I decided to buy one and have not been disappointed. Of the 105 micros it is the most compact and the f/2.8 makes it useful as a general purpose tele which focuses closer than my 105/2.5. Sharpness is excellent and the bokeh is smooth - better than the AF which is a little harsh. The lower contrast hasn't been a problem either. Maybe it is not as robust as some other lenses, but I'm not hard on my gear so it should last for years.

A full set of extension tubes from the PK-11a, PK-12, PK-13 and PN-11 can allow keeping the 105/2.8 AIS Micro with the focus ring close to the near focus limit. One will use the shortest tube necessary. This should keep the CRC in a better position for flat field subjects.

Couldn't resist commenting on this (very old) thread.  I "upgraded" my 105/2.5 AiS to a Micro 105/2.8 + PN-11, hoping to get the benefit of close-focus/macro without sacrificing the ability to shoot portraits/landscapes that the 105/2.5 afforded me.  After several years, I realized I had made a mistake: I never really felt the 105/2.8 gave me the same painterly results for portraiture, and while the macro results down to 1:2 were quite good, using the PN-11 to go closer often gave poor results.  I later figured out that the problems was the CRC giving a kind of dead-zone with the PN-11 until you approached 1:1.  In those days I didn't own the smaller extension rings (though I have a complete set now), and even had I wanted them would have had to pay too much (due to living in Copenhagen == $$$ for even used camera gear).

I have subsequently re-purchased a 105/2.5 AiS and hardly ever take my Micro 105/2.8 out of it's case.  For macro work, I have the Voigtländer 125/2.5 APO-Lanthar and just got an AM-ED Nikkor 120/5.6 for use on my PB-4, either of which gives _amazing_ results with none of the concerns of the Micro 105/2.8 + PN-11.

On the original question of AI versus AiS: I'm firmly in the AiS camp.  As an amateur street-photographer, the shorter focus-throw is preferred, and I actually _like_ the 105/2.5's built-in hood (wobbliness aside!).  I also made use of an FA on occasion, so the "S" design updates were needed.  I was never much of a Bokeh guy, so the curved vs. straight aperture blades were not important to me.  And I was around in the era of the Series-E "plastic fantastic" introduction, so the build-quality of AiS seemed great to me (honestly, 3 vs 5 screws on the bayonet doesn't seem like "cheaping out" on a 24/2).