AI superior to AI-S?

[John Koerner]

I own both versions of the Noct-Nikkor and really don't bother which one is attached to my camera. Used wide or near wide open, they are essentially the same.

I want to re-visit this statement.

Okay, optically, let's say they're indistinguishable ... so the real question is, Which do you prefer using--and why?

Which focusing experience do you prefer, the AI with the longer throw, or the AI-S?

[John Koerner]

I have one of the 55/1.2 K(Ai'd) and, though I have never shot the 58mm Noct, I can tell you that the 55/1.2 has pronounced spherical aberrations wide open that make the images even dreamier than the famous look of the old manual focus 35/1.4 wide open.  It really qualifies as a 'special effect' IMO.

Thanks for that info. Very descriptive and helpful.

I can't imagine the famous 58mm Noct looks that soft wide open.

I guess it's all relative.

For its time, the Noct was "razor sharp" wide-open ... but compared to the 105 f/1.4 the Noct is as dull as a butter knife.

The Noct isn't even in the same balpark, sharpness-wise, at any aperture, as the 105 f/1.4.

Curiously, once stopped down to f/4 or more, the 55/1.2 K is a very contrasty, "sharp" lens.

The 55 f/1.2 K sounds exactly like the 50 f/1.2 AI-S, which too is about half as sharp as the so-so Noct wide-open ... but rockets to equal the Noct's sharpness by f/4.





The amazing thing is, neither one of these lenses, at their best, can equal the sharpness of the 105mm f/1.4 at its worst

 

Jack

[John Koerner]

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 

Thank you for this insight.

Other than the glue part, I remain increasingly-biased toward the AI lenses over the AI-S versions (with some exceptions, of course).

Cheers,

[Bjørn Rørslett]

I want to re-visit this statement.

Okay, optically, let's say they're indistinguishable ... so the real question is, Which do you prefer using--and why?

Which focusing experience do you prefer, the AI with the longer throw, or the AI-S?

As my mind never walks these directions, there is no answer other than the obvious: the one mounted on my camera.

[Erik Lund]

John the 105mm AFS 1.4 is another kind of tool and comparing sharpness numbers is not really leading anywhere in describing the differences or the likeness IMHO

As mentioned; You will find that the Noct-Nikkor is capable of creating an images that has the similar qualities as an APO Lanthar 125mm - That should tell something!

Noct-Nikkor on D3 wide open:

_EGL4003 by Erik Gunst Lund, on Flickr

100% crop

100 by Erik Gunst Lund, on Flickr

Have a look at the single hair strands strands and the colour transitions,,,

[John Koerner]

John the 105mm AFS 1.4 is another kind of tool and comparing sharpness numbers is not really leading anywhere in describing the differences or the likeness IMHO

Eric, I was comparing sharpness because Pluton compared the sharpness of the 55 f/1.2 to the 58 f/1.2 Noct.

As mentioned; You will find that the Noct-Nikkor is capable of creating an images that has the similar qualities as an APO Lanthar 125mm - That should tell something!

Actually, what it tells me is the Noct is virtually last on my list as a needed item, especially considering the price.

I already have the color-rendering of the APO Lanthar, and my own preference (style-wise) is super sharp images with a nice bokeh background.

If I need super-sharp, wide-open shots, with nice bokeh background, the 105 f/1.4 would suit my preferences better. The added bonus of this kind of quality, with auto-focus, and being half the price of a Noct (whilst twice as sharp wide-open) makes the 105 ED even more likable.

Because I don't shoot a lot of night photography, the only area where the Noct excels, makes this lens something I would seldom benefit from by comparison to the aforementioned.

Noct-Nikkor on D3 wide open:

100% crop

Have a look at the single hair strands strands and the colour transitions,,,

Cool

[chambeshi]

This is a most interesting thread, summarizing many nuggets of wisdom.

With reference to the criteria of sharpness of 1) focal subject 2) bokeh and rendering of background, 3) colour saturation and the often lauded quality of 3-dimensionality....

I am most interested in opinions of how do the 58 f1.4 Voigtlander and 135 f2 Zeiss APO Sonnar compare against the top Nikkors and other top lenses ?

thanks

Woody

[Roland Vink]

I'm coming into this discussion late as I have been away. Some comments:

Construction
If weight can be used to determine build quality, most AI and AIS equivalents are the same. In some cases the AIS is slightly lighter but some are slightly heavier. I don't know the quality of internal construction - our lens doctors Eric and Ric have commented on that. Most smaller AIS lenses have only 3 screws in the mount but that is perfectly sufficient, early AI lenses have 5 screws but this already reduced to 3 screws during production.

Focus Throw
Most AI lenses have a longer focus throw than AIS equivalents. If you prefer lenses with a longer focus throw for slow precise focusing, the AI version is generally preferred. Once you get to about 180mm and beyond there is no difference (the AIS 135mm Nikkor still have a shorter focus throw, not the same as the OP claimed).

In one case, the AI 35/2.8 (new) the focus throw is shorter than the AIS version, although the older AI 35/2.8 (6 element) is even longer.

In some cases I find the focus throw of the AI version is too long, such  as the AI 55/1.2 and 85/2 - these lenses are very slow to focus, I prefer the AIS versions.

To correct an earlier assertion, the focus throw of the AIS 28/2.8 is actually shorter than the older AI versions, even more so when you consider the AIS version has a greater focus range within that focus throw. In the range between infinity and 0.3m, the AI 28/2.8 has over twice the focus throw at 190° compared to just 90° for the AIS.

The focus throw is listed on my lens specification page: http://photosynthesis.co.nz/nikon/specs.html

Optics
Most AI and AIS lenses have the same optical designs (to the best of my knowledge). Lenses which changed include:

- AI 18/4 -> AIS 18/3.5. The new lens benefits from CRC a more compact design.

- AI 28/2.8 -> AIS 28. The new lens get CRC and focuses much closer. In spite of this difference the optics are surprisingly similar, the thick central element of the AI is split in two with CRC applied across the gap (of course there is more to it than that). Both lenses have very low barrel distortion, but the AIS obviously performs better at close range.

- AI 55/3.5 -> AIS 55/2.8 micro. Again, the new version gains CRC and a small increase in speed.

- AI 180/2.8 - AIS 180/2.8 ED. The AIS version has an all-new optical design with ED glass.

You could also include the AIS 20/2.8 and 105/2.8 micro which both gained CRC and an increase in speed over the earlier versions, but these lenses appeared later on, there are also older AIS versions with the same optics as the AI type.

The NIC coatings on AI and AIS lenses are generally similar, although AIS lenses made after about 2000 have the newer SIC coating. I'm not sure whether the new coating makes a big difference, the original NIC coating was already very efficient.

Other

- The AIS 105/2.5 has a built in hood (small and wobbly) while the AI does not - use the larger clip-on HS-8 which can be reversed for storage

- The built-in hood of the AI 135/3.5 is longer than the AIS hood. I prefer the AI for the better hood and longer focus throw.

- AI 28/2, 58 Noct and 105/2.5 have slightly curved aperture blades for rounder bokeh, while the AIS versions have straight blades.

- The AIS 35/1.4 and 50/1.2, 58 Noct and 300/4.5 IFED have 9 aperture blades while the AI have only 7. The non-ED 300/4.5 goes from 6 to 7 blades.

- the AI and AIS 200/4 have 9 aperture blades but the AI blades are a little short, the tips don't overlap fully giving a saw-tooth opening. The AIS is better. There may be others like this.

- AIS 200/4 micro, 300/4.5 IFED and 400/5.6 IFED have wider tripod collars than AI, these are very solid! The AI collars are not bad however. On the other hand the AI versions have wider aperture rings.

- the AIS 28/2 focuses closer than the AI version although the optics are basically the same.

There are other minor differences that I have overlooked. Overall you can't make blanket statements about AI vs AIS, you need to consider the merits of each lens and your own preferences. Most specifications, including focus throw, number of aperture blades etc are listed here: http://photosynthesis.co.nz/nikon/lenses.html

[John Koerner]

To correct an earlier assertion, the focus throw of the AIS 28/2.8 is actually shorter than the older AI versions, even more so when you consider the AIS version has a greater focus range within that focus throw. In the range between infinity and 0.3m, the AI 28/2.8 has over twice the focus throw at 190° compared to just 90° for the AIS.

Roland;

Really appreciate your feedback ... and appreciate your website all the more. Great, great stuff

That said, I think you're mistaken on the 28mm AIS. Your own reference site lists 190° for the AI and 170° for the AIS, which is negligible.

I just tested my own AIS copy, and indeed it is right around 180° in turning the focus dial. That, coupled with the better CRC, is why I keep the 28mm AIS over the alternative.

Much obliged for your other insights, thanks!

Jack

PS: Which Noct do you prefer, personally?

[Roland Vink]

John, no mistake, the focus throw of the AIS 28/2.8 is shorter (170°) than the AI (190°), not a big difference as you say. However the AIS requires just 90° rotation to get to 0.3m (the close limit of the AI) so when focusing to the same distance, the AIS has about half the focus throw of the AI. The AIS focus throw only seems longer because it also focuses closer.

Similar situation with the AI and AIS 28/2 - both have a focus throw of 120°, but the AI only focuses to 0.3m, while the AIS focuses to 0.25m - the AIS has a greater focus range within the same rotation, so when focusing to the same distance the AIS will actually require a shorter movement.

Also compare the focus throw of the AIS 35/2 (120°) with the AIS 35/1.4 (105°). On paper it looks like the 35/1.4 has a shorter focus throw. They are actually the same because the 35/1.4 has a fatter barrel - the larger diameter means the same movement of the focus ring covers a shorter angle.

For this reason I sometimes wonder if the focus throw as an angle is the best measure, maybe a linear measure would be better (eg AIS 35/1.4 requires XXmm movement of the focus ring between infinity and 0.3m)??


Which Noct I prefer? The cheapest! I would love to have one but can't justify the cost.

The AI has 7 aparture blades which are slightly curved so the opening has a nice rounded look.
The AIS has 9 blades - more blades so it is rounder but they have straight edges - which is better?

The AI has a focus throw of about 230° which is similar to my AI 55/1.2 - very slow to focus from infinity to close, but fine if you tend to focus within a limited range.
The AIS has a focus throw of 140°, I think I would prefer this for general use. This is the same as the AIS 50/1.4 - but note the 50/1.4 has a slimmer barrel so it's focus throw is proportionally shorter - if you have one it will give you an idea if the focus throw is right for you.

The AI Noct is rarer, fewer than 2500 made, compared to nearly 9000 for the AIS, so the AI will be harder to find.

[John Koerner]

John, no mistake, the focus throw of the AIS 28/2.8 is shorter (170°) than the AI (190°), not a big difference as you say. However the AIS requires just 90° rotation to get to 0.3m (the close limit of the AI) so when focusing to the same distance, the AIS has about half the focus throw of the AI. The AIS focus throw only seems longer because it also focuses closer.

Interesting perspective, Roland, thank you.

The overall focus throw is nearly identical (170° vs. 190°).

As you point out, the focus throw from .3 to ∞ is 190° in the AI and only 80° in the AIS.

Of course, that perspective could be flipped

The AI has 0° focus throw from .2 to .3, whereas the AIS has a whopping 90° degree of control over a mere .1m range

Similar situation with the AI and AIS 28/2 - both have a focus throw of 120°, but the AI only focuses to 0.3m, while the AIS focuses to 0.25m - the AIS has a greater focus range within the same rotation, so when focusing to the same distance the AIS will actually require a shorter movement.

Fascinating amendment to the overall focus throw quotient, thank you for turning the light one.

In the case of the 28mm, the extra 90° control over close-shooting suits me as a macro shooter, and is ideal for (say) coming up close to a flower, or mushroom, etc. and really nailing the focus ... while composing the background for effect. To me, combined with the CRC, this is preferable to "no" CRC ...

What is interesting is, I have read many websites and information on CRC ... and it was actually introduced in 1967 ... but not labeled on all lenses.

If I am not mistaken, the 28mm AI also has CRC ... just not to the degree of the AIS.

Also compare the focus throw of the AIS 35/2 (120°) with the AIS 35/1.4 (105°). On paper it looks like the 35/1.4 has a shorter focus throw. They are actually the same because the 35/1.4 has a fatter barrel - the larger diameter means the same movement of the focus ring covers a shorter angle.

Very interesting, thank you.

For this reason I sometimes wonder if the focus throw as an angle is the best measure, maybe a linear measure would be better (eg AIS 35/1.4 requires XXmm movement of the focus ring between infinity and 0.3m)??

I suppose there is no "one" answer.

In my 300 f/2.8 VR II, I don't care, because I use it 99.9999% of the time as an AF lens. I just want it to be quick when I half-depress the shutter.

OTOH, with my Voigtlander 125mm macro, I truly enjoy the 600°+ or focus throw for fine-tuning shots where ultimate sharpness and focus are mandatory.

The 28mm with CRC is more of a "perspective" lens than an ultimate sharpness lens. By that I mean, a close-up of a flower ... while positioning the background to be pleasing.

Which Noct I prefer? The cheapest! I would love to have one but can't justify the cost.

The AI has 7 aparture blades which are slightly curved so the opening has a nice rounded look.
The AIS has 9 blades - more blades so it is rounder but they have straight edges - which is better?

The AI has a focus throw of about 230° which is similar to my AI 55/1.2 - very slow to focus from infinity to close, but fine if you tend to focus within a limited range.
The AIS has a focus throw of 140°, I think I would prefer this for general use. This is the same as the AIS 50/1.4 - but note the 50/1.4 has a slimmer barrel so it's focus throw is proportionally shorter - if you have one it will give you an idea if the focus throw is right for you.

The AI Noct is rarer, fewer than 2500 made, compared to nearly 9000 for the AIS, so the AI will be harder to find.

I can't justify the cost either, but I will probably pick one up "just to say I have one" ... will go for the AI, both for rarity-sake, as well as better build quality and focus throw.

At that focal range, and with the characteristics of the lens (soft corners, center-sharpness, very fast), your background is going to be a blur anyway ... and you're really trying to augment the center-focus + dreamy background. Here, with a razor-thin DOF, the most precise focusing you can get your hands on is going to be preferable. At least to me.

Thanks again for the knowledgeable feedback ... much appreciated.

Jack

[Bjørn Rørslett]

There is no information concerning CRC and the 28/2.8 AI. So no reason to assume that lens version had the feature.

Two lenses in the 28 mm range do have CRC, viz. the 28/2 AI+AIS and 28/2.8 AIS. (plus the elusive 28/1.4 AF, but it is not relevant in the current context as there is no AI counterpart). Interestingly though these lenses did CRC by the front rather than the usual implementation with rear element(s).

[Erik Lund]

And that is also why these front CRC lenses are susceptible to getting out of alignment if the front of the lens or lens hood gets a knock rom the side.

[Roland Vink]

The AI has 0° focus throw from .2 to .3, whereas the AIS has a whopping 90° degree of control over a mere .1m range

If the AI also focused to 0.2m and the focus pitch was kept the same, it would require near 180° to cover the distance between 0.3 ~ 0.2m...

If I am not mistaken, the 28mm AI also has CRC ... just not to the degree of the AIS.

I assume you are referring to the 28/2? If so, yes, it does have CRC, but the AIS the extends the focus range further, not sure if they made any other refinements to the optical design.

If you were referring to the 28/2.8, the AI and pre-AI versions don't have it, only the AIS.

As for how CRC is implemented, as Bjørn said, the AIS 28/2.8 and 28/2 versions have the floating group at the front - when focusing you will see that the front element rotates inside the mount, and the gap between the front element and filter ring increases slightly. Other lenses with CRC implemented at the front include the AIS and AF 20/2.8, AF 16/2.8 fisheye, and possibly the AIS 18/3.5.

[David H. Hartman]

Okay, optically, let's say they're indistinguishable ... so the real question is, Which do you prefer using--and why?

Which focusing experience do you prefer, the AI with the longer throw, or the AI-S?

For me this is mixed: the AIS Nikkors are generally smoother focusing with a shorter throw on the focus ring. This is good for PJ, PR, candid and street photography. I used to have a strong preference for AIS. AI Nikkors even new out of the box never seemed as smooth as AIS Nikkors. The long throw of AI Nikkors is a benefit to accurate focus and focus with live view.

Diffraction stars: an odd number of straight blades give a star with twice the spokes as the number of blades. I like 9 blade straight apertures more prevalent on AIS Nikkors for their 18 spoke stars. 7 blade straight aperatures give 14 spoke stars which is fine. 6 blade straight blade apertures give 12 spokes but they are superimposed on each other and you see only six spoke stars.

I also prefer odd sided polygon bright out of focus highlights and more sides are generally better.

So AIS v. AI is mixed for me.

Dave Hartman