micro-nikkor 105mm f/4 Ai-S!!!

[richardHaw]

Spherical aberration is fine with me, along with some chromatic aberration but this is a macro lens so i'd rather not see it

i checked my tests of the 105/2.8ais and indeed the f/4 is sharper

[Roland Vink]

At what distance? The 105/4 is a unit focusing lens - no floating elements - so it can be optimised for only one distance. For example the AI 55/3.5 micro is optimised at 1:10, I'm not sure if the 105/4 is the same. At distances outside the optimum range I expect field curvature and spherical aberrations to become progressively worse. With a well designed lens, the drop in performance can be kept minimal so it can be used successfully at all distances.

The AIS 105/2.8 micro does have floating elements, the basic structure is a double-gauss 75mm f/2 lens with close range correction applied between the front and rear groups, and a 1.4x teleconverter fixed at the rear, so there are three groups of lenses which should prove a higher level of correction at all distances. Surely the Nikon designers would have wanted their new f/2.8 macro to be superior to the older model over the entire focus range.

The increase of one stop and CRC means the new lens has twice as many elements, the extra glass/air surfaces means is has lower contrast when shooting into strong light (the 105/4 isn't perfect either in spite of only 5 elements in 3 groups). Also, the AIS 105/2.8 micro has a shorter focus distance at close range and doesn't work so well on extension, so you could question whether the newer lens is an all-round improvement, but I would be surprised if it isn't sharper between infinity and 1:2.

I have heard the CRC mechanism of the AIS 105/2.8 is delicate, a knock to the front could put it out of alignment. Maybe that, or the lower contract could account for the lower perceived sharpness?

[richardHaw]

I have heard the CRC mechanism of the AIS 105/2.8 is delicate, a knock to the front could put it out of alignment. Maybe that, or the lower contract could account for the lower perceived sharpness?

at 1:1 or anywhere near it. CRC to my knowledge is mostly apparent at the corners.
it is possible that the 105/2.8 is better at a distance and the 105/4 at closer to 1:1 since the latter was originally designed as a bellows-only lens?

it appears that the 105/4 is sharper by about 2/3 of a stop, i think the 105/4 looks better at f/4 than the 105/2.8 at f/4 (center), its true that the CRC may be misaligned so i am getting these results.

if i am not mistaken, the 105/2.8D is the sharpest Nikkor 105 i have tried, even sharper than the 105VR at f/16. i will never use the 105VR at f/16 but the older 105/2.8D is not so bad at that aperture. that was a huge disappointment because i used to take a lot of bug photos and dof is very important to me.

[richardHaw]

in case anybody is curious, the https://richardhaw.com/2020/05/02/repair-micro-nikkor-5cm-f-3-5-ltm/ oldest micro-nikkor performs MUCH better compared to all of the 105 that i have ever tried

[David H. Hartman]

Any explanation for the use of the word "Micro" v. "Macro?" The Nikon Nikkormat Handbook by Joseph D. Cooper gave an explanation but I don't remember what it was.

Dave

[Akira]

Any explanation for the use of the word "Micro" v. "Macro?" The Nikon Nikkormat Handbook by Joseph D. Cooper gave an explanation but I don't remember what it was.

Dave

What I have understood (at least in Nikon terms) is that Micro is for the lenses that go up to 1:1, and Macro for the ones that go from 1:1 and larger.

[Erik Lund]

Some zoom lenses have a Marco setting to give some better close up performance.

All of the special purpose F-mount lenses capable of infinity to 1:1/1:2 are called Micro-nikkor

The Nikon Multiphot lenses are called Macro-Nikkor and Macro Nikkor

Then there are Ultra-Micro-Nikkor, Nikkor-AM and others

[Roland Vink]

at 1:1 or anywhere near it. CRC to my knowledge is mostly apparent at the corners.
it is possible that the 105/2.8 is better at a distance and the 105/4 at closer to 1:1 since the latter was originally designed as a bellows-only lens?

If the 105/2.8 is attached to a PN-11 and focused all the way out, the CRC should be arranged fully for close up shooting, although it will be optimised for 1:2 not 1:1, so it is probably not strongest at this magnification. (The worst case is attached to the PN-11 and "focused" to infinity for 1:2 magnification. In this setup the optics are optimised for infinity, not 1:2 so you should expect performance to be poor. Much better to remove the extension tube and focus all the way out. To repeat what David said: "The lens should be kept at its minimum focus position and as little extension used to achieve the desired image ratio.")

Similarly, if 105/4 was optimised for 1:10 magnification, it probably is not perfect at 1:1. It is likely the AF 105/2.8 micro is better at 1:1 since it can achieve this magnification without extension tubes.

[David H. Hartman]

I'm experimenting with my 105/4.0 AI Micro-Nikkor at two to three meters using the matte surface of the focus screen and electronic focus assist in my D850. I using a Nikon DK-17M (1.2x) eyepiece and the 30x20mm format as I can see the complete image area with that image area setting while wearing my glasses. That combination offers a finder magnification of 0.96x (50mm at infinity) which is just at the edge that I can manage.

I'm thinking the D500 with a 1.0x viewfinder and 1.2x, DK-17M eyepiece (1.2x combined) would work very well for me. The approximate angle of view of the 105/4.0 Micro on the 24x16mm format is roughly the same as a 160mm lens on FX. Maybe some day I'll own a D500. 

Dave

[richardHaw]

for variety and to confuse you guys even more, I will add the 5cm/3.5 into the mix
i will shoot a few samples with it using some extension tubes that I salvaged from a Chaika

[Erik Lund]

for variety and to confuse you guys even more, I will add the 5cm/3.5 into the mix
i will shoot a few samples with it using some extension tubes that I salvaged from a Chaika

We have other threads on the 55mm Micro Nikkors you know 

[Gerhard2006]

The AIS 105/2.8 micro does have floating elements, the basic structure is a double-gauss 75mm f/2 lens with close range correction applied between the front and rear groups, and a 1.4x teleconverter fixed at the rear, so there are three groups of lenses which should prove a higher level of correction at all distances. Surely the Nikon designers would have wanted their new f/2.8 macro to be superior to the older model over the entire focus range.   

This is interesting Roland where did you get this information from? I always thought the last four elements look like a tele-converter. So as the front elements move forward, they magnify the image and the focal length increases instead of decreasing as most CRC systems do. Regards Gerry

[Roland Vink]

This is interesting Roland where did you get this information from? I always thought the last four elements look like a tele-converter. So as the front elements move forward, they magnify the image and the focal length increases instead of decreasing as most CRC systems do. Regards Gerry

Some information is in the article about the AF 105/2.8 micro: https://imaging.nikon.com/history/story/0072/index.htm which was a development of the AI-S 105/2.8 micro:
Reducing the amount of movement required by adding a teleconverter behind the Gauss structure followed the AI Micro-Nikkor 105mm f/2.8S upon which this lens was based.

More information about the AF 105/2.8 micro here: http://www.pierretoscani.com/focale.html#focale37Animation
- a mobile primary lens of the “double Gauss” type (focal length: 75 mm) equipped with a correction system for close focusing
- an integrated and fixed rear converter with a coefficient of 1.4x (see following figure).

The AI-S has an optical system with a double-gauss structure at the front. Like the AI-S 55/2.8 micro, close range correction is applied by opening up the space between the front and rear groups. This has the effect of increasing the focal length at close range. On the other hand, the rear teleconverter has the effect of reducing the focal length at close range, which more than cancels out the increase in the front group, and reduces the overall amount of extension required to achieve 1:2 magnification.

[richardHaw]

oh, putain...the link is very informative but the important bits in the animation are in French

[Gerhard2006]

Well thanks for sharing this website Roland and this information on the 105 2.8 Ais It really is an incredible engineering feat. Regards Gerry

Some information is in the article about the AF 105/2.8 micro: https://imaging.nikon.com/history/story/0072/index.htm which was a development of the AI-S 105/2.8 micro:
Reducing the amount of movement required by adding a teleconverter behind the Gauss structure followed the AI Micro-Nikkor 105mm f/2.8S upon which this lens was based.

More information about the AF 105/2.8 micro here: http://www.pierretoscani.com/focale.html#focale37Animation
- a mobile primary lens of the “double Gauss” type (focal length: 75 mm) equipped with a correction system for close focusing
- an integrated and fixed rear converter with a coefficient of 1.4x (see following figure).

The AI-S has an optical system with a double-gauss structure at the front. Like the AI-S 55/2.8 micro, close range correction is applied by opening up the space between the front and rear groups. This has the effect of increasing the focal length at close range. On the other hand, the rear teleconverter has the effect of reducing the focal length at close range, which more than cancels out the increase in the front group, and reduces the overall amount of extension required to achieve 1:2 magnification.