Interview to the designers of AF-S 105/1.4E

[Akira]

John, Erik, chambeshi, Dave, I'm glad you enjoyed the article and my humble summary.

In the larger part of the second part, the interviewer asked nerdy questions about the aberration correction.  If you are interested, I will be glad to summarize it.

[Akira]

As for the proposed 100/1.4 lens, it would have an entrance pupil = 71mm which is 6mm smaller than 77mm filter.
This is identical to the Canon 85/1.2, a faster lens with wider angle of view, so 100/1.4 with 77mm filter should be less difficult. Of course it is likely the 85/1.2 has very high mechanical vignetting.

Nikon have made a number lenses with similar focal length which have very tight margin between entrance pupil and filter:
Lens        Pupil  Filter
Auto 85/1.8  47     52
Noct 58/1.2  48     52
AIS 105/1.8  58     62
AIS 135/2.8  48     52

I would suspect that the vignetting was not considered as critically up to the Ais era as in later years.  For example, the AF and AF-D 85/1.8 already had 62mm filter threads.  As you know, the designers of 58/1.4G said that they decided on f1.4 instead of f1.2 to avoid the excessive vignetting.

[Erik Lund]

I really like vignetting in fast lenses to keep the image together, is very nice and often supportive in slim dof images.
Also with todays amazing image quality from the cameras/sensors vignetting is so easy to fix/manipulate in PP.

After shooting a lot with the 105mm 1.4 AFS E and seeing others images from the same lens I notice more and more the swirly Bokeh when there are highlights in the background.

These are more noticeable than for instance compared to the Bokeh ball from Nikkor 135mm AF-D 2 DC or 125mm 2.5 APO Lanthar - the 105 1.4 Bokeh Balls have more of an sharp corner in the two corners where they are cut off,,,

[Akira]

Experience photographers would know how to live with or make use of the vignetting.  As mentioned in another thread, the Yahica/Contax Distagon 25/2.8 showed excessive vignetting even well stopped down and was known as "favorite lens for connoisseurs" (at least in Japan) who liked to use it as the positive image effect.

Admitting that the vignetting is rather a favored effect for some, it would be an issue to address for the lens designers.  Sigma also mentions (or even boasts about) the rich amount of light in the peripheral image area achieved by their Art 50/1.4.

[Roland Vink]

--105/1.4E was intended as the lens that celebrates the 100th anniversary (in 2017) of the foundation of Nikon company, and originally designed as a 100mm lens.  For the coherency in the existing product line, however, it was redesigned as a 105mm one.

Interestingly, Lensrentals measured the focal length to be 101mm, maybe it was designed as 100mm after all?

"... the numbers suggest since the Nikon actually is 101mm at infinity, not 105mm"
See: https://www.lensrentals.com/blog/2016/11/nikon-105mm-f1-4-e-mtf-bench-tests/

Maybe someone who has this lens can compare with other 105mm lenses to see if the field of view is wider or the same...

[Akira]

LOL!  You would have to compare it with, say, the venerable 105/2.5!

I have once tested two different AF-S 35/1.8 lenses (DX and ED) on my D7000 side by side at the Nikon Showroom.  Focused at a fairly far subject (at least tens of meters), the ED (FX lens) showed noticeably wider angle of view.  So, I wouldn't be surprised by the deviation of the actual focal lengrh from the nominal one.  It is still within the 5% tolerance.

[Frank Fremerey]

Very interesting. Thank you for your translation.

[Akira]

You are welcome, Frank.

[Roland Vink]

LOL!  You would have to compare it with, say, the venerable 105/2.5!

At least we can be sure that lens really is 105mm:

[Ilkka Nissilä]

Maybe it should have stated "redesignated" instead of "redesigned".

[Erik Lund]

At least we can be sure that lens really is 105mm:

Roger C tested the new 105mm AFS 1.4 to be 101mm at infinity

[Akira]

Roger C tested the new 105mm AFS 1.4 to be 101mm at infinity

Yes, we know.  I was curious about the actual focal lengths of other Nikkor 105s.  Ais Micro 105/2.8 is known to be 82mm with the built-in teleconverter.  How about Ai/Ais Micro 105/4.0?

[Erik Lund]

Yes, we know.  I was curious about the actual focal lengths of other Nikkor 105s.  Ais Micro 105/2.8 is known to be 82mm with the built-in teleconverter.  How about Ai/Ais Micro 105/4.0?

Not obvious form the thread,,,

Anyway the old 105mm 4 Ai Ais is unit focusing so must be very close to 105mm

[atpaula]

Thank you so much for the article and translation Akira. Really generous of you.

[Akira]

Not obvious form the thread,,,

Anyway the old 105mm 4 Ai Ais is unit focusing so must be very close to 105mm

Sorry to be unclear.  I've forgot that a Micro lens should offer correct magnification along with the 52.5mm extension tube, so it should be 105m!

Aguinaldo, glad to be of any help.