NIKON

Optical Design value Analysis - NIKON NIKKOR 14-24mm F2.8 F vs Z -wide part[No.034]

2022-11-19

This article compares the wide-angle (14 mm) performance of Nikon's large-aperture F2.8 super-wide-angle zoom lens, the F mount Nikkor 14-24 F2.8, and the Z mount Nikkor Z 14-24 F2.8.

You hardly understand the specific differences in how the lenses work and how their performance differs from each other, do you?

Even if you look it up in magazines or on the Internet, all you will find are similar "word-of-mouth recommendations" and articles like that.

In this blog, while researching the history of lenses and their historical background, we estimate lens design performance based on patent information and actual shooting examples, and analyze lens performance in detail from a technical viewpoint through simulations.

Professional lens designer Jin Takayama will carefully unravel optical characteristics such as optical path diagrams and aberrations, which are generally not visible, and explain the taste and descriptive performance of lenses in a deep and gentle manner.

Now, please enjoy the special information that you can read only on this blog in the world.

For specific analysis articles, please refer to the following links:

Overview

The F14-24F 2.8 is used for the F-mount NIKKOR 14-24, and the Z14-24F 2.8 is used for the Z-mount NIKKOR 14-24.

After launching the Z-mount system in 2018, NIKON introduced three large-aperture zoom units (F2.8) called "Dai-sangen Zoom" to the market approximately two years later.

In the Z-mount market, Canon's lineup of so-called professional-use lenses effectively marked the end of SLR cameras and the advent of mirrorless cameras.

In this article, we compare the wide-angle ends of these two lenses.

See each page for a detailed analysis of each lens.

Private Memoirs

The development of wide-angle zoom lenses is technically equivalent to the development of aspherical lenses.

Because for wide-angle lenses, if larger aspheric lenses can be manufactured and put into products, the performance will be better by that amount.

Manufacturers with more advanced manufacturing technology can change the design to a wider range of specifications, reduce the size, and improve the performance.

The previous F-mount lens went on sale in 2007, and the new Z-mount went on sale in 2020.

How much progress has been made in manufacturing aspheric surfaces over a period of about 13 years? We should be able to verify this by comparing and analyzing new and old products.

Also of note is that the Z-mount is a mirrorless mount.

A single-lens reflex camera needs to have a large space between the lens and the image sensor in order to secure the arrangement space of the mirror.

However, a wide-angle lens is also called a "lens with short focal length".

Since a lens has a short focal length, it is natural to have a short overall length. However, a lens for a single-lens reflex camera must have a large space for a mirror (i.e., a long lens). This kind of contradiction occurs.

Because of this contradiction, it has been difficult to improve the performance of wide-angle lenses for single-lens reflex cameras, and the effect of the mirror space must be great as far as ultra-wide-angle zoom is concerned.

Finally, mirrorless mounts should be free from this restriction and allow for free optical design, but by analyzing these 14-24 ultra-wide-angle lenses, we should be able to enjoy the benefits of free optical design.

Amazon Product Link
Click here to check prices

NIKON NIKKOR Z 14-24mm F2.8 S

Notes!

The following design values have been selected and reproduced from the appropriate patent literature and do not correspond to the actual product. Naturally, the data is not guaranteed, and I am not responsible for any accidents or damages that may occur by using this data.

Analysis of Design Values

Optical Path Diagram

The left side (blue) of the above figure shows the optical path of the old lens F 14-24 F2.8, and the right side (red) shows the optical path of the new lens Z 14-24 F2.8 at the wide-angle end.

The optical path diagram in the usual analysis article has the lens drawn to fill the frame, but this time it is drawn at the same scale ratio for comparison.

At a glance, you can see that the new NIKKOR Z 14-24 F2.8 lens is much smaller than the NIKKOR Z 14-24 F 2.8 lens.

Also, since the new lens Z 14-24 F2.8 is a mirrorless lens, we can see that it is closer to the image sensor than the old lens.

When you check the arrangement of the aspherical lens colored in red, the new lens Z 14-24 F2.8 has an aspherical lens on both sides as the first lens.

Since the aperture is huge and the shape is very distorted, it is probably very difficult to process.

The fact that such aspherical lenses were distributed in the market is thought to be the result of the high manufacturing technology that has been established in the last 10 years.

An aspheric lens placed as close as possible to the subject side of the lens is effective in correcting field curvature and distortion.

Both types of aberration are more difficult to correct than wide-angle lenses.

Then, let's look at the aberration diagram to see what kind of correction effect there was.

Longitudinal Aberration

The left lens (blue) is the old lens F 14-24 F2.8, and the right lens (red) is the new lens Z 14-24 F2.8.

Graphs of spherical aberration, image surface curvature, and distortion

Spherical Aberration , Axial Chromatic Aberration

The spherical aberration of the new lens Z14-24F 2.8 has been corrected to about half of that of the old lens.

Axial chromatic aberration is also corrected to the same level.

Image Surface Curvature

The curvature of field has also been reduced by half.

Distortion

Distortion is surprisingly at the same level. Did they give priority to miniaturization? In digital products, distortion is easily corrected by image processing, so they may have left it to image processing and sacrificed it.

This is my personal hobby, but with wide-angle lenses, I like to have a little bit of distortion left because if there is distortion left, it will make the photo look like a wide-angle lens.

Chromatic Aberration

The left lens (blue) is the old lens F 14-24 F2.8, and the right lens (red) is the new lens Z 14-24 F2.8.

According to the magnification chromatic aberration chart, the new lens Z14-24F 2.8 has been improved by approximately half.

Transverse Aberrations

The left lens (blue) is the old lens F 14-24 F2.8, and the right lens (red) is the new lens Z 14-24 F2.8.

(Left)Tangential direction, (Right)Sagittal direction

Let's look at it as transverse aberration.

As with the longitudinal aberration, the transverse aberration of the new lens Z14-24F 2.8 has been improved over the entire area.

Spot Diagram

The left lens (blue) is the old lens F 14-24 F2.8, and the right lens (red) is the new lens Z 14-24 F2.8.

Spot Scale 0.3 (Standard)

Now we are going to look at the optical simulation results, but at the spot diagram first.

In both cases, the spot size is too small to be distinguished by the standard scale.

I can't tell which side is the center side of the screen for a moment.

Spot Scale 0.1 (Detail)

This spot diagram has been enlarged by changing the scale.

The spot size of the old lens F14 - 24 F2.8 looks slightly smaller, but the C-line (red), which has high luminous efficiency in terms of color tone, is smaller in the new lens than in the old lens. The g-line (blue) of the new lens Z14 - 24 F2.8 looks larger at a glance, but it is diffused moderately. Therefore, in normal shooting, it is better to sacrifice the g-line (blue), which has low luminous efficiency, and to have the C-line (red) be dominant, which will improve the resolution.

MTF

The left lens (blue) is the old lens F 14-24 F2.8, and the right lens (red) is the new lens Z 14-24 F2.8.

Maximum Aperture F2.8

Finally, let's review the results of the MTF simulation.

The new lens on the right, the Z14-24F 2.8, is an incredibly powerful ultra-wide-angle zoom lens.

Small Aperture F4.0

The performance of the new lens Z14-24F 2.8 is too high from the opening, so the performance doesn't change even with a small aperture in the sense of a high level.

Conclusion

We have found that the new Z14-24F 2.8 lens is a formidable lens that achieves remarkable miniaturization and even higher performance.

We can see that all the advantages of mirrorless systems have been brought out and achieved by high-dimensional aspheric lens manufacturing technology.

This is an item that you can look forward to filming.

Amazon Product Link
Click here to check prices

NIKON NIKKOR Z 14-24mm F2.8 S

Sample Picture

Please refer to the individual analysis page for the example of 14-24 F2.8.

If you are looking for analysis information on other lenses, please refer to the table of contents page here.

-NIKON