MINOLTA SONY

The Ultimate Guide to the MINOLTA AF 35mm F1.4 vs SONY Distagon T* FE 35mm F1.4 ZA - Optical Design Value Analysis No.060

This is a performance analysis and review article of the MINOLTA AF 35mm F1.4 vs SONY Distagon T* FE 35mm F1.4 ZA

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.

Overview

In this article, as a comparative analysis of SONY series 35 mm large diameter lens, we will do a comparative analysis of MINOLTA AF 35 mm F1.4, which is the origin, and SONY FE 35 mm F1.4 ZA, which was renewed about 30 years later.

See each article for a detailed analysis of each.

ALSO READ: MINOLTA AF 35 mm F1.4

ALSO READ: SONY Distagon T * FE 35 mm F1.4 ZA

First of all, let's take a quick look at the history of the world's first 35 mm large-aperture F1.4 lens for autofocus, which began with MINOLTA. Now, let's look at the 35 mm F1.4 lens for α camera, starting with the lens released by SONY, which was transferred from Minolta, in order of year of release.

  1. 1987 Minolta AF 35 mm F1.4
  2. 2006 SONY SAL35mm F1.4G (Diverted from Minolta)
  3. 2015 SONY Distagon T*FE 35 mm F1.4 ZA
  4. 2021 Sony FE 35 mm F1.4 gm

(1)The optical system of MINOLTA AF 35 mm was reused as (2)SAL35mm F1.4G even after it was transferred to SONY, and it was from (3)SONY FE 35 mm F1.4 ZA that it was fully renewed.

The full renewal of the (3)SONY FE 35 mm F1.4 ZA for the first time in about 30 years is not only the launch of a new product, but also has another historical meaning.

That is, the SONY FE 35 mm ZA is the world's first full-size mirrorless single-lens 35 mm F1.4 lens.

Note: Strictly speaking, you could say that there is a rangefinder lens.

In short, the purpose of this article is to compare the two "starting lenses" of the 35 mm F1.4 lens, which can be said to be the representative of each company's lens series in recent years, the "origin of autofocus support" and the "origin of mirrorless single lens".

Private Memoirs

MINOLTA AF Lens is the world's first full-scale SLR lens series, but it has a sad history of being sold due to the downsizing of the camera business as a result of an incident.

Although it is a very famous case, it is recorded as an international patent dispute under the name of "Minolta and Honeywell Litigation Case".

There are a lot of full-scale explanatory articles about the incident in the world, so let's look back just a little bit.

Honeywell is an American manufacturer of electronic components. In the 1980s, Honeywell also manufactured electronic components for camera autofocus, which were purchased by Minolta and other companies.

After that, Minolta and other companies left Honeywell to develop their own SLR cameras with an eye to the auto-focusing of SLR cameras. At that time, they were sued for the infringement of Honeywell's patents and ended up paying a settlement of tens of billions of yen.

It's been "rumored" that Minolta has pulled out of the camera business in the aftermath of the settlement.

I often hear the rumor, but did it really lead to the withdrawal? The lawsuit against Honeywell was concluded in 1992, and in 2003, Minolta merged with Konica to form Konica Minolta.

Since it was 2006 when Konica Minolta announced the sale of its camera business, it must have been planned to withdraw from the business when Konica Minolta was born, but it seems that the Honeywell incident did not directly lead to the withdrawal of the business.

I'd like to know the truth about this area. Don't you think there will be a expose book?

The official reason for the sale was announced as "Delay in digitalization" in a word.

Then, I have prepared a link to the actual product to know what Honeywell's patent is.

External Link: Honeywell Patent US3875401

This patent applies for a distance measurement method to realize camera autofocus, and is related to "phase-difference autofocus," a basic distance measurement technology used in single-lens reflex cameras.

Looking at the description and illustrations, it is slightly different from the autofocus mechanism of a single-lens reflex camera, but the scope of rights claimed by the patent refers to the basic part of the invention, and does not necessarily have to be the same as the embodiment, so from a broad perspective, it includes a single-lens reflex camera.

The description of this technology and lawsuit will be long, so I will introduce a book that is explained in detail and easy to understand.

The books I am going to introduce are "Camera and War" and "Domestic Camera Development Story" by the respected late Iwao Ogura.

Unfortunately, "Camera and War" seems to be out of print, but it seems that it is still available at a reasonable price in second hand. I would like you to get it before it becomes a premium price.

By the way, Dr. Iwao Ogura was in charge of analyzing new cameras for many years in the most famous Japanese camera magazine "Asahi Camera", which was regrettably discontinued in 2020. At the same time, he wrote the history of modern camera technology in the form of a book titled "Dr. Ogura's Theory of Photographic Evolution".

This series is compiled in two volumes, the previous "Camera and War" and the following "Domestic Camera Development Story".

As for the domestic camera development story, the used one is already priced at a premium, but there seems to be an on-demand version.

An on-demand version is a form that is printed, bound, and delivered after the order is placed, and you will get a substantially new copy.

A technical discussion of the Honeywell case can be found in The Story of Domestic Camera Development, and the social context and more can be found in Cameras and the War.

By the way, both of them are just great books, and if you profess to be a "camera lover", you must read them.

This is the end of the chat, and let's move on to the main topic, the comparison between MINOLTA AF35mm and SONY 35 mm ZA.

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 above figure shows the optical path of the MINOLTA AF 35 mm F1.4 and SONY FE 35 mm F1.4 ZA.

To make it easier to compare the two lenses, they are drawn with the same scale ratio.

The MINOLTA lens has a long back focus structure for single-lens reflex cameras. It is said to have a retrofocus structure with many concave lenses on the subject side.

On the other hand, the SONY lens has a concave lens on the subject side, but since it is for mirrorless single-lens, there is a margin in the back focus. It also has many concave lenses on the image sensor side, and has a structure similar to a symmetric type with concave lenses on both the subject side and the image sensor side.

The difference in the number of lenses is only two, but if you focus on aspherical lenses, the MINOLTA lens uses only one lens, but the SONY lens has a gorgeous composition of three threatening aspherical lenses.

The SONY lens has a sharp shape that seems to have less aberration, but the MINOLTA lens also has a tight and beautiful shape without waste.

Longitudinal Aberration

Graphs of spherical aberration, image surface curvature, and distortion

Spherical Aberration , Axial Chromatic Aberration

Let's look at the spherical aberration first. The MINOLTA lens is a tasteful and straightforward full collection type, and it seems to have a core in the soft description.

On the other hand, the SONY lens is sharp like a sharpened razor.

I can feel the progress of technology for about 30 years.

It is not an exaggeration to say that the axial chromatic aberration is almost zero for SONY lens, but the amount of MINOLTA lens seems to require a lot of ingenuity when shooting.

Field Curvature

With the MINOLTA lens, I can feel that the field curvature is quite rough around the edge of the screen at the top of the graph, but considering the shallow depth of F1.4, I don't think there is much difference in practical use.

Distortion

The distortion aberration is a slight difference, but the SONY lens seems to be larger. Modern cameras can correct the distortion aberration by image processing, so isn't it corrected with much importance?

The absolute values of both are not extremely large, but they are at a normal level.

Lateral Chromatic Aberration (Magnification Chromatic Aberration)

In lateral chromatic aberrations, as in field curvature, there is a lot of space around the edge of the screen at the top of the graph, but if you don't take a very flat subject, you may be impressed that the MINOLTA lens is doing well.

Transverse Aberrations

(Left)Tangential direction, (Right)Sagittal direction

Let's look at it as Transverse Aberrations.

In the transverse aberration chart, the small aberration of the SONY lens in both sagittal and tangential directions is amazing.

Spot Diagram

Spot Scale 0.3 (Standard)

This is the result of an optical simulation, but first let's look at the spot diagram.

As you saw in the transverse aberration, the spot diagram of the SONY lens is showing a great improvement. The difference is 30 years.

But given the historical context, it's not that MINOLTA lenses are insanely inferior. After MINOLATA introduced the 35 mm F1.4 lens with autofocus, it took a whopping 10 years for other companies to catch up.

There is such a difficult lens specification in 35 mm F1.4.

Spot Scale 0.1 (Detail)

MTF

Maximum Aperture F1.4

Finally, let's look at the results of the MTF simulation.

The SONY lens has shown an improvement that doesn't need any explanation.

Small Aperture F4.0

It is said that the old lens, which has a limit of performance in the open, emphasizes the performance when it is narrowed down, but this MINOLTA lens also seems to show the description which is not inferior to the modern SONY lens when it is narrowed down to F4.

Having said that, the SONY lens seems to have higher characteristics overall even with a small aperture of F4.

Conclusion

Although the SONY FE 35 mm F1.4 ZA lens is slightly larger than the MINOLTA AF 35 mm, it has been found to have an amazing performance improvement.

Can you enjoy analyzing about 30 years of technological progress with your skin?

In addition, MINOLTA AF 35 mm, which has a high historical value, is still used as the lens part of SONY SAL35mm F1.4G, so you can enjoy this historical description even now.

Sample Picture

Example photos are in preparation.

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

-MINOLTA, SONY
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