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Writer's pictureTakashi Iwamoto

Nikon Z9 A great camera has come out! !! !! The content is about eyesight and the number of pixels


Evolving camera


I haven't blogged for months for a while.

The caretaker's current location is Nairobi, and he is alive and well.

The reason why I didn't write a blog for a while was that I didn't have the motivation to write a blog, such as location and editing.


I'm a manager who doesn't care about new things, but the Z9 that came out of Nikon this time was so decent that it was too super-class, so I decided to take it up a bit.

From the middle of the story, the relationship between eyesight and monitors has shifted ...


 


The manager who wrote about the reason for using a single-lens reflex camera in the blog I wrote before.

She used a single-lens reflex camera for photography and a Panasonic mirrorless camera for video.


Looking at the performance of the Z9 released by Nikon, I thought that I had to change my thinking so far, so I will introduce it.


I used to use Lumix such as GH5 for movie shooting, because I can shoot with 4K60P and the format size that is easy to use for movies.


Micro Four Thirds is a great advantage for managers who use a lot of telephoto lenses.

Until very recently, I thought the 4K60P was a great performance, but it seems to be a long time ago. I feel the passage of time, or the short life of recent cameras.


Looking at the video performance of the Z9, it far exceeds the specifications of the GH5's 4k60P and 8bit, which means that 8K, 60P and 12bit RAW recording will be possible in the camera in the future firmware upgrade.

I'm surprised that this can be recorded in the camera.

When everything can be done inside the camera, monitors that can record externally will disappear.


Furthermore, it seems to far surpass the autofocus performance, dark autofocus capability, and D6.

If you use the starry sky mode etc., will you focus on EV-8.5? ?? ?? It's too amazing.

The performance of the camera engine and CPU is also 10 times higher than before, so it seems that it is a long time ago that mirrorless cameras exceed the performance of single-lens cameras.


It seems that a PC machine that plays and edits such videos and tremendous power are required.

Regarding this spec, it seems that it is at this stage.


The manager himself was interested in Sony's mirrorless α7S III, but with the announcement of the Nikon Z9, that feeling disappeared somewhere.


Anyway, there is no doubt that it is a monster machine that breaks the current common sense.

This is what most photographers feel.


Furthermore, it is an epoch-making machine that removes the mechanical shutter and adopts a complete electronic shutter.

It is solid, but I feel the strength of Nikon, who is making a leap forward in a place where there is no excitement, to adopt this for professional machines first.


It's strange why Sony and Pana didn't do this first.


There are still advantages to one eye



As a caretaker, I thought that the brightness would be exactly the same as the outside light without a time lag, such as when shooting wild animals, and that even if I kept staring at it, I would be better off with a single eye with a finder screen that would make my eyes tired.

Until this announcement.


However, he feels that he has to change his mind after seeing the stunning performance of the Z9.

In fact, I don't know the truth unless I pick it up and see it.

I'm really looking forward to touching the manager who hasn't got the Z9 yet.


Anyway, Nikon will do it for you.


Panasonic, which can shoot 4K in 2014, has evolved so far in 7 years since the release of GH4.

I think that such evolved monster specs like Z9 will become commonplace in the near future.

The time has come when you can easily shoot high-quality 4K video on your smartphone, something that you never thought of a long time ago.

Whether it's necessary or not.


If you turn it over, there will be a machine with no mechanical shutter, no mechanical part in the camera, mounting accuracy, etc., but in short, when it comes to the body, it can be done with only a box and a base.

In the not too distant future, I don't feel like becoming a commodity like a smartphone.

There are already black magics with high specs and low prices.

From now on, Chinese manufacturers will also enter the market for cheap high-performance cameras.

High-tech technology is also being sucked up by expanding the factory to that side.

Many Pana and Sony have high-tech cameras produced over there, so you can imagine.



Compared to the latest spec, Nikon Z9, the spec of Panasonic GH5 looks like a toy.

Actually, 4K60P is enough for movie shooting.

In fact, I personally think that Full HD 30P and 60i are sufficient.

All you need is the specifications that the client needs.

I think HD is enough for personal viewing.



By the way, the video quality of Z9 is


The resolution of 8K video is 7640x4320, which is 33 million pixels.

Already the same as a photographic pixel.

The gradation is also different for videos, such as 12-bit RAW and video compression methods, so it can't be compared unconditionally, but it's more than JPEG for photos. JPEG is 8-bit.

Pictures of such image quality are continuously displayed at 60 frames per second along with audio.

A total of 16 full high-definition screens, 4 vertically and 4 horizontally!


If a video can take an image that is the same as a photo like this, the significance of taking a photo will change significantly, considering the degeneration of paper media, which is likely to progress further in the future.


When the GH4 came out in 2014, I thought there was a great guy who could shoot 4K.

It is terrifying that 8K will become mainstream in just seven years, the evolution of high-tech.

Isn't it still mainstream?


Even so, 8K, 60P, 12bit RAW, is there such a spec in video?


In the first place, the manager who still thinks that the image quality of DVD is beautiful when viewed on a full HD screen. DVD has SD image quality and the number of pixels is only 720x480.

To save data, the manager himself can watch YouTube with a low image quality of 144 or 240, and set it to 360 when he wants to watch it luxuriously. I rarely use 480.

(In the current situation in Kenya, prepaid cards have become cheaper recently, and 7.4GB is about 200 yen and 90GB is about 1300 yen, which is not stingy.)


Another reason is that YouTube doesn't have much content that you want to see in such high quality.


So, I'm impressed with the 480x720 SD quality DVD that I sometimes watch.

In short, I think it's more about content than image quality.



I considered the relationship between eyesight and monitor resolution


How much eyesight do you need to see 8K video in a proper resolution?


In the first place, Japanese people, is their eyesight so good?

It is also a video screen that keeps changing from moment to moment.

If it's a photo, you spend a lot of time from corner to corner to appreciate it, so there are scenes where high pixels live.

Is that spec necessary for a video that burns an afterimage into my mind?



So, I calculated the relationship between eyesight and screen format


People with a visual acuity of 1.0 say that the Randolt ring and the C mark with a gap used in that visual acuity test can be seen 5 meters away and a gap of 1.454 mm.

This number of 1.454mm means that the viewing angle is 1 minute and 1/60 of 1 degree.

It means that the resolution is 1 arcmin.


Is it 1.5mm in Japan? But this time, I calculated it in 1 minute (') 1.454mm.


A person with a visual acuity of 2.0 can see a gap of 0.727 mm in the Randold ring, which is 5 meters away, for 0.5 minutes, which is half of that.

The highest value of a general vision test.


When I was a student, I think that the number of students who had a visual acuity of 2.0 was in the class.

The caretakers were about 1.2 and 1.5 on the left and right. By the time I went to high school, I had once dropped to 0.3 and 0.4, but I was able to return to my original vision without correction.

I'll blog about how to maintain my eyesight and how to revive.


It seems that there are some people in Kenya, such as Masai, who have about 3.5.

Recently, even such Masai have been trapped in smartphones, so it seems that their eyesight is declining. Nevertheless, their ability to search for animals in the savanna is still far beyond the ability of the caretaker.


Their eyesight becomes very important when shooting wild animals in the savanna.

Wild animals that we can't see are clearly visible to them!



The human eye is structurally similar to a camera.


The human eye has almost the same structure as a digital camera.

There is a crystalline lens and a vitreous body (lens), there is a retina (imaging sensor), an image is formed there, and that information goes to the brain (engine, monitor) by nerves (wiring) and is visible. .. It also has a cornea (protective filter).

Focus is adjusted by tension and looseness of the ciliary muscle, and aperture is adjusted by glow and pupil.


By the way, the specs of the human eye camera are


With the pupil fully open, its diameter (caliber) is 7mm or 8mm.

So the aperture is 7mm, the focal length is 17mm, and the image circle is 24mm (information from the department about a certain YouTube channel and camera).


Theoretically, the larger the aperture, the higher the resolution and resolution.

This is because when light passes through a small slit, it is diffracted at the edge part and a ring (Airy disk) is generated around the point image, so the component as a wave of light interferes and the image quality is improved. Things that do bad things.


Now, let's calculate the resolution to see how much resolution can be achieved assuming that the aperture of the human eye is 7 mm.

The resolution shows how close a double star and two very close stars can be seen separately with an astronomical telescope.


The formula is from the dose limit based on actual measurement

Resolution (″) = 115.8 ÷ aperture (mm)


Applying this to the human eye with a caliber of 7 mm,


Resolution = 115.8 ÷ 7

Resolution = 16.5 (”) = 0.275 (’)


With this resolution, if you replace it with the sight of the Randold ring

1 / 0.275 = 3.64

The visual acuity at the theoretical limit resolution of the human eye is 3.64.


The larger the caliber, the more it can be disassembled.

When the pupil is 8 mm open, 115.8 ÷ 8 = 14.475 (”) = 0.241 (’)

1 / 0.241 = 4.15


I hear that this caliber gets smaller as we get older.

Is it 8mm open for children?

Theoretical limit visual acuity at that aperture, 4.15 Great.

This is a perfect lens with no aberration.


In fact, when the pupil is dark, the brighter it is, the more the pupil closes and the light that reaches the cornea is adjusted. Under the scorching sun, the pupils are quite small and close, so the resolution should be reduced.

For the time being, the eyesight when the pupil is narrowed down to 3 mm


When calculated in the same way, the resolution is 0.64 minutes and the visual acuity is 1.56.


Using this calculation, we can see that there are quite a few smartphone cameras with lenses that do not reach the theoretical resolution and with high pixel sensors.

If you don't think about anything, you'll be fooled into thinking that a high-pixel camera is good because it doesn't involve image quality. Photo data is heavy even though there is no image quality.

Some smartphones claim the number of pixels larger than the sensor size, so if you don't know what you are doing, you can easily be fooled.

I don't know, but there is also the word Buddha, so maybe that's fine.


It is the same as the aberration of the camera, and of course the human eye should have more or less aberration. It seems that the resolution will be higher and you will be able to see better if the pupils are narrowed a little rather than when the pupils are fully opened.

When the aberration is zero, the resolution is highest when the aperture is wide open, but the image quality is improved when the aperture is stopped down a little.



Masai with a visual acuity of 3.5 can distinguish a Randolt ring 5 meters away and a gap of 0.242 mm.

By the way, the criteria for obtaining a Japanese driver's license are omitted in detail, but one eye is 0.3 or more, and the total of both eyes is 0.7 or more.

The resolution of the visual acuity is 4.85 mm at 0.3 and 2.08 mm at 0.7 (the gap between the Randolt rings 5 ​​meters away, respectively).



Now, let's see how much the TV screen can be resolved by the human eye with this resolution.


Full HD TV, 4K TV, 8K TV

The number of people who don't watch TV is increasing recently, so I will describe it as a monitor.

Let's take a look at the monitor size, 50 inches.

Nowadays, the 16: 9 ratio is commonplace, so there's no need to write it down.



The screen size of the 50-inch monitor is 62.3 cm in height and 110.7 cm in width.

If you calculate the pitch of the pixels that enter here in each format


  • In full HD (1080x1920), the size of 1 pixel is 0.57 mm in length and width.

  • With 4K (2160x3840), 0.29 mm

  • 8K (4320x7680), 0.14 mm


The 50-inch monitor is quite large, so it may actually be farther, but it's easy to calculate, so I calculated it with a viewing distance of 2.5 meters.


With a visual acuity of 1.0, the resolution 2.5 meters away is about 0.727 mm, so even a full HD screen with a pitch of 0.57 mm cannot be seen at resolution.

When approaching 1.97 meters, a person with a visual acuity of 1.0 will be able to resolve a 50-inch, full HD screen.


For the time being, when I calculated the visual acuity to resolve a 50-inch full HD screen 2.5 meters away, the visual acuity was 1.3.

With a visual acuity of 1.3, pixels on a 1080x1920 pixel 50-inch full HD screen 2.5 meters away can just be resolved.


Driver's license standard, for a person with a visual acuity of 0.7 to resolve 5 x 0.57 / 2.08 = When approaching 1.10 meters, a 50-inch full HD monitor will not become a resolution event.


In the first place, don't look at the 50-inch screen so close.


4K screen with higher image quality and resolution of 2160x3820 pixels

If you calculate in the same way, the resolution is doubled, so if you double your eyesight, the answer will come out.

Therefore, in order to resolve a 50-inch 4K screen 2.5 meters away, a visual acuity of 2.6 is required.


And at 8K, the visual acuity exceeds the dose limit of 5.2.


The resolution of visual acuity 5.2 is
1 / 5.2 = 0.192 (’) = 11.52 (”)

The caliber required to disassemble this can be found in this formula.

Resolution (″) = 115.8 (″) ÷ aperture (mm)


11.52 = 115.8 / caliber
Caliber = 115.8 / 11.52 = 10.05mm

An optical system with the naked eye with a minimum aperture of 10.05 mm is required.

Someone with such an open pupil, maybe somewhere.

He is not an ordinary human being, if any, but an alien.

How should I calculate the visual acuity and resolution for a vertically long pupil?



A 50-inch 8K monitor seems to be less common.

So, when I searched on the net, there was something called 70 inches, so I calculated it with this.


70 inch screen size, height 87.2 cm, width 154.9 cm

The size of the pixel pitch is incidental, so from full HD


70 inch monitor

  • Full HD 1 pixel size 0.81 mm

  • 4K 0.40 mm

  • 8K 0.20 mm


If you calculate in the same way as above, you will need 3.64 eyesight to resolve a 70-inch 8K TV 2.5 meters away.


It's just equal to the theoretical limit of an eye with a pupil open to 7mm!


Watch an 8k, 70-inch monitor 2.5 meters away.

It may be the ultimate setting that people with the ultimate eyes can finally disassemble.


You don't have to disassemble it separately, I'm sure.

Perhaps the fact that it cannot be decomposed as pixels increases the reality that is the same as the real thing?

From that point of view, does it seem important to increase the number of pixels until the pixels cannot be decomposed?


If a person with a visual acuity of 1.0 has a 70-inch, 8K screen, resolution can be achieved by approaching 69 cm.

Looking at a 70-inch screen as close as 69 cm is impressive.

There is no doubt that the sense of locality will increase.


70 inches seen at that distance, the apparent angle is 64.5 degrees in length, 96.5 degrees in width, 104.2 degrees in diagonal

In terms of the angle of view of the lens, it is equivalent to a full-frame, ultra-wide-angle lens with a focal length of 16 mm.



This can be used as a guide for viewing distance to see 8k screens.

Regardless of the screen size, a person with an 8K screen and a visual acuity of 1.0 will be able to separate the full-size angle of view of 16mm.

That's exactly what the viewfinder image looks like with a 16mm lens attached to a full-frame camera.

If you have a visual acuity of 1.0, you just need to keep a distance from the screen so that the angle of view is the same.

With a 4K monitor, the visual acuity is 1.0, the angle of view is 32 mm, and with full HD, it is 64 mm.

If the visual acuity is 2.0, the angle of view is twice the focal length, and if you can see it at 64 mm, it is just the boundary line of the resolution limit.


If the screen is smaller than this, it cannot be resolved.



By the way, is it meaningful that the resolution is so high that it cannot be resolved?


As I wrote earlier, I think there is no doubt that the realism will come out by increasing the number of pixels and eliminating the graininess.


Personally, for now, I feel that the monitor resolution should be full HD, but once I use a high-pixel monitor, I'm sure I can't go back.


Recently, I'm thinking of introducing a 27-inch 4K monitor for photo editing on a PC, because I can work while looking at a wide range of photos without enlarging it so much to check the focus.

I calculated how close the particles would be. As eyesight 1.0,

The pixel pitch of the 27-inch 4K monitor is 0.157 mm.

0.157 / 1.454 x 5 = 0.540 (m)

It's closer than 54 centimeters and can just be separated.

It looks good as a computer screen on a desk.



Even if you can't resolve, when you compare the FHD and 4K monitor screens, you can feel that the 4K screen has a nice texture without any graininess.

It seems to have a natural texture without sharpening.

However, if the resolution is so high that it is far from the eyesight, it will become slimy and it will be difficult to sharpen it.

On the other hand, the lower the resolution, the better the sharpness, and the sharper and more impressive the image may be.


There aren't many people who can shoot in 8K image quality, and it seems that it's hard to see them as hair growth or pimples.

Beautiful skin mode for portrait photography,

Now that face recognition and eye recognition have become commonplace, automatic skin beautification is likely to become commonplace.


The manager who says that, I've shot various things in 4K and 60P, but I haven't seen the video I shot in 4K quality yet.

Well then, if I was told that I wasn't qualified to speak, until then.

I haven't seen it, so maybe my dreams will spread.

So, what I talked about in this blog is the world of delusions by the manager who has not actually watched it.



 

At the end,


When I do a visual acuity test, I use my eyesight to look at only one point so much that I get tired.

Only one point can be concentrated on humans.

Furthermore, in the examination, if you answer more than half correctly, you will have that visual acuity, so rather than seeing it completely, you can judge the boundary line that looks vague to some extent.

If you try to look at a wide area at once, you will be looking at the whole thing and you will not be able to see the details.

Since the monitor screen usually looks at the whole, and does not focus on one point, the actual eye operation may not be as good as the value of the visual acuity test.

I hear that birds can concentrate on two points at a time, but humans can concentrate and resolve only one point in a narrow range. Very limited.

There is such a mechanism of the human eye that grasps the whole by moving one point with such high resolution, and even a blind spot that can not be seen at all.

Is it necessary to have an ultra-high resolution such as 8K for video for such a poorly performing human eye?


The caretaker still had a lot of doubts.


8K image quality feels like a tremendous over-specification for humans when shooting movies normally.

I think it's a good example of hardware going beyond human specifications.

With this kind of feeling, machines will surpass humans in all fields, despite human abilities.

It feels like we are looking ahead to the times when humans have replaced robots.



Ultra-high pixel video function that is convenient if you have it

8K shooting of super high quality video, I wonder if there are various scenes that I think are necessary.

It seems to be a very lively spec for projecting on a specially large screen such as a movie theater or planetarium.

After that, when cropping and using it, there is a tremendous margin to correct blurring. The whole situation such as soccer and baseball can be handled with a fixed camera. With FHD, you can zoom 4x from that screen.


Black Magic has already released a 12K machine.

The resolution may still increase.

Will the number of pixels increase to the very limit of the wavelength of light?

It seems that it will continue to evolve regardless of the world of manufacturing and human abilities.



Nikon has moved his camera factory overseas.

Although the Z9 is a product made by a Japanese manufacturer, it is already made overseas.

Such a super machine cannot be made in Japan.

Manufacturing technology is pulled out of Japan and leaked overseas.


Japan has continued to develop through manufacturing, and Japan is being watered down.

I felt a little lonely.



 

Somehow, I started writing to talk about the camera, but it ended up talking about eyesight and monitors.


It's a world of self-satisfaction, but I wonder if it's good because I did some research, did some simple calculations, and learned about the limits of human eyesight and the relationship between eyesight and monitor resolution.


I would like to take this opportunity to update my blog again.


Please note that the content is like this, and I will write down what I have come up with.





Thank you for reading this article to the end.


 

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takashi iwamoto rogo white wide
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