BLOG: Katte Kimama

  • Takashi Iwamoto

Deep digging old lens, Nikon 50mm f1.2, relationship between aperture and star image (from f1.2 maxi

This time, I was wondering whether to add to the 50mmf1.2 review blog I wrote before.

However, this lens is no longer a current lens, and there are many sample photos, so I decided to put together a new blog.

I set the Southern Cross near the center and compared and verified the change in the image, using as an example a photograph of a star field taken by sequentially changing the aperture from the maximum aperture of f1.2 to the minimum aperture of f16.


  1. 50mmf1.2 manual lens that I still use often

  2. As automation evolves, do we no longer need techniques?

  3. Africa, Kenya's best-selling camera

  4. Comparing changes in aperture and image quality in starfield photography

  5. First, I lined up examples of no trimming from the maximum f1.2 to the minimum aperture of 16.

  6. Compare examples

  7. Nikon verifies the resolution of 50mmf1.2 open

  8. Screen, magnified image of long edge

  9. If it is up to APSC size, f2.0 seems to be enough.

  10. Strange vignetting in the center near the opening

  11. as a summary


50mmf1.2 manual lens that I still use often

This old lens, Ais50mmf1.2, is an old manual lens but works well.

In terms of image quality, flares are easy to come out and it is not as good as recent lenses, but lines are thin, unique color development and bokeh, and tasteful depiction.

It may be one of the lenses that the manager uses the most.

A novel design that you wouldn't believe is a camera and lens from 40 years ago!?

I still think that the combination of F3 and this 50mm, including the body, is the coolest design.

This F3T was bought second hand at a camera shop in Nakano 30 years ago.

As automation evolves, do we no longer need techniques?

A storm of automation is blowing all over the world.

The camera industry is no exception, and single-lens cameras have become mirrorless.

Nikon says it will stop developing SLR cameras.

Autofocus that evolves day by day.

Image stabilization that is becoming more and more efficient.

A camera that captures the subject.

From corner to corner of the screen, people, animals, and even birds keep focusing on their eyes. Just amazing.

Did photographers no longer have to think about anything technically?

If you have the strength to hold the camera, even small children can easily take in-focus pictures.

It's that kind of time.

To be honest, I don't think it's necessary to take pictures as a hobby.

You should be able to shoot with a camera that you can enjoy yourself.

There are plenty of old cameras on the used market.

Even now, you can still enjoy taking photos with your old lenses and shooting them with film.

Well, film is tough on your wallet.

Even so, I'm really sad that Nikon will stop making single-lens reflex cameras.

The manager, who has been using Nikon cameras for a long time, has a strong attachment to Nikon. That's all, I'm going to write it a little dry.


Africa, Kenya's best-selling camera

Currently, the manager lives in the Republic of Kenya.

There are several camera shops in the capital, Nairobi.

Most of the cameras sold are Canon. There are Sony and Pana, but there are many Canons. Unfortunately, I don't see many Nikons.

Recently, Nikon services and shops have expanded to Nairobi.

However, other than that, the only cameras lined up in electronics stores and camera specialty stores are Canon.

Nikon/Micro Four Thirds I'm looking for a mount adapter with electronic contacts, but I can't find one, although most Canon ones are in stock.

Many of the cameras you still see in stores are single-lens reflex cameras rather than mirrorless cameras.

Canon, which has a factory in Japan, and the low-priced single-lens camera are also made in Japan, and the "MADE IN JAPAN" is clearly printed under the body. That alone is great brand power.

There are many customers who buy just for that.

So, in Kenya, I feel that low-priced single-lens reflex cameras made in Japan are selling well.

Nikon has moved its factories overseas from Japan and even stopped making low-end SLR cameras. Canon does the exact opposite.

Single-lens reflex cameras still have many advantages.

No time lag for single-lens viewfinders, no matter how cheap the cameras are! In that respect, it is more advantageous than high-end mirrorless.

In order to keep moving objects in the viewfinder, a low-priced SLR is the winner.

All single-lens reflex cameras and LCDs can be used in the same way as mirrorless cameras.

Another big problem with mirrorless cameras is the battery issue.

Expensive lithium battery, one small battery costs nearly 10,000 yen!

Rapid increase in demand for lithium due to EV vehicles, lithium batteries, likely to become higher in the future.

With a single-lens reflex camera like that, you don't have to buy a spare, and as long as it's fully charged, you can easily carry it for a whole day.

If it's a mirrorless camera, it's a little lonely with just one.

If you buy a camera that costs about 50,000 yen and have a spare battery of 10,000 yen, you will be hesitant.

Once at a Nikon shop in Nairobi, I was able to touch a mirrorless Zfc for a while.

I thought the design was pretty good.

The finder time lag is surprisingly large.

If you hold your hand over the lens and wave it up and down quickly, there is a time lag that you can see when your hand leaves the screen.

With this, it would be difficult to follow the movement of a dragonfly that perched on the tip of the grass swaying in the wind. Unfortunately, I felt that it was not a camera that could be advanced by people.

As a Nikon fan, I'm disappointed.

The manager was very skeptical about the discontinuation of the D3000 series and D5000 series.

I was surprised that even the D500, a high-performance APS single lens that I had been interested in, was stopped.

I'm sure there are some tough things going on.

Oh, the story was a little too much.

With the flow, I thought it would be a story about stars, but the story went in a different direction.


Comparing changes in aperture and image quality in starfield photography

This time, in order to see the rendering performance of the 50mmf1.2, I compared shooting starry skies from the widest aperture to the minimum aperture.

How old lenses can compete with the latest lenses?

However, I don't have a new lens to compare with, so I haven't compared.

The example of this time is a star field photograph taken almost centering on the Southern Cross (it is the southern constellation, but it will be unified with the Southern Cross).

With Nikkor 50mmf1.2, I compared shooting from the maximum aperture of f1.2 to the minimum aperture of f16.

The exposure was standardized at 30 seconds, and the ISO was changed to ISO200 at the maximum aperture of f1.2 and ISO25600 at the minimum aperture of f16 according to the change of the aperture, corresponding to the change in brightness due to the aperture.

ISO settings, f1.2 and f1.4 are slightly less accurate.

The exposure was 30 seconds, and tracking shots were taken with Kenko Tokina's Pota-red and Skymemo to suppress flow due to diurnal motion.

ISO 12800 at f11 and ISO 25600 at f16 are +1 and +2 on the Nikon D800E sensitivity settings.

There is a lot of noise, the dynamic range is narrow, and the white balance is quite fuzzy.

I also have the new and current model D850 at hand, but mosaic noise stands out when zoomed in.

I use the D800E, which has better image quality than that.

High pixel count does not mean good image quality.

In this example, I would like you to see how the D800E responds to different ISO changes, and what the capabilities of the camera 10 years ago were.

First, I lined up examples of no trimming from the maximum f1.2 to the minimum aperture of 16.

At the maximum f/1.2, the amount of peripheral illumination drops considerably.

The bright star in the center is quite stubby and voluminous.

I can't use this for astrophotography.

Just looking at this, it's a shabby lens with poor performance.

Even with f1.4 and half stop, the situation does not change much although it improves somewhat.

The periphery still flows in a ring.

When this lens is stopped down to f2.0, compared to f1.2 and f1.4, it looks sharp like a different lens.

At first glance, most of the stars are point images.

Peripheral light falloff is still quite noticeable.

f2.8, aperture setting often used in astrophotography.

What is the best balance between sensitivity and exposure?

If you don't have an equatorial mount, this is usually the setting.

The most used aperture setting for starry skies.

The surrounding area becomes quite dark.

When I stopped down to f4.0, the peripheral light falloff was considerably reduced and almost disappeared.

The star looks like a small point image to the periphery.

Aperture f5.6, highest image quality? The peripheral light falloff has become almost invisible.

Even the stars are tiny point images all the way to the corners.

Aperture value of f5.6, which I often used for normal shooting where resolution is required, is the best image quality.

When I compared the shots this time, I confirmed that the image quality was actually good, and I was convinced.

I can hardly see the difference from f5.6, but the noise increased by one step and it became dirty.

I don't see any merit in terms of image quality, and I don't stop down to f8 for starfield photography.

At f11, the color changed to magenta, and the white balance became less relevant.

It's almost impossible to stop down like this when shooting stars.

I don't see any advantage of squeezing.

Minimum aperture f16 of 50mmf1.2 and D800E highest sensitivity ISO25600.

Aside from the image quality, I thought that the image quality would drop more due to diffraction, but it doesn't seem to drop that much.

Don't you know it's this size?

Rather than increasing the sensitivity, is it just that the shadows have lost their tightness and become rougher?

I wonder if it's like that.

There is no image quality that can be said about the lens anymore.


Compare examples

First of all, what I would like you to compare with the above example is the decrease in peripheral light amount of the lens.

Around f/1.2 and f/1.4, the surroundings are extremely depressed.

Even at f2.8, there is a clear drop at the extreme edges, but at f4.0, the drop becomes less noticeable, and at f5.6, it becomes almost flat across the entire frame.

The lower part of the image of the shooting location looks bright, but it is light pollution caused by a private house.

The star image is quite bulky even in the center near the maximum aperture, but it tightens up at once when stopped down to f2.0.

The highest image quality is f5.6, the amount of peripheral illumination is almost non-existent, and the star image is the smallest point image from the center to the edge of the screen.

The maximum ISO sensitivity of the D800E is ISO6400, and above that is +1 and +2.

The maximum sensitivity is +2, which is equivalent to ISO25600, which is two steps higher.

All camera settings other than ISO are the same.

All the settings such as the tone that was adjusted when producing the image are also unified.

The next thing I would like you to see is the wide open image quality.


Nikon verifies the resolution of 50mmf1.2 open

Next, I will expand and verify the same example as above.

First of all, from the image quality around the short side of the screen.

The star with the yellow arrow below the photo.

Once upon a time, Johann Bayer, who created a constellation by connecting stars shining in the sky, set it as one of the stars in the constellation Centaurus.

In reality, it is a star cluster made up of countless stars.

First, expand and verify this part.

Magnify this Omega star cluster and verify the resolution of the lens

The image below shows the Omega cluster, the part indicated by the yellow arrow, magnified to 200% pixels.

Omega is the brightest and largest globular cluster in the sky.

By the way, to the left of the bright star shining on the left of the Southern Cross, the arrow indicates Alpha Centauri. It is 4.3 years away at the speed of light.

For this article, it doesn't really matter.

I was surprised that the star image was so sharp at the maximum aperture of f1.2

From the center of the wide-open f1.2 screen to the edges of the short sides, the star images are a little blurry, but they are close to dots, demonstrating the excellence of this lens.

In the Omega cluster, the peripheral stars are also separated.

Even at the maximum f/1.2, you can take beautiful pictures such as portraits because the core is solid.

The photo below was taken by focusing on this part at f2.8

The ISO is 800, so noise increases, but the star image is sharper by stopping down by 2 and a half stops.

The red and blue fringes around the stars can be removed in post-processing, but such post-processing is not done in this example.

Even with the maximum aperture of f1.2, the image is reasonably sharp from the center to the edge of the short side.

By the way, how far outside the screen is reflected?


Screen, magnified image of long edge

Next, verify the image quality around the long side of the screen.

The location is the pink arrow in the example above, jumping two steps, and the area surrounded by the square on the right side of the screen.

I arranged the Aether Carinae Nebula part from f1.2 maximum aperture to f16 minimum aperture at the same pixel size.

Open f1.2, Ulyaryalya! , the stars grew wings.