BLOG: Katte Kimama

  • Takashi Iwamoto

Shooting of ISS (International Space Station), this time shooting with 3 teleconverters on 500mm f4,

Updated: Aug 11

Blog update after a long time.

The manager updates the blog when he is free.

Please note that it is a blog that writes what you feel when you feel like it, because it is "selfish".


This time, I took pictures of the ISS and the International Space Station, so I will write about that.


 


Shooting of the ISS (International Space Station), which I mentioned in my blog twice before.


Panasonic's GH4 was used for the first ISS shooting, and the lens was a Nikon Ai Nikkor 500mmf4P ED.

Taken at 1400mm with a teleconverter 2x and 1.4x.

The shooting was done with 4K video, and the image was finished by stacking processing.


The second time, I took a still image of the body with the same lens as the Nikon D850.

Taken while Astronaut Maezawa was on board.

This is a normal photo.


And this time for the third time, the body was Nikon D800E, the lens was the upper lens, and the telecon 2x was combined to increase the magnification.


For the time being, the image taken before.



Taken on March 12, 2021



Taken on December 11, 2021



Comparing the above two points, the one shot with GH4 is clearer.

Both points are doubled in pixels.



The smartphone app I see occasionally, the ISS detector, and the reason I shot this time was because the day after I saw the ISS detector was just the best time to see the ISS.

With this app, the ISS (International Space Station) will tell you in detail when and in what direction you can see from your current GPS location.


The ISS is always in orbit, so I don't think it's always visible, but there aren't many days when it's in full bloom.

The best time to see is that the ISS passes high in the sky at just the right time in the evening or morning.

I wrote the same thing before.

The brightness is over -4 mag when it is in full bloom. About Venus when it gets brightest.


The condition is that there is still sunlight over 400 kilometers, illuminating the ISS.

So, you can see the ISS only about an hour after sunset and before sunrise.


The caretaker who is not good at the morning, the only thing that makes me want to shoot is after sunset.

I'm not enthusiastic.


This shooting condition


Clouds in the sky are almost full.

There are gaps here and there, and the starry sky is peeping. The conditions are not very good.

Can you see the ISS?



If you bite 3 teleconverters on 500mm f4, it will be so long



The conditions were not good, but there was a cloud gap in the path of the ISS. I managed to capture the ISS that appeared in such a gap.


Then, the moment the ISS appeared through the gaps in the clouds, I released the shutter and finished it in the photo below.




Same size as pixels and above size.

The total focal length is 2800mm with 2x, 2x and 1.4x in 500mm.

As expected it is 2800 mm.

The photo above has been processed to make it look sharper by raising the shadow to make it easier to see, but it looks blurry.

Since there are 3 teleconverters, it may be quite impossible in terms of the number of lenses.


While the top two images are printed at double the pixel size, despite the fact that they are the same size as the pixels, there is no sense of superiority in terms of image quality. Similarly, when I doubled the pixels and put it out, it was too blurry, so I put it out at the same size.


As you can see, if you put it out under the same conditions and double the pixels.



It's blurry, but it's big and easy to see.



This time, the moon after half a moon is in the sky at the time of shooting.

When shooting the ISS, the exposure and focus were adjusted by shooting this month.


By the way, how big is the moon at 500mm with 3 teleconverters and a combined focal length of 2800mm?

The photo below shows the moon taken with the same optical system without trimming.



Full size 2800mm, no trimming


By the way, the ISS also came out without trimming below.




The ISS can only be seen as large as a grain of rice, even when taken at a super-telephoto of 2800mm.

The white rice grain dot on the upper left of the center is the ISS.



Combining the ISS with the moon and the ISS.

Apparent size, comparison between ISS and moon.



Moon and ISS, composite photo



It is easy to see how big the ISS looks like in the photo above.

The manager himself is convinced. "The ISS is about this size compared to the moon."


In fact, even if the ISS approaches the moon in the sky and comes to this position, the shutter speed will be slow, so either the ISS month will be blurred.

If you raise the sensitivity considerably, can you suppress the blur to the extent that you can see it to some extent?



By the way, the shutter speed for shooting the ISS this time is 1/80 second, and the aperture is synthetic f32.

There is a way to shoot with high sensitivity, but the higher the sensitivity, the lower the image quality.

I want to keep the sensitivity as low as possible for such shooting that uses the full dynamic range.

The image quality is reasonably good even with recent cameras and high sensitivity, but as the sensitivity increases, the dynamic range decreases and the amount of information on the subject continues to decrease.


The ISS moves faster than expected in the sky.

It is moving at a speed of less than 8 kilometers per second and less than 28,000 kilometers per hour.

It is as far as 410 km + above, but its movement seems to be very fast.

That should be it, it goes around the earth in about an hour and a half.



The photo below shows a comparison of the apparent size of the moon based on the ISS standard.


Moon and ISS composition, pixel size



I remember 2001: A Space Odyssey.



I want to shoot with even higher image quality


Somehow, I can't take a clearer picture of the ISS.


A camera with a small pixel pitch, which can take a large picture without optically magnifying it, is superior to such a strongly magnified image.

Since unnecessary lenses such as teleconverters can be minimized and the performance of the lenses can be maximized, it leads to sharper and sharper images.


No, if you want to use existing equipment with the highest magnification and the highest image quality, there is a magnified shooting method!

Yes, it's a magnified photography method that is often used for planetary photography! !! !!

The number of lenses is overwhelmingly smaller and the magnification can be increased compared to the method of clearly capturing Jupiter in another blog, which is a stack of three teleconverters. Aberration should also be suppressed.


The magnifying image method is a method in which the eyepiece of an astronomical telescope is sandwiched between the camera and the lens to achieve a strong magnification.

I'm sure you can take a clear picture of the ISS by taking advantage of the full size!

Such a delusion runs around the manager's head.


The composite focal length taken by Jupiter on the blog is 9500mm (using a 6mm eyepiece).

If you use a 20mm eyepiece, it's just right.


It's a promising method, but the challenge is how long the ISS, which continues to move at high speed over the sky, can be kept in the minimum field of view.


Next time, let's try the magnified shooting method.

The D850 is used to stack 4K video in DX size.


I get excited when I fantasize about how clear an image can be taken.


I have to suppress the overexposure of the heat sink.


Stay tuned for the next ISS shoot!

What time will it be again?





to be continued

 

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Displayed from Japanese to English using Google automatic translation.
Please understand that the meaning may be slightly different.