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Writer's picture岩本貴志

Jupiter, planetary photography with a Goyon (500mmf4) telephoto lens, part 3


Welcome to the blog of a photographer based in Nairobi, Africa.

This time I photographed the planets, I took pictures of Jupiter and Saturn after a long time, so I will post them.



Pointed the telephoto lens at Jupiter for the first time in a while


I tried to focus the spotfinder firmly on the distant view of the ground, but with this much magnification, it was difficult to get it into my field of view, and it did not come into my field of view.



 


Recently, the number of past blogs that photographed Jupiter with a Goyon telephoto lens has increased. I wanted to take pictures of Jupiter again, thinking that there are people taking pictures of Jupiter.

So I decided to shoot Jupiter for the first time in a while, even though the autumn nights are long here in Kenya and the nights are not particularly long.


The night sky of Nairobi, I think, is better than Japan, but there are not many days when it is stable.



Recommendations for visual observation with a telescope


When Jupiter and Saturn shine in the night sky, my heart dances and I want to look through a telescope.

It is a planetary image that can be beautifully finished in a photograph, but the planetary image seen directly through the telescope and eyepiece is also exceptional.

I am moved every time I see it.

Rather than looking at the virtual image displayed on the LCD screen, it is just the real thing.

The raw light that has flown all the way through space is now focused on your eyeballs.

This applies not only to planets, but to all the stars that shine in the night sky.

The raw light is still exceptional!

I can feel the positive energy from the universe being absorbed into my body through my eyes.



When the telescope is focused on Jupiter, the four Galilean moons around Jupiter are clearly visible in the field of view.

Since the brightness difference between the Galilean satellites and the surface of Jupiter is large, one of them will be brighter or darker in the photograph, but both can be seen clearly and well in the telescope image.

The field of view is also wide, and if you concentrate on one point, you can see details anywhere.

Such impressions can only be experienced by directly looking through the telescope.


I aim my camera at the planets in the hope that I can convey that feeling to a third party.


By all means, I recommend that you take a look at the raw light through a telescope.

This is the manager's story.

A telescope with an aperture of about 8 cm is quite impressive.


Each person feels differently.



Well now, the main topic Jupiter shooting


This time, the seeing at the time of shooting was not so good, but I think the resolution has improved considerably compared to before.


As before, the optical system uses Nikon's manual telephoto lens Ais Nikkor 500mm f4P.

Of course, even though the 500mm is super-telephoto, it's not enough to use a teleconverter to shoot planets.

That's why I used the magnified photography method.

I blogged about it in detail earlier.



In the magnified shooting method, the lower adapter is sandwiched between the telephoto lens and the camera to increase the magnification.

Inside the tube is the eyepiece of the telescope.

Mechanically, instead of looking through a telescope, the image is focused on the focal plane, and instead of the eye, it is focused on the camera's sensor.

Top, bottom, left and right are reversed.


While we're at it, I'd like to tell you a little about the equipment I use, along with some old stories.



Enlarged shooting adapter

Accommodates NPL6mm, a magnifying photography adapter useful for planetary photography



The lower left eye cap and other decorative rings are removed because they hit the enlargement adapter.



A magnifying adapter for attaching an eyepiece between a telephoto lens (telescope) and a camera.

The focal length of the main lens can be expanded many times, which is quite useful for planetary photography.


A long time ago, when I was in high school, I used to buy this magnifying adapter for the 30-kilometer round trip to save on train fares.

I remember the telescope shop owner serving me a warm cup of tea, saying, "Thank you for your hard work!"



It looks like this when disassembled


lens side on the left



The eyepiece in the photo is 20mm, but this time I used a 6mm focal length.

A while ago, when I purchased a Vixen telescope, it came with an eyepiece.


Including the photo below, new Vixen eyepieces, Vixen's friends and drinking buddies kindly received.

Thank you for letting me use it.



Old and new eyepieces 20mm, 5mm



Compared to the new eyepieces and the old ones, the performance is so good that you can see at a glance that it is easier to see and there is less aberration.

The telescope and eyepiece optics and coatings are new and more sophisticated.


The two K.20mm and Or.5mm lenses in the front of the photo above are the eyepieces that came with the set I bought my telescope a long time ago.


The lens diameter of the peephole, such as the high-magnification eyepiece Or5mm on the right front, is only about 4mm, and the eye must be brought close enough to touch the eyepiece. The telescope I was using was an achromatic refractor, aperture D102mm, focal length f1000mm, and this eyepiece was used for observing and photographing planets such as Jupiter and Saturn at a magnification of 200x.


When I peeked at it, I found that there was quite a bit of chromatic aberration from the eyepiece lens.

New eyepiece, easy to see, bright and clear.

If you compare the size of the peep hole between Or5mm and SLV5mm, you will be able to understand the difference.



telephoto lens instead of telescope


Astronomical telescopes and photographic telephoto lenses have different purposes, but they are the same in terms of focusing.

However, since it is not dedicated to usability, some ingenuity is required.


A telephoto lens that can be used with magnified photography like a telescope must have a mechanical focus adjustment and a certain distance from the rear end of the lens to the focal point.

Recent mirrorless lenses can't be used because they focus immediately from the rear end of the lens and cannot be focused at infinity.

Magnification photography is limited to single-lens reflex lenses.


I use the rear cap to attach the adapter behind my Nikon telephoto lens.

Simply cut out a 36.4mm hole.




Vixen and Super Polaris equatorial are used for tracking.


This equatorial mount has been used by the manager since he was in the 5th grade of elementary school.



This Vixen Super Polaris equatorial mount is still often seen on Yahoo!


It's been nearly 40 years since its release, but it doesn't move. Fine adjustments such as gear engagement can be easily done with a hexagonal wrench, and grease up can be done easily.

With metal parts, maintenance such as greasing can be done, so there are almost no broken elements. Specifications that can be used forever as long as it is not dropped or given a strong impact.


It is very convenient because it has a manual handle and fine movement around the entire circumference for both right ascension and declination. Worm wheel, 144 teeth gear.

It also has a scale ring for right ascension and declination, which are omitted these days. If there is this, the manager's tension rises.

The numbers and scale are engraved so you don't have to worry about them rubbing off.

The declination axis has 2 degree intervals, and the right ascension axis has a vernier scale that can be read to the nearest 1 minute.


Although it is necessary to illuminate it with light, it is very useful when trying to find dark nebulae and star clusters. These days, automatic introduction is common, but it's quite easy to reach the target celestial body while manually tracing the star map.


A map of the stars is being created in my head.


Furthermore, by removing the declination axis, it can also be used as pota red.


Recently, I often think that it is a famous equatorial mount considering that it is a mass-produced machine for the general public and the price is cheap.


For those who want a new equatorial mount, we recommend this product at a reasonable price.

However, it must have a right ascension motor drive and, of course, must work properly.


Authentic, made in Japan at the time of the bubble era, with a 5-year warranty at the time.

Since there is no unreasonable cost reduction, there are fewer troubles than recent foreign-made products, and it may be used for a long time.


Please understand that it is the manager's own dogmatic decision.




Well, the picture below is what I took and finished this time.

The streaks and belts showed finer shading than the previous image of Jupiter.


Jupiter statue this time



Jupiter statue on October 7th.

The atmosphere in the sky and the seeing weren't that good, but Dietel came out so far.

With a 500mm telephoto lens with an aperture of 125mm and the best viewing, how much detail can be captured?


Nikon's manual 500mm telephoto lens, this is also an old telephoto lens, but it captures well even when zooming in on planets, so I'm afraid of its hidden resolution.



For shooting, I used Panasonic GH4 to shoot 4K video for 1 minute and 30 seconds.

  • Sensitivity: ISO 400

  • Open f4.0

  • Shutter speed 1/15 second,

Since it was shot at 30P, 2 frames will be 1 frame.

90 seconds at 15 frames per second, so a total of 1350 frames of information


As usual, RegiStax6 is used for image processing,

This time, I searched the net for software that could be used for astronomical image processing, and tried using a software called PIPP, but it didn't work well because it skipped tones.


I think the setting was bad, but I gave up using it this time, and used only RegiStax6 and Photoshop.


The recorded videos are stacked with RegiStax6.

I changed the Wavelet settings, exported several images, and finally finished by compositing in Photoshop.



Jupiter image after a few days


Image of Jupiter on October 12th.

On this day, I took several pictures at intervals so that I could see the rotation of Jupiter.

Sometimes the seeing gets better, but it doesn't last very long.


The seeing was basically worse than on October 7, but the moon Europa and even the Jupiter surface reflected Europa's shadow.


The shadow of the moon Europa is projected on Jupiter's surface at a fairly distant position, even though the sun should be hitting it almost straight on.


Europa may be farther from Jupiter than it appears in the photo.


Europa and the shadow of Europa illuminated on Jupiter's surface



As for the image, the brightness of Jupiter itself and Europa are very different, so the image is processed so that the brightness is the same.


The Galilean moons orbit Jupiter in the order Io, Europa, Ganymede, and Callisto.

Europa is the second from the inside, the orbital radius is 671,000 km, and the diameter of Jupiter is 143,000 km, so it is 4.7 times the diameter of Jupiter, so it is closer to the earth from the main body of Jupiter.

In the photo, it looks very close to Jupiter, but it is quite far away, and in reality it is quite close to the Earth. Now I'm satisfied with the position of the shadow and the satellite.




The highest quality image of Jupiter of the day


The highest quality image of Jupiter of the day, 32 minutes after the above photo



The image of Jupiter above was captured when the wind eased and the seeing was good.

Even the fine patterns of stripes and obi came to the fore.

By the way, the part where the stripes are dark and the part where the band is light.



In just 32 minutes, the position of the Great Red Spot has moved significantly, indicating the speed of its rotation.

The rotation period of Jupiter is very short, only 9 hours and 55 minutes, and the position of the Great Red Spot is also moving.


The moon Europa also has a very fast orbital period due to Jupiter's enormous gravity, and the change in position can be seen after 30 minutes.



In the sky over Nairobi, the seeing changed quite drastically, and after that the seeing deteriorated greatly.




I put the earth in front of Jupiter so that the size of Jupiter is easy to understand

The size of the Earth is so large that it fits two or three pieces inside the Great Red Spot.


Jupiter's diameter is more than 22 times that of Earth, so when you put them side by side, it's huge!





Stellar Navigator 95 still in use


I learned about the positions of the Galileo satellites by simulating them with the Stella Navigator 95.

It's a fairly old software, and it's still in active use for shooting composition settings and comet launch calculations.



If you enter the same date and time in Stella Navigator 95


The graphics of Stella Navigator 95 will tell you like this.



One of the Galilean satellites, Ganymede, is also near the outer edge of Europa.

In the simulation, the Great Red Spot is also appearing from the left, but is it a coincidence?



"Come on, how about updating the software from 27 years ago?"

"It's enough, so it's still good for now."


The material desires that occur in Japan are almost non-existent in Nairobi.

I'm sure it's because I don't fall into the trap of various commercials.



Jupiter's overview part of the screen, the number of Jupiter's moons in Stellar Navigator 95 is 16, and if you look at Wikipedia now, it's 80 including small moons.

Don't feel the times



Sized to fit Ganymede


Europa and Ganymede



Naturally, the appearance of Ganymede on the simulated street.

Its diameter is 1.7 times that of Europa, which makes it appear larger in photographs.

Ganymede is the largest satellite in the solar system and has a diameter of 5262 km, less than half the size of Earth.

Larger than Mercury, but less massive.




Processing does not go well with HD image quality with RegiStax6


This time, for the first time, I converted it to AVI with a size of 1920x1080 and processed it with RegiStax6.

For some reason, the grain becomes rough.

I don't know the reason yet.


Until now, RegiStax6 did not accept FHD processing, so I gave up, but when I learned that stacking processing can be performed by deleting audio information, I tried it, but the image quality per pixel deteriorated.


The same picture as the above picture at 19:55 on October 12th was converted to FHD size, but the image quality is clearly poor.


I know that this RegiStax6, high-performance free software, will handle complex and strange things, but I still don't know what it is and how it is handled.

For the time being, it seems to be a way to try various things until you get good results.




Incidentally, the image of Saturn overtaken by Jupiter two years ago



The details of the wheel are messed up.

I'm not very good at it.

I'm thinking of replacing the photo when it's a little cleaner.



 

A few days later, when I played around with the stacking processing numbers, the resolution went up.

The photo below is the finished product.


Saturn image with north facing up



The messy feeling is almost gone.


The changed setting is the Set Alignpoint

  1. Minimum distance between minimum 10

  2. Min distance from edge Lo minimum 0

  3. Nunber of Alignpoints Maximum rightmost graph



RegiStax6 The changes on the editing screen are as follows



In the settings, I increased the stacking alignment points as much as possible.


The default setting has few alignment points, and the process finishes quickly, but the accuracy is not enough, and it seems that the stacking will be misaligned, such as the rings of Saturn being cut off.


If you change the settings in the above figure and increase the stacking points, the processing time will be very long, but you will be able to perform highly accurate stacking and the resolution of the finished image will increase.


The second picture of Saturn is the one I finished by tinkering with various things.

Is it chromatic aberration that makes the color of the ring blue?


I'm going to explore various ways to improve the image quality.



In the next issue, I plan to take up a series of photographs taken when Jupiter's moon Io passed through the plane of Jupiter.





Thank you for staying with us until the end.


 

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