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Review: Kenko SKYMEMO S Equatorial Mount Star Tracker

Updated: Jul 7, 2020

(in a plain, non-too-technical wording…)

Lately I have gotten quite a high number of emails and messages from photographers all around the globe asking for details on how I do my artworks in general, and Astrophotography in particular. I reckoned that the least that I can do is to write in general lines regarding brilliant Astrophotography gear that I use made by Kenko, Tokina and Hoya. This is hence the first in a series of articles that I dedicate to the subject.

As always, I am happy to answer questions in regards to any of the info supplied over here. Write to me to or visit my site on to get much more info or to send direct messages in the “contact us” section. Here for your inquiries!

A Few Words:

We are going to cut the boring too-technical language out of this space and leave here only the necessary info that I am certain to be more useful and readable for professionals and enthusiasts alike. This was always my way, let alone that Astrophotography can take people down the hill very fast as this genre has WAY TOO MANY words that can kill you of boredom!

This has been for quite a while since I wanted to write a thorough review regarding an Equatorial Mount (or a Star Tracking Mount, if you will) that I have been using when going out to my Astrophotography sessions, and/or delivering workshops in this genre (or niche) of photography. 2020 has started with a Pandemic and forced the world to get inside the homes and close the doors behind. The lock-down made Astrophotography more prevalent and the reactions to my artworks were not too slaggy to arrive in. A bit fast-forward, here in my home-country New Zealand we have managed to eliminate the Coronavirus in all parts of the country. But still, there are continuing restrictions in all the other parts of the world, and perhaps this article will create some great ideas for you to spend time with your cameras during the lock-down, or even afterwards, when everything is going to open up as ever before.

Diving in:

I assume that most of the readers here are pretty much well aware of the Exposure Triangle (Aperture, Shutter Speed and ISO), and actually deal in Astrophotography as a secondary niche to their primary one. However, just to make sure that for those photographers who are new to the genre, I would like to give some quick introduction to what Equatorial Mount means. Very quick.

Picture 1: Earth Axis Tilt (Credit: Dennis Nilsson, NASA)

Equatorial Mount:

Down here, on Earth, it is very hard to notice it, but we are actually all standing on a seedy vehicle. Planet Earth is constantly moving, rotating around an axis. All the planets around the Sun are moving almost at the same plane, the same circle. Our planet has a tilt of 23.5 degrees (also called “Obliquity”).

That tilt character was caused billions of years ago by another planet that collided onto our Planet. The impact had been so immense that it led to tilting our planet in 23.5 degrees to its original state. Some research suggests that the materials that had been ejected from both planets by the impact created our Moon.

Now, actually, this unique tilt creates the opposite seasons of the year. If we, say, live at the Southern Hemisphere for example – countries like New Zealand and Australia – when our hemisphere is facing to the Sun during September to December, that creates our Summertime. During those months, the opposite hemisphere is not facing to the Sun and hence the living creatures on that area of Earth will experience their Wintertime. Without the tilt, we would not have seasons at all, and temperatures on our planet would be (probably) constant in certain altitudes all year long.

So why does this info matter to Astrophotography?

When we take photos of the night sky, we have to consider the tilt because it lets different areas on Earth to view different star groups (also called “Constellations”) in different areas of the sky. The best example that every person may relate to is the Northern Star (called “Polaris”). This is a very bright star that our counterparts up there at the Northern Hemisphere may view every night and get an easy clue in regard to where the north is located. As opposed to the latter, we, at the Southern Hemisphere, do not see Polaris, ever!

As mentioned above, we are standing on an amazingly fast vehicle. The night sky is not only changing every month – it is changing by the day! So, what are the contributors for those fast changes in the night? Why people in Cyprus, Iran, Florida or Fiji see different stars and different directions of the same stars at the very same moment?

Here are the reasons:

As mentioned, Earth’s tilt (obliquity)

Earth’s rotation around its axis (at the picture above look at the “Celestial Equator”)

Earth position on the plane that circulates/orbiting around the Sun along the year (at the picture above look at the “Ecliptic”)

The position of the planets of our solar system along the year.

The position of the Moon along the month and year: the Moon goes round planet Earth and complete one cycle every 29.5 days.

All the above are cycles. In this salad we need to add Moon’s cycle to Earth’s cycle around its axis, and Earth’s celestial cycle around the Sun, and then you get some real, good, fat, big headache! Suddenly we get it - It is all moving so fast and there is no one moment where we stand still.


To make some sense in this starry-night and moon helter-skelter caused by the constant movement of the night-sky players, you have the options to either invest some good time in reading about Astrology (which is an amazing subject), or to actually be used by devices that are built on the science behind it all.

Kenko from Japan makes such professional device. The Skymemo S, compared to other impressive devices that are meant to load very heavy telescopes on them, is actually much smaller in measurements. But do not give this smaller size to impress you any less! This Kenko beast can load up to 5 kilograms (11 lb) of professional photography gear: If you reckon that this means nothing, allow me just to illuminate what this really is with the gear that I can mount:

1) Nikon D810 (0.98Kg/2.15 lb)

2) Nikon D850 (1.005Kg/2.22 lb)

3) Sony α7R IV (0.665Kg/1.46 lb)

4) Pentax 645z (1.555Kg/3.43 lb)

5) Nikkor AF-S 500mm f/5.6E lens (1.460Kg/3.20 lb)

Such heavy gear and lenses, combined, are well below the 5Kg mark that the Skymemo S can bear on. As a professional photographer owning heavy weight gear, I am absolutely impressed. I have seen many of my workshop participants who are regarding themselves as “heavy enthusiast photographers” coming along with much lighter gear.

Night Sky and Trade off

Shooting the night sky is essentially shooting in low light. The so-called “walk in the park” that we, photographers, feel while shooting at the studio surrounded by artificial lights or alternatively while out and about snapping models or newly weds is totally non-existent here! I suppose that every photographer reading this article understands that in low light the exposure needs to be treated with shifting up of the ISO and shutter speed in order to compensate on the limitations that the lenses have, especially where the widest f stops are sitting at f/3.5 (or worse).

When we set the exposure and take the shot, we genuinely expect to get the glorified Milky-Way Galaxy just immediately when the shot ended. More often than not, we won’t be able to get the desirable result. If we decided to shift up the ISO to a significant stop, like 6400, 8000 or ridiculously more than that, we would face with flat frame that either (or both) washed out the stars or made so much noise that it is hard to understand where the stars are and where the noise takes control. The below photo and the next one are made using ISO 3200 and ISO 6400, respectively.

When we go on to the other way – meaning, extending the exposure time and using more rational ISO stops – we will actually get a cleaner frame out of it, however, the price we pay now will be shown as star trails, instead of actually yielding pin point, distinguishable dots!

For those who are after star trail photography, this option is the best and to be honest – they do not really need any other gear. However, if you are after showing your clients the Milky-Way or get even into the deep space photography using lenses of at least 400mm, then such long shutter speeds will make your life unbearable.

Since everything around us up there in the sky seems to move, and we stand still with our cameras mounted on our tripods, the above options are the trade-off play we play in here: we need to give-up either the clean ISO or the shutter speed. As shown in the two examples above, in any case, the results will not be both clean and pin-point sharp!

But, then the Skymemo S comes into the picture!

How does Skymemo S do its job?

This device changes all the trade-off rules I illustrated above! Skymemo S lets my cameras and the attached heavy lenses to track the stars by constantly rotating the movement of the camera (and the lens, of course) at the opposite direction to the rotation of planet Earth around its axis.

If you are confused, then don’t be. In simple words this means that Skymemo S gives my cameras the ability to lock on to a certain star, constellation or even the whole sky dome at the VERY SAME PACE that our planet moves. The result is a sharper, having much more contrast, and cleaner to anything that I could ever get should I continued shooting in the static options mentioned earlier.

With the Skymemo S I turn the ISO as low as 200 or 400 and lets the shutter speed to go for a long time, sometimes even for minutes. If before, when shooting with my camera mounted on a regular tripod, I got star trails because of the long exposure times, now - thanks to the Skymemo S rotational movement, the star trails are completely gone and there are pin point dots scattering the frame. The light-to-noise ratio is dramatically decreased, and I get the desirable results with less shots and less time to spend in the cold nights out, or on the computer afterwards.

What are the alternatives?

Well, if you read this article you may probably ask why not using the “500 Rule”, “600 Rule” etc., or simply take dozens or even hundreds of very short shots, bias frames, dark frames, flat frames, dark flat frames etc. and then spend the evening on the computer to perfect the result.

Locking on Jupiter @500mm focal length, camera on my red Kenko Skymemo S equatorial mount system

I can answer that the work can of course be done using such laborious way; however, these ways have never been as good, as sharp, as easy, and as ‘constrasty’ to those made through this star tracker device. Some long time ago, while I was still using high ISO exposures, I simply created frames with so much noise. Back then, the editing work the bias, black and flats frames either took too much valuable details out of the frame. In other times, it simply could not cope with all noise appropriately. The problem was even greater when I shot with APS-C cameras, because the light-to-noise ratio in those cropped-sensor cameras was much worse than the already noisy results of the full frame cameras. The Skymemo S is genuinely a wonderful companion to my Astrophotography work.

Going back in time, when I purchased my Skymemo S and started using it, I was pretty much in shock with how drastic the results could improve. I was (still am) not a dedicated Astrophotographer. I indeed deal with professional photography in many genres, but when I got into the Astro genre I felt like I was suddenly swimming in a pool that drowned me down. Spending so many nights, back to back, trying to improve my methods always resulted in gaining those not so sharp results, despite taking hundreds of shots in order to overcome the noise. Yes, I have been using those first-line Astro and editing software, but I could never achieve the results that I really wanted.

Hot night. 30 second exposure pin point stars at the beginning of the evening, very low ISO (100) with minimal noise. Taken while mounted on the Skymemo S

As an artist I feel that my artworks must go according the quality I have initially directed to. I eventually managed to create Astro artworks that could be good enough, however not great. So I got the Skymemo S, and since then I increasingly experienced a spike of interest in my artworks from people around the world.

My workshop students have been equally left speechless when they were made aware of the advantages of using that device with low ISO and very long shutter speeds. These days I am still teaching Astrophotography in both methods - with and without the Skymemo S. This has always come to the the unavoidable comments regarding the massive difference in picture qualities!

New Zealand finally can move around and this was the first Astrophotography workshop for this winter (2020). My students enjoyed exploring the Milky Way for their very first time, and Skymemo S was a great tool to work with, and explain them the material!!

Personal Notes

Kenko Skymemo S is a robust device. Right from the moment I held it I knew that this will last forever. Almost the entire body is made of hard metal. If you have ever held the flagship DSLRs or Mirrorless cameras in your hand you would probably appreciate the same feel.

This is built like a tank, and to be honest, with the amount of time that this device is supposed to hold your heavy camera and lens - this robustness is a blessing!

The product weighs 1kg, which as opposed to what we, photographers, always look for, in this case the weight is an advantage. We need to understand that the device has a motor inside of it. The motor needs to work with a lot of weight mounted upon it. The weight of the camera and the lens may totally shake the entire complex should the base is not steady and heavy enough to counter balance.

The motor work is extremely quiet. Once you decide which mode you would like to shoot with, then you can simply forget the device is even there! There are different modes for stars, time-lapse, sun, and Moon, of which I am going to write in a different article. One could expect that such a device will need a specialty battery with loads of volts; however, the Skymemo S only requires 4 regular AA batteries. To let you understand in practical measures, the batteries usually power four Astro nights before they show any sign of low energy. That is very impressive indeed! If you are genuinely afraid not to lose the energy in the middle of the session, there is even an option to connect an external power supply. I never used it, though. I simply did not need to.

Here in Auckland, New Zealand it is safe to say that it never snows, despite the very cold nights in the winter. This is also very rarely get so hot in here during the summer nights. The Skymemo S works GREAT in here, as temperature never seems to make any difference to it.

And this is me, prepared for the night, and mounted my gear on the Skymemo S in order to take some new deep space shots.

For the Southern Hemisphere the polar scope that the device comes with does have some difficulties, as opposed to how it works in the Northern Hemisphere. This is due to the fact that in the Southern Hemisphere we do not have the luxury of the Northern Star (“Polaris”) that you guys from the Northern Hemisphere enjoy of. We need to polar align the Skymemo S either with an app on our phone, or using a guide camera that can be connected directly to the device. I saw no real issues to polar align my Skymemo S using the wonder of a free Astrophotography app that I downloaded to my mobile devices. You can do this, too. Problem solved! However, as a side note, perhaps Kenko can take this in to consideration in the next products marketed here to the Southern Hemisphere users in New Zealand, Australia, South America and Africa.

I totally love the fact that the star tracker can track also the Sun and the Moon, in both hemispheres. This lets me not only use it during those starry nights, but also throughout the day hours. Day and night Time-lapses are a simple work where I do not need to be near by my cameras at all times. The Skymemo S connects (using a cable) into the camera shutter release control (basically, tethering my camera). All I need to choose is the angle of view and the starting point where the very first frame will be taken. And that’s just about it. In the photo to the right, I turned the Skymemo S to a horizontal plane and prepared it for a time-lapse.

The device can go up to 90 degrees, enabling me to take time-lapse videos and still shots in ease!

Skymemo S is also good for such a dreamy artwork. Where low ISO and the incredibly amazing tracking of the stars for long minutes is seen as a brilliant scene. This shot could be made only thanks to the tracking function of the Skymemo S, and the heavy clouds mask most of the stars.

Long minutes exposure in a partially cloudy setting. Made a few long shots and worked them out in post edit. Never dreamed to yield such a brilliant result in such horrible weather and light pollution. Close to the centre is planet Jupiter (the brightest) and below, next to it planet Saturn.

A few last words

This is important to mention that I do not hold an academic degree in Astronomy. My degrees are related to totally different scientific subjects. But in order to start using the Skymemo, one does not actually need to be an Astronomer or a telescope specialist...

For those who are fascinated by, and considering to start Astrophotography I wholeheartedly recommend having this robust yet portable device. The possibilities that Skymemo S is opening to the users are quite a lot, and this stretches well beyond only Astrophotography. I reckon that videographers, time-lapse artists, landscape photographer can also benefit immensely from the device.

Kenko created here a wonderful device that is a must in my photographer backpack.

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I am happy to answer anything regarding the device upon my own experience.

Disclaimer: The device is my own device and Kenko does not pay to me for any of my reviews.

© For all photos and content of this article all rights are reserved to Collins Ryàn – L’artiste, 2020

Did this article help you in your journey? Do you have other topics you would like me to cover? Any other questions? I am here to listen and advise. I would love to hear from you on and on my website


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