Image – PekDar – Astrophotography Engineering

SynScan GOTO controller – trouble with buttons

PekDar — Sun, 13 Jul 2025 08:28:25 +0000

Even though this article has been around for ages, it still offers valuable insights and practical support for users of the SkyWatcher NEQ6Pro mounts. The content has been refreshed and tailored to match the current website engine, making sure everything looks and runs as smoothly as possible.

At some point while using the controller, I noticed that the ESC button wasn’t always working. I lived with it, but after a while, the left Ra button also started acting up and wouldn’t always connect. A red flag went up in my head – something needed to be done. It’s worth noting that the problems appeared right after the warranty period ended… coincidence?

There weren’t many options, just two: either send the controller for service and pay a considerable amount for the repair, or try to fix it myself. My tinkering nature took over (as always), and I set about solving the problem on my own.

I assumed that some dirt or substance must have gotten inside, which over time became sticky and was gripping the button. I don’t recall spilling any liquid on the controller, but I also can’t rule out a situation where rain or high humidity (fog) penetrated the controller’s interior.

My recent, not-so-great experiences with electronics, especially those manufactured in China, gave me an idea of what I might find inside, so I prepared a few things for the job.

Contact spray – quite a nice product for cleaning and degreasing electronics and optical devices, including removing contaminants from glass without damaging optical coatings.
Cotton swabs are a must-have.

IPA PLUS – contact

Plastik 70 spray – in my electronics work, I usually reach for Plastik 70 spray (clear lacquer). It creates a thin, transparent, and, most importantly, sealed coating. It excellently protects soldering points from the tin components oxidizing and forming ‘cold solder’ joints, which stop conducting electricity relatively quickly after service work.
A small, so-called artistic brush will be necessary to precisely and evenly spread the Plastik 70 over the repaired surfaces.

PLASTIK 70 – spray plastic

Let’s get to work.

We’re unscrewing the controller; it’s held together by 4 Phillips head screws.

SynScan controller – back screws

There are no clips, so slowly and gently, but without excessive force, we remove the housing. On the left side, carefully disconnect the white ribbon cable (signal) with the white plug and the plug with the colored wires (power).

SynScan controller – PCB – comm tape and power line

Grab the PCB board from the left side and slowly, gently turn it over to the right side.

Contamination is visible at the soldering points of the white ribbon cable. Below, you can see dirty pads for the ESC button. Now I know where the problem with the uneven operation came from; it would connect sometimes and sometimes it wouldn’t – irritating.

SynScan – PCB – dirty solder points and pads

It’s not that visible in the photo, but the direction button pads weren’t exactly clean either. It was quite noticeable under the light.

SynScan – PCB – dirty pads

The opposite end of the controller, was also dirty. The soldering points of the disconnected plugs. The button pads were also dirty. I’m at my wit’s end. There’s no choice, the entire PCB will have to be cleaned.

SynScan – PCB – dirty solder points

How to clean without breaking anything? Spray a little of the substance into the removed cap from the contact cleaner and dip a cotton swab in it. Lightly wipe out the dirty areas. Repeat the process until all the dirt is removed.

Once you’ve cleaned all the areas, you need to protect the soldering points. Plastik 70 and a brush will be used for this purpose. The procedure is very similar to cleaning. Spray a little of the substance into the removed cap. Use the brush to apply the Plastik 70 to the soldering points. Wait 10 minutes for the applied Plastik 70 to dry.”

View of the controller after cleaning the soldering points of the electronics, pads, and applying a protective plastic coating to the soldering points:

SynScan – PCB – solder points nad pads – cleaned and renovated

SynScan – PCB – cleaned pads

I think it turned out quite decently. In my assessment, that’s everything.

All that’s left is to reassemble the controller and test its operation. The problems that occurred earlier have disappeared.

SynScan – renovated and fully functional

Stars over Teide – Tenerife 2019 (night‑sky time‑lapse)

PekDar — Fri, 25 Dec 2020 21:52:56 +0000

Stars over Teide – Tenerife 2019

This short night-sky time-lapse over Teide was created during the PTMA expedition to Tenerife in 2019. Composed of 140 frames, the sequence demonstrates the smooth motion of stars relative to Earth’s rotation over the volcanic landscape of Las Cañadas.

Why Teide Offers an Advantage Teide is Spain’s highest peak (approx. 3715–3718 m a.s.l.) and the heart of Parque Nacional del Teide, a UNESCO World Heritage site since 2007 – one of the most valuable volcanic landscapes in the world.

Observational conditions are shaped by the “Mar de Nubes” – a trade-wind inversion layer. Cool, moist air and clouds below “cut off” coastal light pollution, while above (over 2000 m a.s.l.), the air remains dry and stable. This results in a darker background and superior image stability (seeing).

The sky quality is also legally protected since 1988 by the “Ley del Cielo” (regulating outdoor lighting, radio emissions, and flight paths), which tangibly supports the observatories’ work. Nearby, at Izaña (approx. 2390 m), operates the Teide Observatory – a key European center for solar research and photometry. While the Atacama in Chile holds the global record for atmospheric dryness, Teide remains the reference site for astronomy in Europe.

Shot Parameters (Time-lapse)

Frames: 140 (compiled into 3 sequences; two played faster to visualize dynamics).
Location: Vicinity of the Las Cañadas caldera (Tenerife), approx. 2200 m a.s.l.
Phenomenon: Visible apparent motion of the celestial sphere due to Earth’s rotation.

Visual Analysis The footage is dominated by the concentric arcs of star motion over a raw, volcanic foreground. Near the low horizon, a slight glow from the cloud layer (“sea of clouds”) is visible – acting as a natural “filter” suppressing light pollution from the tourist towns below.

Sources / Further Reading

UNESCO – Teide National Park (WH status since 2007)
IAC – Teide Observatory (location, altitude)
Starlight / “Sky of Teide” (inversion, “sea of clouds”, certification)
Teide – elevation & context

M45 – Pleiades: two captures of one object + complete guide

PekDar — Sun, 06 Dec 2020 12:37:27 +0000

M45 Pleiades (Seven Sisters)

is one of the most iconic DSO targets — a young open cluster dominated by hot B‑type stars embedded in a blue reflection nebula. The distance is about 444–445 light‑years, the total brightness ~1.6 mag, and the apparent size ~2° (~4 Moons). It sits in Taurus, best observed from late autumn to winter.

The cluster is dominated by hot blue and luminous stars that have formed within the last 100 million years. Reflection nebulae around the brightest stars were once thought to be left over material from the formation of the cluster, but are now considered likely to be an unrelated dust cloud in the interstellar medium through which the stars are currently passing.

Object: key facts

RA/Dec (J2000): ~03h 47m, +24° 07′ (Taurus).
Distance: ~444–445 ly (Gaia/HST; literature varies slightly).
Age: ~100 Myr (range 75–150 Myr depending on method).
Size & mag: ~2° across; ~1.6 mag.
Reflection nebulae: NGC 1432 (Maia) and NGC 1435 (Merope); the dust is unrelated to the cluster’s formation — the stars are passing through an interstellar cloud.
Evolution: the cluster will disperse in ~250 Myr due to galactic interactions.

New research (2025): Using TESS + Gaia, astronomers identified a Greater Pleiades Complex — a dispersed family of >3,000 related stars spanning ~1,900 ly, tripling the known membership context. This doesn’t change the visual M45 appearance but reframes cluster dynamics.

Astro Pixel Processor – Basic Tutorial (Step‑by‑Step Guide)

PekDar — Thu, 03 Dec 2020 17:22:56 +0000

The main goal of this Astro Pixel Processor tutorial is to provide you, with the ability to quickly stack photos using the APP program, in the shortest possible time with minimal the baggage of knowledge need. I share with you what I know. I have gained experience using the APP program on my own.

Remember that each photo of collected lights is different and the examples below, will not necessarily work for your collected photo lights. You should always look for the optimal settings and solutions for each lights. Please, note that I am not the Developer of the APP (Astro Pixel Processor), but only I’m user like you. I don’t know answer to every question that bothers you. Nor am I any representative of the APP Developer or its publisher.

APP provides flexible stacking algorithms compared to DSS, supports mosaics, gradient correction, and multi‑session integration. A great balance between simplicity and power.

M8 Lagoon and M20 Trifid Nebulae

PekDar — Thu, 26 Nov 2020 20:15:21 +0000

M8 Lagoon Nebulae is a giant interstellar cloud in the constellation Sagittarius. It is classified as an emission nebula and as an H II region. The Lagoon Nebula is estimated to be between 4,000-6,000 light-years away from the Earth.

StarStaX and Star Trails – Photo Stacking and Gap Filling

PekDar — Fri, 06 Nov 2020 20:36:41 +0000

Why StarStaX?

In modern landscape astrophotography, creating Star Trails by taking hundreds of shorter exposures is preferred over a single, hours-long shot. This approach has a key practical advantage: if a flashlight shines into the lens, a car passes by, or the tripod gets bumped, you simply discard that single frame rather than losing the entire night’s work. To combine these frames into a final image, StarStaX is the go-to free software. It is lightweight, fast, and dedicated specifically to this task.

How It Works?

The “Lighten” Mode StarStaX does not sum up light in the traditional way (which would result in an overexposed, white image). It uses the “Lighten” blending mode. The software analyzes every pixel across all images and selects only the one with the highest brightness value for the final output.

This ensures bright stars “overwrite” the dark sky background.
Noise in the shadows does not accumulate, keeping the final image clean.

The Gap Problem and “Gap Filling”

There is always a tiny delay between shots (time for the camera to write the file to the card). As a result, after stacking, star trails might look like dashed lines (“beads on a string”). StarStaX solves this with the Gap Filling feature. The algorithm analyzes the end of a star trail on one frame and the beginning on the next, mathematically interpolating the missing segment. The result is perfectly smooth arcs, even if your camera has a slower buffer.

“Comet Mode” Option

An interesting addition is the Comet Mode. The software simulates a gradual fading of the star trail, adding dynamics and a sense of motion to the image, resembling a meteor shower or comets.

Creating Star Trails is one of the most spectacular astrophotography techniques. In this comprehensive step-by-step tutorial, you will learn how to stack a series of individual frames into one stunning image using the free StarStax software. This guide includes the essential step of RAW file conversion to a lossless 16-bit PNG format using RawTherapee, and it’s friendly for Linux users (as it uses free, multi-platform tools).

Capturing Star Trails in a photo is not to difficult task. There are several schools to do this. The Internet has many descriptions and videos on how to do this. I think I’ll never become a YouTuber, personally I prefer to create a document or simple instruction that describe the whole ho-to process in clear technical language and this was what it guide me during preparation this description.

Star Trails over Teide – Tenerife

PekDar — Sun, 01 Nov 2020 16:56:12 +0000

In overall, this was my third or fourth attempt to capture Star Trails. In the end, I was able to make a slightly longer photo shoot, which shows long, bright and clear trails. In the lower left corner of the screen, long white streaks of light are the lights of Italian tourists – amateurs of the night sky like we do. I remember how loud and chatty they were. The word “Polonia” was fell several times as they looked in our direction. I guess how they knew when my company, a modest number of three people, emptied the turbo-cola with raising toast.

Just above the companions from Italy, a small cluster of white light at the left edge of the frame, are also tourists who were probably descending Teide at night.

Near the bottom of the frame, center to right, white streaks of light are the lights of cars on the road nearby.

Star Trails over Teide – Tenerife

I had some luck and throughout the frame, I caught a few meteors.

M33 (Triangulum Galaxy) and NGC 604 – Surface Brightness Analysis

PekDar — Wed, 14 Oct 2020 18:58:51 +0000

M33 Triangulum Galaxy

The Third Player M33, known as the Triangulum Galaxy, is the third-largest member of our Local Group (after M31 and the Milky Way), located approximately 2.8 million light-years away. Although catalogs list it as a bright object (+5.7 mag), for an astrophotographer, it is a classic trap. M33 is positioned almost perfectly “face-on” relative to Earth. Its light is spread over a massive area of the sky (approx. 70 x 40 arcminutes – more than two Full Moons!).

Engineering Conclusion: This results in extremely low surface brightness (approx. 23 mag/arcsec²). This means the signal from the spiral arms is only marginally stronger than the background noise (Sky Glow). Capturing the disk’s periphery requires perfect calibration (Flat frames) and dark skies.

Object Anatomy

SA(s)cd Galaxy Unlike Andromeda (M31), M33 is classified as SA(s)cd. What does this code mean?

No Bar (SA): A pure spiral.
Loosely Wound Arms (cd): The arms are not tightly wrapped, allowing for easy separation of individual star clouds.
No Central Bulge: This is a key feature. M33 likely lacks a supermassive black hole at its center (or it is very small), making it a unique subject for studying the evolution of “pure” galactic disks.

NGC 604

The Monster in the Arm Looking at the image, in one of the spiral arms (usually in the upper-left section, depending on orientation), a distinct red patch is visible. This is not a sensor artifact. This is NGC 604.

Scale: It is a gigantic H II region with a diameter of nearly 1500 light-years.
Comparison: If NGC 604 were located where our Orion Nebula (M42) is, it would be so bright that it would cast shadows on Earth at night.
Physics: It is a nursery where over 200 massive O and B-type stars ignited in a single astronomical moment (approx. 3 million years ago). Their stellar wind is so powerful that it blows “bubbles” in the galaxy’s structure, visible in H-alpha band images.

Technical Imaging Aspect

To highlight the structure of NGC 604 and other smaller H II regions scattered across the arms (red “knots”), it is highly recommended to blend H-alpha narrowband signal into the RGB data. This acts as a contrast booster for ionized hydrogen, allowing these regions to cut through the blue glare of young star clusters.

Two different locations, more than 200 km apart. Two different telescopes, different size, focal length,
light. Two different tools for collecting photons with completely different parameters.

Until now, my computer didn’t really have much to count, but everything changed when I get idea to try, to stack two totally
different data sets together. I like such challenges. I’ve spent a lot of time on it with processing stack. The average of time consumed with one single stack processing, took me around 6 hours. It was test stacks + experiments…. I’ve lost in time how many there were, hours or maybe days spent only for the processing of the data itself. Anyway, the power meter count what it wanted and I will pay for this later.

An interesting fact for me was, that the result stack reached a resolution of 23k x 23k [px], and its size was of 6.3 GB. Displaying such an image greedy consumed ¾ from the available memory of my computer. Processing such a photo was a bit tiring, after cropping it was better, but the final .png file with photo, was just over 300MB in the resolution of 9085 x 6950 [px].

Well…. I must admit that I had a lot of fun with it and a lot of side text was written during processing of stack. Something will come of it.

Source:
https://en.wikipedia.org/wiki/Triangulum_Galaxy

Location
1: I’ve collected light frames with few different sessions. Photos taken on 2019 at Zwardoń and Bieszczady during PTMA rally.

Composition: Astro Pixel Processor,

Processing: GIMP + plug-ins (Linux).

Location 2: Photos collected at 9.2020 near Bielsko-Biała.

Stack processing: APP
Photo processing: Raw Therapee +
GIMP + plugins (Linux)
Lights: 340 x 40[s]
Darks, Bias, Flats, DarkFlats

M42 (Orion Nebula): From Dark Dust to the Blinding Trapezium

PekDar — Sat, 12 Sep 2020 22:02:41 +0000

M42 Orion Nebula

The Nearest Nursery M42, the Great Orion Nebula, is the undisputed queen of the winter sky. Located just 1344 light-years away, it is the closest region of massive star formation to Earth. Due to its proximity and brightness (visible to the naked eye), it allows for a detailed analysis of matter creation and destruction processes that remain invisible to us in other galaxies.

This article presents two different approaches to the same object, revealing its complex nature: the surrounding dark dust and the energetic heart.

The Dust Cloak (Outer Structures)

Looking at the deeper parts of the image, we see that M42 is not suspended in a void. It is part of the gigantic Orion Molecular Cloud (OMC-1).

Dark Nebulae: The gray, “dirty” structures surrounding the bright center are dense interstellar dust. This is the building material that has not yet been ionized by the stars.
Context: Here, we witness the dynamic battle between light and matter. Radiation from the center “pushes” and sculpts these clouds, creating shockwaves within the medium.

The Nebula Engine and H-alpha

The second image and next reveals completely different physics – ionization and the core.

Red Color: The dominant red is the signature of hydrogen (H-alpha line). It indicates high energy in this region.
The Trapezium Cluster (Theta-1 Orionis): At the very center, often overexposed in amateur images, lies a cluster of young, massive stars – the Trapezium. These four main stars (A, B, C, D) are the “engine” of the entire nebula. Their powerful UV radiation illuminates the gas over hundreds of light-years and has excavated the visible “cavity” in the center of the cloud seen in the image.

Technical Challenge

Dynamic Range (HDR) M42 is one of the most difficult objects to expose correctly due to its extreme dynamic range. The brightness difference between the core (Trapezium) and the outer dust loops is so vast that a camera sensor cannot capture both in a single exposure. To show the nebula’s center (rather than a blown-out white patch) alongside faint outer veils, it is necessary to use HDR (High Dynamic Range) techniques or layer masking, blending short exposures (for the core) with long ones (for the background).

Source: https://en.wikipedia.org/wiki/Orion_Nebula

First photo taken on October 2019.

Composition: APP (13 frames)
Processing: RawTherapee and GIMP v2.10.18 + add-ons (Linux)
Lights: 13 x 600[s], ISO-400;
Bias, Flats

Second and next photos:

Composition: Astro Pixel Processor v1.078,
Processing: GIMP v2.10.14 + plug-ins and RawTherapee 5.6,
Lights: 21 x 60[s] ISO 1600,
Flats: 20, ISO-1600,
Darks: 9, ISO-1600,
Bias: 20, ISO-1600

Aurora Borealis: Solar Wind Physics over Iceland

PekDar — Sat, 29 Aug 2020 18:27:17 +0000

Aurora Borealis: The Magnetic Proving Ground

The Northern Lights are not just a visual spectacle, but primarily a visualization of Earth’s magnetic field protecting us from space. The images presented in this article were captured during expeditions to Iceland (including the Hellissandur region), which, due to its location at 64-66° North latitude, sits directly beneath the “auroral oval.”

The Mechanism: Energy Generator What we perceive as dancing lights is the result of collisions.

Solar Wind: The Sun ejects a stream of charged particles (protons and electrons).
Magnetosphere: Earth’s magnetic field intercepts these particles and funnels them toward the poles.
Excitation: When these particles strike the upper atmosphere, they transfer energy to atoms. As these atoms return to their ground state, they emit a photon—light.

Aurora Borealis – Island

Sky Spectroscopy

Why Different Colors? In my photographs, you can observe not only the dominant green but also purples and reds. The color depends on two factors: the type of gas and the altitude of the collision.

Green ( $557.7 \text{ nm}$ ): The most common sight. Produced by collisions with oxygen atoms at altitudes of approx. 100-150 km. The human eye is most sensitive to this band.
Red ( $630.0 \text{ nm}$ ): Rarer, visible during strong geomagnetic storms. This is also oxygen, but at very high altitudes (>200 km).
Purple/Blue ( $427.8 \text{ nm}$ ): Produced by the ionization of nitrogen molecules ( $N_2$ ). It is typically seen in the lower parts of the auroral “curtain,” below 100 km, where the atmosphere is denser.

Photographic Aspect

Freezing the Structure Photographing the aurora is a balancing act between exposure and motion. The aurora is dynamic.

Shutter Speed: Too long (over 15-20s) will blur the structure of the “pillars,” turning them into a shapeless blob. To capture the curtain details visible in these images, I used exposure times in the range of 5-10 seconds at high ISO.
Bz Index: For the aurora hunter, the Bz parameter (interplanetary magnetic field orientation) is more critical than the Kp index. Only a negative (South) Bz value guarantees a spectacular show.

Miejscowość: Hellissandur

Gallery: Lights of the North

Below is a complete collection of photographs documenting the various forms and colors of the Aurora Borealis captured over the Icelandic landscape.

More about phenoma: https://en.wikipedia.org/wiki/Aurora

Photo tech.:

ISO 1600
Light: 10 [s] – 15 [s]
Processing: RawTherapee and Gimp

Aurora in Motion: The Magnetic Dance (Time-Lapse Video)

While static photography reveals the detail and structure of the “pillars,” only time-lapse videography captures the true nature of the phenomenon—its unpredictable dynamics. The video below was created using the time-lapse technique. The camera took a photo every few seconds, which were then stitched together into a seamless movie.

What to watch: Note the “rippling” of the curtain’s lower edge and the sudden outbursts (substorms) that can alter the brightness of the entire sky in just minutes. This serves as visual proof of how volatile the solar wind stream striking Earth’s magnetosphere really is.

Aurora Borealis video with sound. Play loud!