Why and When a Computer-Based Control is Needed in Field

 

When using a star tracker, you only need to do a polar alignment and setup a multi-exposure sequence to start shooting. This can be done either directly in the camera, with an intervalometer or in the app of the star tacker, like the app for the Sky-Watcher Star Adventurer Mini. In theory, the same would also work with an EQ or an AZ mount and a real telescope as long as the exposures and the focal length are short. 200mm and exposures of 2min and longer will require guiding in most cases. Guiding corrects tracking errors of a star tracker or a mount. In our times, “guiding” is actually “auto-guiding”. In the “dark”, past times, guiding used to be manual – manual guiding. Guiding generally requires an additional camera and often an additional mini-telescope. Guiding corrections have to be coordinated with the tracking which is performed by the mount. Things become complicated. Like in may other cases, humans use a computer for complex things. Why guiding is mentioned as first on this page. It seems to be a kind of trigger of a ripple effect where you need more and more gear to use and take with you.

Even though there are very powerful dedicated auto-guiding devices, like MGEN III, a large number of people still use a portable computer in the field. A dedicated autoguiding device might cost as much as a small notebook. Many people have it anyways. The PHD2 guiding tool is almost a standard today and runs on all desktop platforms.

In addition to guiding, there are other things where a computer seems to be needed in the field:

• A tool to control your camera, potentially coordinated with guiding, for example for dithering
• A tool to navigate in the sky
• A stack of drivers to control the mount
• A tool which can help you to focus the lens or the telescope
• A tool which switches the filters if you use a dedicated mono-camera

This makes you busy and pulls more things you need:

• Large battery
• A table
• A chair
• Something to keep the dew or icing away from the notebook
• Other things you need when you use a computer…

Reason Why not Using a Notebook

 

You might be enjoying these possibilities of the 21st century and, as a nerd, the vast amount of gadgets around you. As a photographer you probably already learned that simple and less things work better and fail less often. As a beginner it is also very essential to reduce the clutter, amount of stuff you can forget, and the software to update…

A notebook requires power, much more power and a different power than your camera and your mount. All this requires a table or a place to put all that stuff on. There is dew in the night in most places in the world. Notebooks do not like moisture.

And at the end, most importantly, you are here to make pictures and not for an office work. This is my view. I guess, quite some beginners might feel the same.

There is still a considerable part of astrophotography community which has a stationary installation in their backyards and enjoys the process from a desktop PC in a cozy place inside the house, and then later in dreams while sleeping 🙂 Some of you might not have a backyard at all. My backyard has a limited view on Polaris and large parts of the sky are obscured by trees and other houses. Not speaking of light pollution even though I’m just in the Bortle 5 area. I usually go to a few dark spots in one hour drive (Bortle 3) and sometimes to a less darker (Bortle 4), but a closer location. I have no time and no interest to take more things with me than really mandatory.

The Non-Notebook Compact Choices

The advance of mini-computers, especially Raspberry Pi, in last years brought up quite some good choices. Today, I would even predict that in five years a notebook will be used for astrophotography mostly in stationary setups.

Ekos and KStars on a Raspberry Pi

In the recent years, the Ekos platform and the whole KStars open source project progressed a lot. When using it, it becomes cleat that the largest user group are small private observatories and other stationary installations. You can remotely put a cover on your scope and close the dome the observatory if clouds are coming. For this, you definitely need desktop style computer.

With the power of mini-computers, like Raspberry Pi 4 (8GB RAM are strongly recommended), Ekos and KStars are often used in portable setups. [Astroberry]{https://www.astroberry.io/} is pre-made Raspberry Pi distribution with Ekos, KStars some other tools. You still need to configure and install quite a few things on your own.

In contrast, Stellarmate is a real out-of-the-box, plug-n-play Raspberry Pi based hardware and software based on KStars and Ekos with everything pre-installed and pre-configured. There is a mobile app which is getting better and better. Stellarmate provides very good tutorials on their channel on YouTube. These tutorials are a must-see for any beginner! I initially used Stellarmate OS on my Raspberry Pi before switching to ZWO ASIAIR. Some day, I will use it again.

If you are interested to dive deeper in details of installation and configuration, you can follow some DIY guides for Raspberry Pi, like the one from Gregory Giuliani: Raspberry Pi 4 configuration for Astronomy.

Lacerta MGEN-3

Lacerta MGEN-3 is an auto-guider solution with additional features, like camera control and polar alignment. Today, it is in the 3rd generation and is known for its high-precision auto-guiding. With MGEN-3, you still need a computerized Go-To solution. You can use one which provided with the mount, but I was so disappointed by SynScan from StarWatcher that I started to look for something less complicated and better integrated.

StarAid

The StarAid is a relatively “new kind on the block”. It looks like Lacerta MGEN-3 in a more compact form and with integrated optics. Like with Lacerta MGEN-3, you still need a solution for Go-To. The maker refers to the mount software for Go-To operations. StarAid supports plate solving, but it is not clear if and how a Go-To can be verified by this plate solving.

Systems for Everyone – No Knowledge Requited… only sufficient Funds

Progressing computing technologies allow doing far more today. A few companies work and offer on all-in-one device which should make accessible for everyone and almost everywhere:

• https://unistellaroptics.com
• https://vaonis.com/stellina
• https://vaonis.com/stellina-vs-vespera
• https://www.kickstarter.com/projects/1324372410/hiuni-a-smart-connected-goto-telescope/

Their comfort some with its price… It is most probably the simplest way to get an own Deep Sky picture. The quality seems be rather average.

The Atik Infinity camera stands out a bit, since it approaches the desired simplicity from another angle. It uses a special video camera to automatically acquire and stack image frames into a ready-to-go picture. You still need a lens or a telescope, a mount, and a guiding setup to use it.

ZWO ASIAIR and ASIAIR Pro

ZWO ASIAIR stand outs from all the solutions listed above. Its approach is to integrate the entire functionality in one system. This aproache similar to Stellarmate. Stellarmate still requires a computer keyboard and a two-button mouse even though a control via VNC is possible. Stellarmate also requires a monitor even though a mobile app is available for generic session control.

ASIAIR is a true all-in-one, out-of-the-box, point-n-shoot solution. There is a growing community of ASIAIR fans and I’m the one of them. Your only control device is your smartphone which is connected to ASIAIR directly via WiFi. The control app is simple to use and does not expose most advanced details which are not needed in most cases anyways. ASIAIR keeps running if the smartphone gets out of the WiFi range or you stop the app. The low range of WiFi is probably the only weak point. AIRAIR is based on Raspberry Pi 4 which has some hardware design flows affecting WiFi antenna performance. Plus, the folks from ZWO decided to put it in an aluminum case which limits the range even further. You still will have a good coverage in 5-7m away. More requires an WiFi extender.

There are some good video overviews about ASIAIR:

• By Peter Zelinka : https://www.youtube.com/watch?v=C43xWCLm1fw
• By Trevor Jones at AstroBackyard: https://www.youtube.com/watch?v=TwDoKpvajoo

There are still a few things you need to pay attention to when getting  one and using it:

• ASIAIR does not support all DSLR and mirrorless cameras. You should review the list of supported cameras on the product page. A future version of the firmware is said to support more cameras, bit this did not happen yet at the time of writing (March 2021).
• AIRAIR supports only ZWO cameras for guiding. The main camera should be either a DSLR and mirrorless cameras as mentioned above or a ZWO camera
• Many mounts are supported by ASIAIR. They can be connected in different ways. Depending on the mount and the type of connection, you still might need to run through additional setup steps using the hand controller of the mount including time and coordinate settings, star alignment, etc. In my opinion, this degrades the value and advantages of ASIAIR a lot. I use a direct cable connection from ASIAIR to the mount. It is known as “EQdir cable”. It was once developed in the EQMod project for Sky-Watcher mounts. In this case, a hand controller is not needed at all. The mount does not need more than just power. iOptron and Losmandy mounts are known to work in a similar simple way.