RB Focus Gas S2 Review: A Fully Integrated Windows Control Center for Astrophotography

Introduction

The RB Focus Gas S2 is a Windows-based control center designed specifically for astrophotography rigs. It aims to completely automate your imaging setup by combining a mini PC, controllable DC power outputs, and pre-installed software into a single compact unit. For anyone who has considered building a Windows-based imaging rig, this device offers an integrated alternative to assembling separate components.

The unit weighs just 250 g and is significantly smaller and lighter than dedicated astrophotography control centers like the Eagle 6. It comes with a Celeron N5105 processor, which is modest but adequate for running the essential imaging software. The Gas S2 is available in three configurations: 4 GB RAM with 64 GB storage, 8 GB RAM with 128 GB storage, and 16 GB RAM with 256 GB storage.

What Is the RB Focus Gas S2?

At its core, the Gas S2 is a Windows mini PC built specifically for astrophotography. Unlike general-purpose mini PCs that require additional accessories to control your equipment, this device integrates power management directly into the hardware. It features an XT30 DC input that supports up to 12 volts and 10 amps, which powers five fully controllable DC output ports. These ports can be switched on and off from a pre-installed application or through an ASCOM driver, allowing seamless integration with imaging software.

In addition to the five standard DC ports, the Gas S2 includes two dedicated heater output ports. These ports allow you to set the power intensity manually or switch to automatic mode, where the built-in temperature and humidity sensor calculates the dew point and adjusts power output accordingly. This means dew heaters can be managed without constant babysitting during an imaging session.

The device also provides four USB 2 ports and two USB 3 ports, giving you plenty of connectivity for cameras, focusers, mounts, and other accessories. A micro SD card reader is included for additional storage, and a small LCD screen on the front displays the system status, including whether the Wi-Fi hotspot is active.

Design and Build Quality

The Gas S2 is remarkably compact, weighing only 250 g. This makes it easy to mount directly on your telescope using the included 3D printed bracket, which attaches to a standard finder shoe. The small footprint means it does not add significant weight or bulk to your rig, unlike larger control centers that can weigh over a kilogram.

The unit includes a Wi-Fi antenna that delivers an impressively strong hotspot signal. In testing, the hotspot maintained perfect quality even three floors away from the device, which is notably better than many competing solutions. The hotspot works flawlessly even in remote locations without any network reception, making it reliable for field use.

One minor drawback is the bright LCD screen on the front, which can be distracting in the dark. A firmware update is planned to allow turning the screen off, but until then, a piece of electrical tape is a practical workaround. The integrated fan is virtually vibration-free, so it will not introduce any issues with your imaging.

Software and Integration

The Gas S2 comes with a pre-configured Windows installation optimized for performance. Visual effects and animations are disabled to maximize the limited CPU resources. The system includes a substantial amount of pre-installed software, including ASCOM drivers, NINA, PHD2, SharpCap, and Stellarium. This means you can connect and control your equipment within minutes of unboxing, rather than spending hours setting up drivers and configurations.

The RB Focus power panel application provides direct control over all DC output ports. You can monitor voltage, amperage, temperature, and humidity from a single interface. The heater ports can be set to automatic mode, where the system adjusts power based on dew point calculations.

Integration with NINA is particularly strong. Through the pre-installed ASCOM switch driver, you can control all power ports directly within NINA’s interface and even within its advanced sequencer. This allows you to automate the entire imaging process, from cooling the camera and opening the flat panel cover to turning off equipment at the end of the session. For example, you can set a sequence step to power on the camera, wait for it to initialize, and then connect it, all without manual intervention.

Smartphone Control

The Gas S2 can be controlled from a smartphone using the Touch and Stars plugin for NINA, along with the Advanced API and ThreePoint Polar Alignment plugins. Once configured, you can access the full control interface from a mobile browser or the Android app. This includes controlling the mount, camera, flat panel, and even the power ports through the ASCOM switch driver.

This smartphone integration makes the Gas S2 a more compelling alternative to dedicated control centers like the ASI Air. While the initial setup requires installing the plugins and enabling the appropriate settings, the result is a polished mobile experience that works well in the field. The ability to control power ports from your phone adds a level of convenience that is rare in Windows-based setups.

Performance in the Field

The Celeron N5105 processor is not the most powerful option available, but it handles the demands of astrophotography software without issue. It performed well with an IMX571 sensor camera, and the system remained responsive throughout imaging sessions. The processor is actually more capable than the J-series CPU found in the Eagle 6, which is a notable point in the Gas S2’s favor.

The device was tested under challenging conditions in a light-polluted city, producing a three-hour dataset of the M51 galaxy with a QHY MiniCam 8. The results demonstrate that the Gas S2 is capable of supporting serious imaging work, even in less-than-ideal skies.

One consideration is that the base model with 4 GB of RAM is not recommended. Modern astrophotography software and operating systems benefit significantly from more memory, and 4 GB is simply not enough for future-proofing. The 8 GB configuration is the sensible starting point, with the 16 GB version available for those who want maximum headroom.

Buying Advice

The RB Focus Gas S2 is priced at €430 for the base model, €565 for the 8 GB/128 GB version, and €665 for the 16 GB/256 GB version. While the base model is tempting on price, the 8 GB configuration is the one to choose for a system that will remain usable for years to come.

Compared to the Eagle 6, which starts at around €1,000, the Gas S2 offers a significantly lower price point while providing similar integrated functionality. The Eagle 6 does offer more power ports and USB connectivity, which may be necessary for very complex rigs, but for the majority of setups, the Gas S2 provides everything you need.

It is worth noting that you could build a comparable system using a general-purpose mini PC and a separate power box, potentially at a slightly lower cost. However, the Gas S2’s advantage lies in its integration. Everything is pre-installed, the hotspot is configured, and the power ports are controllable through ASCOM, which means less time setting up and more time imaging.

Conclusion

The RB Focus Gas S2 is a well-executed control center that brings together the flexibility of Windows-based astrophotography with the convenience of integrated power management. Its compact size, reliable hotspot, and seamless NINA integration make it a compelling choice for anyone looking to automate their imaging rig.

While the price is higher than building your own solution from separate components, the integration and out-of-the-box experience justify the cost for most users. If you have been considering an Eagle 6, the Gas S2 deserves serious consideration as a lighter, more affordable alternative that delivers comparable functionality.