Prometheus Astro has officially announced the new inFocus Max Electronic Focuser, a system designed for astrophotographers running heavier imaging setups who still want something compact, clean, and easy to integrate into their existing workflow.
At first glance, the inFocus Max looks like it was built with real-world astrophotography frustrations in mind. Heavy imaging trains, cable clutter, inconsistent autofocus behavior, and compatibility headaches are all areas this new focuser aims to address. Instead of chasing unnecessary complexity, Prometheus Astro appears focused on delivering strong torque, fine control, environmental sensing, and broad software compatibility in a straightforward package.
The inFocus Max combines a geared stepper motor with integrated control electronics inside a compact housing capable of handling substantial payloads with repeatable precision. One of the more convenient design choices is the single USB-C connection that carries both power and data, helping reduce cable management issues on moving mounts.
It also includes onboard temperature, humidity, and barometric pressure sensors, giving autofocus software additional environmental data that can be useful for focus compensation and long imaging sessions as conditions shift overnight.
For many astrophotographers, the biggest concern with an electronic focuser is whether it can reliably move a fully loaded imaging train without slipping or struggling under weight. Prometheus Astro addresses this with a geared stepper system featuring a 100:1 reduction ratio designed to provide high torque and stable positioning.
The unit is rated for payloads up to 11kg (24.3 pounds), putting it comfortably within the range needed for larger refractors, Newtonian astrographs, and accessory-heavy rigs using cooled cameras, filter wheels, rotators, and off-axis guiders.
That extra torque matters in practical use. Maintaining focus consistency during meridian flips, filter changes, and large temperature swings can make a major difference during long imaging sessions.
The inFocus Max offers an effective step angle of 0.075 degrees, allowing for very fine focus adjustments. Combined with proper backlash compensation inside imaging software, the system should support highly repeatable autofocus routines that rely on small incremental movements to build accurate focus curves.
For astrophotographers who automate their imaging sessions, repeatability is everything. Once tuned correctly, a setup like this can maintain highly consistent focus behavior night after night.
One detail many users will appreciate is the single-cable USB-C approach. Anyone who has spent time fighting cable snags on an equatorial mount knows how valuable cleaner cable routing can be.
The focuser supports both ASCOM and Alpaca out of the box, making it compatible with a large portion of Windows-based astrophotography software ecosystems. INDI support is also planned, which will expand compatibility for Linux and Raspberry Pi-based imaging systems once released.
As always, users should verify compatibility with their preferred imaging applications and autofocus workflows before purchasing.
The built-in environmental sensors are another welcome addition. Temperature compensation has become increasingly important for automated imaging systems, especially with larger optical tubes that experience measurable focus drift throughout the night.
By integrating temperature, humidity, and pressure monitoring directly into the focuser itself, the inFocus Max gives compatible software more accurate local environmental data to work with. That can help trigger autofocus routines or apply focus offsets automatically as conditions change.
Even for users who primarily focus manually, having environmental data logged alongside imaging sessions can still provide useful insight into focus behavior over time.
Prometheus Astro also made a smart decision by designing the inFocus Max around the widely used ZWO EAF mounting pattern.
For many users, that means existing EAF brackets and mounting hardware may already work without requiring custom adapters or modifications. If your telescope already has an EAF installed, upgrading could potentially be a much simpler process.
Of course, checking screw spacing, drawtube clearance, and focuser compatibility is still important before installation.
The focuser uses 6061 aluminum for the front and rear plates along with the mounting hardware, providing a solid and durable structure where mechanical load matters most.
Internally, the central section uses carbon fiber reinforced PETG to support the electronics while helping reduce overall weight. It’s an interesting mixed-material approach that balances rigidity and practicality without unnecessarily increasing mass on the telescope.
Photo Credit: Chronis Iliakis/Prometheus Astro E.E.
Prometheus Astro says the inFocus Max is expected to launch in June 2026, with preorders already open.
Current preorder pricing is expected to land around $170–$190 USD (€160 including VAT), while estimated retail pricing is expected to rise to approximately $210–$240 USD (€200) after release.
If final performance matches the specifications being presented, the pricing positions the inFocus Max as a potentially attractive option for astrophotographers who need higher torque and broader integration features without stepping into significantly more expensive premium focusing systems.
Motor Type: Geared Stepper Motor
Gear Reduction: 100:1
Maximum Payload: Up to 11kg
Effective Step Angle: 0.075°
Connection: USB-C
Sensor Suite: Temperature, Humidity, Barometric Pressure
Mount Compatibility: ZWO EAF mounting pattern
Construction: Aluminum front/rear plates, PETG-CF central body
Use Case: Astrophotography autofocus systems
The inFocus Max appears aimed squarely at astrophotographers running larger, more demanding imaging rigs who want dependable autofocus performance without adding unnecessary complexity to their setup.
Between the high-torque geared stepper design, integrated environmental sensors, USB-C single-cable connectivity, and compatibility with common mounting hardware and software ecosystems, Prometheus Astro seems to be targeting a very practical balance of performance, convenience, and affordability.
As more field testing, autofocus curve samples, and real-world telescope setups are shared over the coming months, it will be interesting to see how the inFocus Max performs in long-session imaging environments where consistency and reliability matter most.
Address:
1855 S Ingram Mill Rd
STE# 201
Springfield, Mo 65804
Phone: 1-844-277-3386
Fax: 417-429-2935
E-Mail: hello@scopetrader.com