PrimaLuceLab ESATTO 4" Robotic microFocuser

102.2mm Aperture and 10 kg Payload for Large Astrographs

Designed to serve large professional telescopes, the ESATTO 4" eliminates vignetting on astrographs with wide, corrected image circles. Its 102.2mm free aperture ensures the entire light cone reaches your full-frame or larger sensor. A robust payload capacity of 10 kg supports heavy imaging setups, including large format cameras, filter wheels, and off-axis guiders, without flexure.

This rigidity is achieved through a sophisticated design incorporating 40 bearings, which guarantees smooth, precise movement even when the telescope is aimed near the zenith. Despite its strength, the focuser maintains a slim 65mm profile, minimizing the impact on your telescope's back focus requirements.

0.04 Micron Resolution with USB-C and WiFi Control

The ESATTO 4" achieves its 0.04-micron resolution through advanced motor control, allowing you to hit the critical focus zone with absolute precision on even the fastest optical systems. You can connect and control the focuser via the reliable, reversible USB-C port from any Windows computer or a PrimaLuceLab EAGLE controller, using the provided ASCOM driver or PLAY astrophotography software.

For operation without a computer, the ESATTO 4" features built-in WiFi. This allows you to connect directly from any smartphone, tablet, or computer to use the Virtual HandPad app, giving you complete control for visual observation or at-the-telescope adjustments.

ARCO Integration: 1 Port for Power and Data

The ESATTO 4" includes a dedicated ARCO port, streamlining its integration with the PrimaLuceLab ARCO robotic rotator. This port provides both power and data to the rotator through a single cable, eliminating the cable management challenges of separate USB and 12V power lines.

When paired, ESATTO and ARCO create a fully robotic focusing and framing system. From your control computer, you can precisely adjust focus and rotate your camera to perfectly frame deep-sky objects. For observers with alt-azimuth mounts, ARCO also functions as a field de-rotator, enabling long-exposure astrophotography without an equatorial wedge.

A Custom Solution for the Takahashi FSQ-106

The ESATTO 4" is the ideal focusing solution for the Takahashi FSQ-106 astrograph, whose large internal corrector demands a focuser with a correspondingly large aperture. PrimaLuceLab has designed optional adapters that allow the ESATTO 4" to replace the stock focuser seamlessly.

This adapter kit ensures the ESATTO 4" combination has the same optical thickness as the original focuser. It also converts the drawtube's M110x1 thread to the M92x1 female thread found on the original, allowing you to reuse your existing camera adapters and spacers to reach focus without recalculating your imaging train.

ESATTO 4" vs. ESATTO 3" and 2": Matching the Focuser to Your Telescope

As the largest model in the ESATTO family, the 4" version is specifically for large instruments where aperture is paramount. The primary differences lie in physical capacity and intended application.

• ESATTO 4": With its 102.2mm aperture and 10 kg payload, this is the choice for observatory telescopes and large-format astrographs like the FSQ-106, where preventing vignetting is the top priority.
• ESATTO 3" and 2": These smaller models offer the same core robotic technology but in a more compact and lighter package suitable for smaller refractors, Newtonians, and SCTs. They are the better choice when the massive aperture of the 4" model is not required, as their lower weight (the 4" weighs 2050 g) makes balancing the telescope easier.