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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.

PrimaLuceLab ESATTO 3" Robotic microFocuser

by PrimaLuceLab
SKU PLL-PLLEST3
$945.00 - $945.00
$945.00
$945.00 - $945.00
$945.00
Price Match Policy!
  • 76.3mm Clear Aperture
  • 8 kg Payload Capacity
  • 25mm Draw Tube Travel
  • 0.04 Micron per Step Resolution
  • ASCOM, WiFi, and USB-C Control
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • PrimaLuceLab ESATTO 3" Robotic microFocuser

    The PrimaLuceLab ESATTO 3" Robotic microFocuser combines a massive 76.3mm clear aperture with an 8 kg payload capacity, designed for large refractors and cassegrains with heavy imaging trains. Its 25mm of draw tube travel is controlled with a resolution of 0.04 microns per step, ensuring absolute precision for achieving critical focus. A low profile of just 58mm and a weight of 1345 grams keeps the entire assembly compact and manageable on your telescope.

    Crayford Design: 8 kg Payload Capacity with Zero Flexure

    Engineered for heavy instrumentation, the ESATTO 3" utilizes a Crayford-style mechanism supported by 28 ball bearings. This design provides the rigidity needed to carry an 8 kg imaging train—including large format cameras, filter wheels, and off-axis guiders—without introducing sag or flexure. With a minimal thickness of only 58mm, it adds very little length to your optical path, preserving back focus for complex accessory configurations.

    Robotic Precision: 25mm of Travel at 0.04 Micron Resolution

    The core of the ESATTO 3" is its high-resolution stepper motor, which moves the drawtube in increments as small as 0.04 microns. This level of precision is critical for automated focusing routines on fast optical systems, like Ritchey-Chrétiens or refractors with reducers, where the critical focus zone is exceptionally narrow. The 25mm of total travel gives you ample range to accommodate different cameras and accessories without needing to reconfigure your setup.

    All-in-One Control: WiFi, USB-C, and ASCOM Compatibility

    The ESATTO 3" eliminates the need for external motor controllers by integrating all electronics into its housing. You can connect and power it via a modern USB-C port from an EAGLE or any Windows computer, with a full ASCOM driver for compatibility with software like N.I.N.A. or SGP. For computer-free operation, built-in WiFi lets you control the focuser from a smartphone or tablet using the Virtual HandPad app, perfect for both visual observing and remote setup.

    Ecosystem Ready: ARCO Port and M81x1 Camera Connection

    Designed for seamless integration, the ESATTO 3" features a dedicated ARCO port that provides both power and data to the optional ARCO robotic rotator. This single-cable connection dramatically simplifies wire management at the telescope. The drawtube terminates in a secure M81x1 male thread, allowing you to attach your camera via optional stop-ring adapters for a rigid, perfectly orthogonal connection that is superior to standard 2" compression fittings.

    ESATTO 3" vs. ESATTO 2": The 76.3mm Aperture Advantage

    The primary distinction between the ESATTO 3" and its 2" sibling is the clear aperture. The 3" model provides a 76.3mm light path, a significant increase over the 51mm aperture of the 2" version. This makes the ESATTO 3" essential for preventing vignetting when using large-format sensors (APS-C and full-frame) or when installing focal reducers and correctors inside the optical train. For large refractors, RCs, or Cassegrains, the 3" aperture is required to fully illuminate the field.

  • What is the main advantage of the ESATTO 3" over the 2" model?

    The primary advantage is the 76.3mm clear aperture, compared to 51mm on the 2" model. This is critical for illuminating large camera sensors and avoiding vignetting with focal reducers on telescopes like large Ritchey-Chrétiens or apochromatic refractors.

    Can I control the ESATTO 3" focuser without a computer at the telescope?

    Yes. The ESATTO 3" has built-in WiFi, allowing you to connect directly from a smartphone or tablet using the Virtual HandPad app for precise remote focusing. This is ideal for visual use or for making adjustments without a dedicated PC.

    How does the ESATTO 3" connect to my camera to prevent flexure?

    It uses a secure M81x1 male thread on the drawtube. Optional adapters with stop rings are available to create a rigid, threaded connection to your specific camera, eliminating the sag and tilt common with standard 2" compression-ring visual backs.

    What is the benefit of the ARCO port on the ESATTO 3"?

    The ARCO port provides both power and data to the optional ARCO robotic rotator through a single, short cable. This means you only need one power/data line running to the focuser, which then powers the rotator, greatly simplifying cable management at the back of your telescope.

    I have a 12" f/8 Ritchey-Chrétien with a full-frame camera and filter wheel. Is the ESATTO 3" strong enough?

    Absolutely. The ESATTO 3" is designed for this exact scenario. Its 8 kg payload capacity and 28-bearing Crayford design can handle heavy imaging trains without flexure, and the 76.3mm aperture ensures your full-frame sensor is fully illuminated without vignetting.

    Will the ESATTO 3" work with my existing ASCOM-compatible software like N.I.N.A. or SGP?

    Yes. The ESATTO 3" includes a dedicated ASCOM driver, allowing it to be controlled directly from any standard astrophotography software that supports the ASCOM platform. It will integrate seamlessly into your existing automated imaging workflow.

  • Focuser Type Robotic Crayford
    Clear Aperture 76.3 mm
    Draw Tube Travel 25 mm
    Payload Capacity 8 kg
    Resolution per Step 0.04 microns
    Minimum Thickness 58 mm
    Bearings 28 ball bearings
    Weight 1345 g
    Camera Side Connection M81x1 Male Thread
    PC Connection USB-C
    Wireless Connection WiFi
    Expansion Port ARCO Port for Robotic Rotator
    Software Control PLAY, ASCOM Driver, Virtual HandPad App

    • ESATTO 3" Robotic microFocuser

      × 1

    • USB-C to USB-A Cable

      × 1

  • PrimaLuceLab 1-Year Warranty