Astronomy Specialist




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Click here for instructions on how to install the ESATTO to refractor telescopes.

ESATTO 3.5" LP is the new low profile robotic focuser specifically designed for the most demanding astrophotography applications. With a thickness of just 32mm, the Esatto 3.5" LP is the perfect match for telescopes with limited backfocus such as fast astrographs.

Features a large 90mm of free aperture, 10mm of focuser travel, 10kg payload capacity and an incredible resolution of 0.01 microns per step. It can be controlled via USB C on any Windows computer or via Wi-Fi using a smartphone or tablet and communicates directly to the ARCO camera rotator. 


 ESATTO 3.5” LP low profile robotic microfocuser - main features:

  • Special low profile design for high load capacity (up to 10 kgs) and precision.
  • Low profile design with an optical thickness of only 32mm.
  • 10mm focuser travel with an incredible resolution of 0.01 microns per step!
  • Special adapters to easily connect it to many different telescopes.
  • It can be directly controlled by EAGLE or any Windows computer with dedicated control software or ASCOM drivers.
  • USB-C connector offering greater reliability and can be connected to any USB type port with the included cable.
  • Wi-Fi capability from any smartphone, tablet or computer and ESATTO Virtual HandPad app for visual use.
  • Many camera threaded adapters with stop ring on the camera side to rotate the camera to the desired angle
  • ARCO port to easily connect the ARCO camera rotator without the need for additional data or 12V power cables.
  • Weight: 1150 g.

Designed to offer the best performance for astrophotography

The special design allows the ESATTO 3.5” LP to have an impressive 10kg payload capacity with the focusing smoothness that is required by modern astrophotography techniques (eg. autofocusing with V-curve).


Includes PLAY, the Prima Luce AstrophotographY Software

ESATTO 3,5” LP comes with PLAY, the all-in-one and easy to use astrophotography software that allows you control your focuser and easy remote operation. ESATTO comes with a sturdy USB-C port (which you can connect to any USB type port thanks to the cable included in the box) to connect to EAGLE or any Windows computer (tested with Windows 10 computers).

PLAY allows you to configure your telescope by selecting OTA and mount type and by connecting to any camera, autoguider, mount, or filter wheel that is has an ASCOM driver (tested with ASCOM platform 6.4 and later). And if you install PLAY on an EAGLE computer, it automatically adds more advanced features!

Note: In order to use PLAY you have to have either the ESATTO focuser or SESTO SENSO 2 focusing motor. PLAY natively supports the new ARCO rotator and ECCO environmental module.


Many adapters available to connect to telescopes and cameras

ESATTO 3,5” LP draw tube travel moves on the telescope side and different optional pre-made adapters are already available to connect to different telescopes. If you don't see what you need, you can contact us for custom adapter manufacturing.

On the camera side, ESATTO 3,5” LP has a M98x1 female thread and, through a complete series of optional camera adapters with stop ring, it allows you to directly connect cameras or to the ARCO rotator. The stop ring allows you to lock the camera at a precise angle to better frame the object.


Connection with a single cable to ARCO camera rotator and field de-rotator

ESATTO includes a special port for ARCO, the robotic camera rotator.  With ARCO you can remotely control the rotation angle of your camera to achieve perfect framing of the object. If you have an alt-az mount, you can use ARCO to de-rotate the field without the need of an equatorial wedge. By connecting ESATTO 3,5” LP to ARCO 3” you will have a rotating focuser with just 58.5mm of thickness and 76.3mm of free aperture.




10 kg

Clear aperture

90 mm


0.01 micron / step

Draw tube excursion

10 mm

Thread on camera side

M98 x 1 female


1150 gr


178 mm x 208.9 mm x 32 mm 





  • Prima Luce Lab Esatto 3.5" LP
  • Power supply cable
  • USB-C cable



ZWO camera software Manual (English) (coming soon)

ZWO camera software Manual (Italian) (coming soon)

ZWO camera software Drivers


To have access to the latest version of the manual, software package and firmware visit 


To connect Esatto via WiFi to your computer, smartphone or tablet and use the virtual hand pad: 

  • Connect your device to the focuser WiFi network ESATTOxxxxx;
  • Enter the password "primalucelab", 
  • Open your browser and enter the address
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