PrimaLuceLab SESTO SENSO 3 LS – Robotic Focusing Motor for Telephoto Lenses

PrimaLuceLab SESTO SENSO 3 LS – Robotic Focusing Motor for Telephoto Lenses

Description

Developed and manufactured in Italy, the PrimaLuceLab SESTO SENSO 3 LS is a premium robotic focusing motor dedicated to telephoto photographic lenses. Building on SESTO SENSO 3 technology, it introduces the new Lens Gear Clamp (LGC), a gear-driven interface that directly engages the lens focus ring for precise, belt-free motion. The integrated encoder maintains accurate position tracking even during manual adjustments, with an Automatic Position Recovery option.
Its high-resolution motor offers 2 million steps for ultra-precise focusing, perfect for astrophotography. USB-C and built-in Wi-Fi enable control from a computer, smartphone, or tablet via the Virtual HandPad. Fully compatible with ARCO rotators, PLAY software, ASCOM drivers, and supporting GHOST mode (USB-free with EAGLE) and DARK mode (dimmable or switchable LEDs), it ensures accurate and convenient operation.
The Arca-Swiss style mount allows easy attachment to a PLUS Vixen-style dovetail bar for use with any Vixen clamp mount. Weighing only 515 g, SESTO SENSO 3 LS delivers exceptional precision and seamless integration into astrophotography setups.

Technical Specifications

• Compact all-in-one design, weight 515 g (1.1 lb)

• Lens Gear Clamp (LGC) with backlash-free gear drive, no external belt required

• Integrated encoder with automatic position recovery

• High-resolution motor with 2 million steps

• USB-C connectivity for PC or EAGLE control

• Built-in Wi-Fi and Virtual HandPad for wireless control

• Compatible with PLAY software and ASCOM drivers

• ARCO rotator port for power and data with a single cable

• DARK mode with adjustable or fully off LEDs

• GHOST mode for USB-free operation with EAGLE

• Temperature sensor port for automatic focus compensation

• Compatible with Canon, Nikon and other photo lenses with manual focus ring

• Two rubber gears included (6 mm and 18 mm) for different focus ring widths

• Arca-Swiss mount for PLUS Vixen dovetail bar

Built upon the success of the first and second generation motors, the SESTO SENSO 3 LS adds exclusive features specifically designed for imaging with photographic lenses, incorporated into a single enclosure to house all the elements that comprise a motorized focusing system for astrophotography.

SESTO SENSO 3 LS robotic focusing motor for telephoto lenses - main features:

• NEW Compact all-in-one chassis designed to be used with telephoto photographic lenses (Canon, Nikon, and others)
• NEW Integrated encoder for position tracking and manual movement without losing motor position, with Automatic Position Recovery option
• NEW Lens Gear Clamp (LGC) with backlash-free, gear-driven coupling for precise motorized focusing of photographic lenses without external belts
• High resolution motor with 2 million steps for precise control manual focuser of telephoto lenses
• USB-C connectivity to control from computers with astronomy software
• WiFi connectivity to control it from smartphone or tablet with the included Virtual HandPad, without the need of computer or physical hand pad
• Compatible with PLAY software to control focus position, also with autofocus
• Provided with ASCOM drivers to let you control through third party astronomy software
• ARCO rotator port to directly connect the ARCO without the need for additional data or power cables
• DARK mode with dimmable LED lights, that can even be turned off completely
• GHOST mode to remove USB cable when used with EAGLE computer
• Temperature sensor port to automatically compensate focus caused by environmental temperature change
• Developed and manufactured in Italy
• Weight: 515 grams (1.1 lbs)

Compact, lightweight and all-in-one design

SESTO SENSO 3 LS features a compact and lightweight enclosure that integrates all control electronics, with all ports conveniently located on the side. The unit includes dimmable status LEDs, which can also be turned off completely to avoid stray light during nighttime imaging sessions with photographic lenses. Connectivity is streamlined and efficient: a USB-C port allows connection to an EAGLE or any Windows® computer using the included USB cable; the dedicated ARCO port enables both power and control of an optional ARCO camera rotator through a single cable; the 12V power port (5.5/2.5mm, center-positive) supplies power to both the motor and internal electronics using the included cigarette lighter-style cable (or with an optional cable for direct connection to the EAGLE); and a temperature sensor port lets you connect the optional probe for use with third-party software that supports automatic focus compensation based on ambient temperature changes.

Easy installation with Lens Gear Clamp (LGC)

SESTO SENSO 3 LS features the new Lens Gear Clamp (LGC), specifically designed for telephoto photographic lenses such as Canon, Nikon, and other models with manual focus rings. This innovative gear-based design eliminates mechanical backlash and ensures smooth, precise motorized focusing without the need for external belts. The integrated rubber gear directly engages the lens focus ring, while the Arca-Swiss style mount allows you to secure SESTO SENSO 3 LS to a PLUS Vixen-style dovetail bar for perfect alignment. Manual focusing is still possible at any time by rotating the lens’s focus ring, while the integrated encoder keeps track of the motor’s position—even after manual adjustments. This makes SESTO SENSO 3 LS ideal for astrophotographers who want the precision of a robotic focusing motor combined with the freedom of manual control.

If your telephoto lens does not include an L-bracket with photo thread for mounting to the PLUS Vixen-style dovetail bar, we offer an optional Secondary Support for Photo Lenses—a dedicated accessory that ensures proper stability and alignment when using SESTO SENSO 3 LS.

To provide optimal grip on different lens focus rings, SESTO SENSO 3 LS comes with two interchangeable rubber gears: one for lenses with focus rings up to 18mm in width, and one for lenses with focus rings thicker than 18mm. This ensures maximum contact and precision across a wide range of compatible lenses. SESTO SENSO 3 LS is compatible with many photographic lenses, such as (but not limited to):

Nikkor Z 70-200mm f/2.8 Vr S
Nikkor Z 100-400mm f/4.5-5.6 VR S Nikkor Z 24-120mm f/4 S Nikkor Z 24-70mm f/4 S
And other telephoto lenses with manual focus ring

Integrated encoder: precise control with freedom of movement

SESTO SENSO 3 LS integrates a high-resolution position encoder that tracks the movement of the motor shaft with extreme accuracy. This allows the user to manually rotate the focus ring of the photographic lens, with SESTO SENSO 3 LS installed and powered on, without losing the motor’s reference position. Ideal for astrophotographers who need to fine-tune focus manually before switching to fully automated control, this feature also improves the initial calibration process.
Another advantage of the integrated encoder is its ability to detect and compensate for small shifts in focus caused by lens mechanics. With this Automatic Position Recovery function, SESTO SENSO 3 LS can also automatically move the lens focus ring back to the previous position if it is rotated manually or accidentally shifted. You can define a recovery delay (from 0 seconds for instant reaction up to 20 seconds). Please note that the encoder detects motor shaft movements only and cannot account for internal mechanical slips in the lens focusing mechanism.

SESTO SENSO 3 LS: dimensions and weight

SESTO SENSO 3 LS includes all these advanced features in a lightweight, compact all-in-one chassis specifically designed to be installed on telephoto lenses without the need for external brackets or adapters. SESTO SENSO 3 LS weighs just 515 grams (1.1 lbs). In the picture you can see the dimensions.