Hubble UL18 – A Lightweight 18" Dobsonian Telescope

The Hubble UL18 is a made-to-order 18-inch Dobsonian telescope, built specifically for serious visual observers who want true observatory-class performance in a portable, transportable design.

With a massive 18-inch primary mirror, the UL18 gathers over five times more light than an 8-inch telescope, and more than twice the light grasp of a 12-inch, unlocking faint galaxies, delicate nebular structure, and extreme planetary detail that simply isn’t possible with smaller apertures.

Light, Strong, and Surprisingly Portable

Each UL18 is custom built to order using precision-machined all-metal components. The truss construction uses eight rigid aluminium truss tubes and a folding altitude bearing structure to provide exceptional stiffness while keeping overall weight under control.

The large mirror box design protects the primary mirror during transport, while the modular layout allows the telescope to be broken down quickly for storage or travel. Fully assembled, the UL18 weighs just ~33 kg, making it one of the most portable 18-inch class Dobsonians available.

Optical Performance

At the heart of the UL18 is a premium parabolic primary mirror, individually tested and finished to achieve diffraction-limited performance (Strehl 0.95+). The secondary mirror is specified to 1/10 wave or better, ensuring excellent contrast and pinpoint stellar images across the field.

Both mirrors receive 96% enhanced reflective coatings, maximising light throughput while reducing scatter. This results in brighter deep-sky views, improved low-contrast detail, and excellent planetary performance even at extreme magnifications.

Choose Your Telescope Control

The UL18 can be customised to suit your observing style. You can use it fully manually, or opt for Guided Push-To or Automatic Go-To systems.

Manual Mode
Even without electronics, the UL18 is a precision Dobsonian with smooth, stable bearings and an easy-to-use truss design. You can enjoy the classic hands-on experience, exploring the night sky exactly as the great visual observers have for decades.

Guided Push-To Version
The UL18 Guided Push-To version features the SkyHub2 digital setting circle system, providing accurate real-time telescope positioning without motorised tracking. High-resolution 8192 PPR encoders on both axes continuously update your telescope’s position in compatible planetarium software.

• Alignment is fast and intuitive using a simple one-star alignment, with optional two-star alignment for increased accuracy.

• Works with SkySafari, Stellarium, Cartes du Ciel, TheSky, and other ASCOM-compatible software on Windows, macOS, Android, and iOS devices.

• Extremely low power consumption: up to 100 hours from a 15,000 mAh USB power bank.

• WiFi and Bluetooth supported (WiFi only for iOS devices).

Automatic Go-To Version
The UL18 Go-To version adds fully motorised pointing and tracking for a completely hands-free observing experience. It includes a smart hand controller with a 30,000-object database and supports advanced 1–9 star alignment for precise pointing accuracy.

• Built-in encoders and a real-time clock maintain accurate sidereal, lunar, and solar tracking rates.

• Control via WiFi or Bluetooth using SkySafari, Stellarium, or ASCOM/INDI-compatible software on Windows, macOS, Linux, iOS, or Android.

• Adjustable slew and guide speeds, spiral search, and park/unpark functionality provide smooth, precise movement for extended observing sessions.

Choosing Your Focal Ratio: f/4.0 or f/4.5

The UL18 is available in f/4.0 or f/4.5, allowing you to prioritise either maximum comfort or maximum optical refinement.

Why choose f/4.0?

• Lower eyepiece height – no ladder required for most users

• More compact overall system

• Wider true field of view

• Ideal for observers who value comfort and portability

Why choose f/4.5?

• Reduced coma across the field

• Slightly smaller secondary obstruction

• Better suited to high-power planetary and lunar observing

• Preferred by observers seeking ultimate optical purity

Both versions deliver extraordinary performance. The f/4.0 favours ergonomic comfort and wide-field observing, while the f/4.5 favours optical cleanliness and contrast. The choice ultimately comes down to observing style and personal preference.

Specifications (UL18)

Hubble UL20 – A Lightweight 20" Dobsonian Telescope

The Hubble UL20 is a made-to-order 20-inch Dobsonian telescope designed for observers who want truly extreme aperture without the bulk and weight of traditional large Dobsonians.

With its enormous 20-inch primary mirror, the UL20 gathers over six times more light than an 8-inch telescope, and almost three times the light grasp of a 12-inch, revealing galaxies, nebulae, and fine structure at a level normally reserved for permanent observatory installations.

A Premium, Light, Compact and Portable Design

Despite its size, the UL20 is engineered to remain practical and transportable. The precision-machined all-metal truss construction delivers exceptional rigidity while keeping overall weight to around half that of traditional 20-inch Dobsonians.

The modular truss design allows the telescope to be broken down for transport, while the reinforced mirror box protects the primary mirror during storage and travel. This makes the UL20 a genuine “portable observatory” for dedicated deep-sky observers.

Optical Performance

At the heart of the UL20 is a premium parabolic primary mirror, individually tested and finished to achieve diffraction-limited performance (Strehl 0.95+). The secondary mirror is specified to 1/10 wave or better, ensuring excellent contrast and pinpoint stellar images across the field.

Both mirrors receive 96% enhanced reflective coatings, maximising light throughput while reducing scatter. This results in breathtaking deep-sky views, extremely faint object detection, and exceptional planetary performance even at very high magnifications.

Choose Your Telescope Control

The UL20 can be customised to suit your observing style. You can use it fully manually, or opt for Guided Push-To or Automatic Go-To systems.

Manual Mode
Even without electronics, the UL20 remains a precision Dobsonian with smooth, stable bearings and a well-balanced truss structure. This allows for classic hands-on observing with direct control and intuitive sky navigation.

Guided Push-To Version
The UL20 Guided Push-To version features the SkyHub2 digital setting circle system, providing accurate real-time telescope positioning without motorised tracking. High-resolution 8192 PPR encoders on both axes continuously update your telescope’s position in compatible planetarium software.

• Fast one-star alignment, with optional two-star alignment for higher accuracy

• Compatible with SkySafari, Stellarium, Cartes du Ciel, TheSky, and other ASCOM software

• Works on Windows, macOS, Android, and iOS devices

• Extremely low power consumption, up to 100 hours from a 15,000 mAh USB power bank

• WiFi and Bluetooth supported (WiFi only for iOS devices)

Automatic Go-To Version
The UL20 Go-To version adds fully motorised pointing and tracking for a hands-free observing experience. It includes a smart hand controller with a 30,000-object database and supports advanced 1–9 star alignment for high pointing accuracy.

• Built-in encoders and real-time clock maintain accurate sidereal, lunar, and solar tracking rates

• Control via WiFi or Bluetooth using SkySafari, Stellarium, or ASCOM/INDI software

• Compatible with Windows, macOS, Linux, iOS, and Android

• Adjustable slew and guide speeds, spiral search, and park/unpark functionality

Choosing Your Focal Ratio: f/3.3, f/3.7 or f/4.2

The UL20 is available in three focal ratios, allowing you to balance comfort, optical performance, and field of view.

Why choose f/4.2?

• Sharper images with almost 50% less coma than f/3.7

• Smaller central obstruction (3.5" secondary vs 4.0" on f/3.7)

• Easier to achieve perfect collimation

• Better suited for high-magnification lunar and planetary observing

• A coma corrector is helpful but not essential for many users

Why choose f/3.3 or f/3.7?

• No ladder required at all for f/3.3; only a small step may be needed for f/4.2 near zenith

• Extremely wide true field of view, especially with f/3.3

• Ideal for sweeping large nebulae and rich Milky Way fields

All three versions deliver extraordinary performance. A coma corrector is strongly recommended for the UL20 f/3.3, while the f/4.2 prioritises optical cleanliness and ease of use.

Thanks to Hubble’s two-section truss design for f/4.2 (single-section for f/3.3 and f/3.7), all versions remain equally rigid and transportable. Please note that counterweights may be required for balance, depending on configuration, and are not included.

Specifications (UL20)

Hubble UL24 – A Lightweight 24" Dobsonian Telescope

The Hubble UL24 is a made-to-order 24-inch Dobsonian telescope, designed for experienced observers who want truly extreme aperture without sacrificing transportability.

With a huge 24-inch primary mirror, the UL24 delivers around nine times the light grasp of an 8-inch telescope and four times that of a 12-inch, revealing ultra-faint galaxies, subtle nebular structure, and fine detail in planetary nebulae that smaller instruments simply cannot reach.

Light, Strong, and Surprisingly Portable

The UL24 features a precision-machined all-metal construction with eight rigid aluminium truss tubes and an extremely strong folding altitude bearing structure. Despite its massive aperture, the complete telescope weighs only around 70 kg, making it dramatically lighter than traditional 24-inch Dobsonians.

A real mirror box protects the primary mirror during transport, while the modular design allows the telescope to be broken down into manageable components for storage and travel. The heaviest single component is the primary mirror at around 30 kg, allowing one person to realistically transport the system to dark-sky locations.

Optical Performance

At the heart of the UL24 is a premium parabolic primary mirror with a full 24-inch optical surface and an overall diameter of 24.4 inches. This provides around 4% more true optical area than many other 24-inch designs that use undersized optical surfaces.

Each mirror is individually tested and finished to achieve diffraction-limited performance, with a Strehl ratio of 0.95+ for the primary and 1/10 wave or better for the secondary. Both mirrors receive 96% enhanced reflective coatings, maximising light throughput and contrast while reducing scatter.

The fast f/3.3 focal ratio keeps the eyepiece height to just 1955 mm at zenith, allowing most observers to use the telescope without a ladder while still enjoying extreme aperture.

Choose Your Telescope Control

The UL24 can be customised to suit your observing style. You can use it fully manually, or opt for Guided Push-To or Automatic Go-To systems.

Manual Mode

Even without electronics, the UL24 remains a highly refined Dobsonian with smooth, stable motion and precise balance. Manual observing delivers the classic deep-sky experience at a scale few observers ever reach.

Guided Push-To Version

The Guided Push-To version uses the SkyHub2 digital setting circle system, providing accurate real-time positioning without motorised tracking. High-resolution encoders on both axes feed live position data into compatible planetarium software.

Alignment is quick and intuitive using one- or two-star alignment. The system works with SkySafari, Stellarium, Cartes du Ciel, TheSky, and other ASCOM-compatible software on Windows, macOS, Android, and iOS devices.

Power consumption is extremely low, allowing up to 100 hours of operation from a standard USB power bank. Both WiFi and Bluetooth are supported.

Automatic Go-To Version

The Go-To version adds fully motorised pointing and tracking for hands-free observing. A smart hand controller with a 30,000-object database supports multi-star alignment for highly accurate pointing.

Built-in encoders and a real-time clock maintain accurate sidereal, lunar, and solar tracking. The system can be controlled via WiFi or Bluetooth using SkySafari, Stellarium, or ASCOM/INDI-compatible software on Windows, macOS, Linux, iOS, or Android.

Adjustable slew and guide speeds, spiral search, and park/unpark functionality ensure smooth, precise operation during long observing sessions.