Sky-Watcher StarTravel AC 80/400 Refractor Optical Tube - Only tube with accessories, without mounting, without tripod

Sky-Watcher StarTravel AC 80/400 Refractor Optical Tube

The Sky-Watcher StarTravel AC 80/400 is a compact achromatic refractor with an 80 mm aperture and a 400 mm focal length (f/5). Its short tube, light weight and universal mounting arrangement make it one of the most versatile instruments in the Sky-Watcher range - equally suited as a travel astronomy telescope, a richfield instrument for sweeping the night sky, a spotting scope for nature observation or a finder scope mounted alongside a larger instrument. The StarTravel 80 is supplied as an optical tube assembly only, without mount, tripod or eyepiece.

Optics and coatings

The 80 mm achromatic objective lens is fully multi-coated (FMC) on all air-to-glass surfaces. FMC treatment minimises light loss at every lens surface and suppresses unwanted internal reflections, producing a bright, clean image with good contrast. The f/5 focal ratio places the StarTravel 80 in the category of fast refractors - at any given eyepiece the field of view is substantially wider than with longer focal length instruments, the image is brighter and locating objects is easier.

As with all short focal ratio achromatic refractors, some degree of chromatic aberration - colour fringing on bright objects - is inherent to the design. It is most noticeable on the Moon and bright stars at higher magnifications. On extended deep-sky targets at low magnification it is practically invisible and does not affect the observing experience.

What can you observe?

The short focal length and wide field of view make the StarTravel 80 ideal for sweeping wide areas of the night sky. Large open clusters - the Pleiades, Hyades, the Double Cluster in Perseus or the clusters of Orion - fit entirely within the field and look spectacular. The summer Milky Way in Sagittarius reveals panoramas filled with stars, clusters and nebulae. The Great Orion Nebula (M42), the Andromeda Galaxy (M31) and the Triangulum Galaxy (M33) are all natural targets for this type of instrument.

The Moon is sharp and well-defined at moderate magnifications, with good overview of large lunar regions. Planetary observation is possible - Jupiter's main cloud belts and the four Galilean moons are visible, Saturn shows its rings clearly - but for serious high-magnification planetary work a longer focal length telescope is more appropriate. The maximum useful magnification for the StarTravel 80 is around 160x.

For daytime use the telescope works well as a spotting scope for birdwatching and nature observation. An erecting prism or right-angle diagonal (sold separately) is required to produce an upright, correctly oriented image for terrestrial viewing.

Focuser and accessories connection

The 1.25-inch rack-and-pinion focuser is fitted with an integrated T2 thread adapter. With the appropriate T-ring for your camera brand (T-rings are not included), the StarTravel 80 becomes a 400 mm f/5 photographic lens suitable for imaging the Moon, star clusters and wide nebula fields. The focuser locks accessories firmly in place without scratching eyepiece barrels.

Eyepieces and a star diagonal are not included and must be purchased separately. A good starting selection covers focal lengths of approximately 20-32 mm for low magnification sweeping and 6-10 mm for closer views of the Moon and brighter planets. A 1.25-inch star diagonal is required for comfortable astronomical observing at the zenith.

Construction and portability

The tube is built from lightweight materials and kept as short as possible - a defining characteristic of the StarTravel series. The optical tube is held in a pair of mounting rings that allow free rotation for optimal balance and eyepiece positioning. The rings carry a short universal bar with a 1/4-inch photographic thread, allowing the tube to be attached directly to a photographic tripod or adapted to dovetail-equipped telescope mounts using a standard dovetail bar.

The complete tube assembly is light enough to fit in a backpack and compact enough to travel as hand luggage. It is a telescope you will actually take with you - on holiday, to a dark sky camping site or simply into the garden for a quick evening session.

Important note on accessories

This telescope is supplied as an optical tube only (OTA). To use it you will additionally need: a mount or tripod, at least one 1.25-inch eyepiece, and a 1.25-inch star diagonal for astronomical use. All compatible accessories are available in our shop.

Technical specifications