Daystar 80mm f/6 Achromatic Refractor

The 80mm f/6 Achromat: A 480mm Window for Wide-Field Astronomy

With its 480mm focal length, this refractor delivers expansive views that can frame large celestial objects in their entirety. The combination of an 80mm aperture and an f/6 focal ratio creates bright, rich-field images, ideal for sweeping the star clouds of the Milky Way or observing large open clusters like the Pleiades (M45) and the Beehive (M44). This makes it well suited to use as a wide-field telescope on a lightweight alt-azimuth mount.

As an achromatic refractor, the design prioritizes a wide field and portability. This involves a trade-off: some chromatic aberration, or false color, will be visible on very bright targets like the lunar limb, Jupiter, or brilliant stars like Vega. At low to medium powers, this effect is minimal, allowing the telescope to excel at its primary purpose of delivering immersive, wide-angle views.

Optical Design: A Fully Multi-Coated 2-Element System

At the heart of the Daystar 80mm refractor is a 2-element (doublet) objective lens system designed to minimize color aberration. It does not give the colour correction of an apochromat. The optics are fully multi-coated, ensuring high light transmission for brighter images and reduced internal reflections for a darker sky background.

• Achromatic Doublet: The 2-element lens corrects for the most prominent chromatic aberration, bringing the red and blue wavelengths to a closer focus than a simple single lens could.
• Fully Multi-Coated: All air-to-glass surfaces feature multiple layers of anti-reflection coatings to maximize the amount of light reaching your eye or camera sensor.
• 80mm Aperture: Gathers enough light to resolve details in bright deep-sky objects.

Mechanical Construction: A 2-inch Hybrid Focuser and CNC-Machined Tube

The Daystar 80mm refractor is built for durability and precision. The optical tube and focuser body are finely CNC-machined from aluminum and given a deluxe high-gloss anodized finish.

The 2" focuser is a top end Crayford / rack and pinion hybrid drive, also described as a dual speed Crayford hybrid focuser with rack and pinion assist. It accepts 2" eyepieces. A retractable dew shield (sunshade) helps prevent moisture from forming on the objective lens during long nights and blocks stray light to improve contrast.

Night-Sky Observing with the 480mm Focal Length

This telescope excels as a personal window on the cosmos for wide-field viewing. Its 480mm focal length is perfectly suited for low-power, 2" eyepieces that can deliver vast fields of view, making it easy to navigate from star to star and appreciate the context of objects within their stellar neighborhoods. It's an ideal instrument for exploring large-scale structures that are too expansive for longer focal length telescopes.

With its 80mm aperture, you can explore a wide variety of celestial targets. You can find globular clusters like the Hercules Cluster (M13), see the bright core of the Andromeda Galaxy (M31), and split bright, colorful double stars like Albireo (Beta Cygni). The Moon becomes a stunning landscape of craters, mountains, and seas, especially along the terminator.

Solar Observing: Safe Practices for the 80mm Aperture

This refractor can be transformed into a powerful solar telescope, but only with the use of a proper, professionally made solar filter. This telescope is sold without any solar filters, and pointing it at the Sun without one can cause blindness or damage to equipment. You must install a full-aperture solar filter over the front of the telescope before pointing it anywhere near the Sun.

Daystar emphasizes that telescope owners must use caution at all times. Never point the telescope at the Sun without the solar filter safely installed first. While observing, ensure all parts of the assembly are properly affixed and have not been tampered with or removed. This diligence is critical for your safety and the safety of anyone who looks through your telescope.

H-alpha Solar with a Quark: ERF Needs for an 80mm f/6 System

Daystar pairs this 80mm f/6 refractor with a Quark in its 80mm Day/Night Bundle, and the Quark is designed for F/4 to F/9 refractors. The Quark is a rear-mounted filter that reveals the dynamic solar chromosphere, including prominences, filaments, and active regions. However, concentrating sunlight from an 80mm aperture generates significant heat.

Daystar's Quark manual states, "To prevent damage, we recommend using an Energy Rejection Filter on telescopes of 80mm aperture or more, or when tracking the Sun for long periods." An Energy Rejection Filter (ERF) reduces the thermal load on the Quark assembly. For this telescope, options include:

• UV/IR Cut Filter: A filter that threads onto the front of your diagonal, reflecting unwanted ultraviolet and infrared energy back out of the telescope.
• Full-Aperture ERF: A red or yellow glass filter mounted in front of the telescope. For best performance, use this front-mount ERF, as it prevents almost all heat from entering the telescope.

Imaging Applications: From Guiding to Wide-Field Photography

The Daystar 80mm refractor can also be used for imaging. Its 480mm focal length gives a wide field, and its 2" hybrid focuser accepts 2" accessories.

For direct imaging, the telescope is capable of capturing wide-field photos of the Moon, star clusters, and the brightest nebulae. However, due to its achromatic design, astrophotographers should be prepared to manage some blue bloating on bright stars. Daystar offers an optional 2" dielectric-coated mirror diagonal for visual use; its Day/Night bundle page notes the diagonal is removable for straight-through imaging.

Daystar 480 vs. The 80mm Day/Night Bundle

Daystar offers this same 80mm f/6 optical tube as part of their 80mm Day/Night Bundle. The primary difference is the included accessories. This product is the optical tube assembly (OTA) and a case, while the bundle is a complete H-alpha solar observing package.

• Daystar 80mm f/6 Refractor (This Product): Includes the 80mm OTA with its 2" hybrid focuser and an aluminum carrying case. It is a standalone telescope for night-sky use that is ready to be equipped with your choice of mount, diagonal, eyepieces, and solar filters.
• 80mm Day/Night Bundle: Includes the same 80mm OTA but adds a Daystar Quark (in either Chromosphere or Prominence models) and a 2" dielectric mirror diagonal. It is a night time and solar telescope all in one. For H-alpha with an 80mm aperture, an Energy Rejection Filter is recommended.

Choosing this standalone OTA is ideal if you already own a Quark filter, prefer a different solar filtering method, or intend to use the telescope primarily for night-sky observation.