Daystar Sol 80mm Dedicated Solar Telescope

An Integrated 80mm Hydrogen-Alpha Telescope

The Daystar Sol 80 is an all-in-one solar telescope that has its etalon, blocking filter and telecentric barlow built in, so there is no separate front filter or barlow to fit. From the 80mm objective to the 13mm blocking filter, the optical train is designed as a single unit, which offers safety and ease of use without the need for component matching.

This design is intended for astronomers who want a dedicated, high-performance solar instrument that is ready to use out of its case. Weighing 2.8 kg (6.1 lb) with rings, it is a portable tool for detailed visual observation and imaging of the Sun's dynamic atmosphere.

Observing the Sun's Chromosphere in 6562.8Å Light

By isolating the specific 6562.8Å wavelength of Hydrogen-Alpha light, the Sol 80 reveals the Sun's chromosphere, a turbulent layer of gas just above the visible surface (photosphere). This allows you to witness a constantly changing landscape of magnetic activity that is invisible in white light.

• Prominences and Filaments: See vast arcs of plasma extending from the solar limb, and their dark, ribbon-like counterparts silhouetted against the brighter disk.
• Active Regions and Plages: Observe the bright, magnetically complex areas that often surround sunspots, indicating regions of intense solar activity.
• Spicules and Flares: With good seeing, you can resolve the fine, jet-like spicules that form a "burning prairie" at the Sun's edge and witness the abrupt, brilliant energy release of solar flares.

80mm Doublet with a 4.3x Telecentric Barlow

The heart of the optical system is an 80mm air-spaced achromatic doublet objective. Light from this primary lens passes through an integrated, fully baffled 2-element 4.3x telecentric barlow. The barlow produces a slower focal ratio and a more parallel light beam, controlling the angle of light entering the temperature- and angle-sensitive etalon.

This combination results in an effective focal length of 1400mm and a focal ratio of f/17.5. Because of the included barlow, a large magnification is achieved with normal focal length eyepieces and ample backfocus is available.

A Sub-0.5Å Bandwidth with a 13mm Blocking Filter

This Chromosphere model features a filter bandpass of 0.5Å FWHM or narrower. This extremely narrow window is the key to high-contrast views of surface features like filaments, plages, and active region details. While optimized for the chromosphere, this bandwidth is still wide enough to show prominences clearly against the blackness of space.

The system has a 16mm clear etalon aperture (Daystar manual; Daystar's website gives a 19mm clear exit aperture) and an integrated 13mm blocking filter. The blocking filter is a non-removable, essential safety component that rejects out-of-band wavelengths before light reaches the eyepiece or camera. The entire filter assembly is self-contained and requires no user adjustment beyond the electronic tuning.

PID-Controlled Heating and ±0.5Å Manual Wing Shift

Daystar's etalons are tuned by precisely controlling their temperature. The Sol 80 uses an electronic PID (Proportional-Integral-Derivative) controller to heat the etalon to its target temperature and hold it there. An LED indicator shows the status: yellow while settling (approximately 5-6 minutes), green when on-band and ready to observe, and red for a fault such as low voltage.

A manual tuning knob allows for a ±0.5Å wing shift in 0.1Å increments. This lets you slightly shift the filter's center wavelength off the main H-alpha line. This is used to enhance the visibility of Doppler-shifted features, moving toward or away from you: a feature moving towards you will be brighter in blue (counter-clockwise) wing shift, and one moving away will be reddened (clockwise). After each adjustment allow approximately 5-10 minutes for the filter to settle.

12:1 Dual-Speed Rack & Pinion with Motor Support

The Sol 80 is equipped with a Daystar-manufactured 12:1 dual-speed helical rack and pinion focuser. The mechanism provides smooth, precise focus adjustments, with a locking brake to hold position once focus is achieved. The focuser's ample travel accommodates a wide range of configurations, from a camera body mounted flush to the filter to visual use with a 2" diagonal.

Designed with imagers in mind, the focuser is compatible with most third-party focus motors. It provides standard shaft sizes of 6mm (coarse) and 4mm (fine), along with three female M4 threaded holes for attaching motor brackets, enabling remote-controlled focusing during an imaging session.

Eyepiece Selection for the 1400mm Focal Length

Due to the long f/17.5 focal ratio, eyepiece choice is critical for performance. High-quality Plössl eyepieces in the 25mm to 40mm range are recommended. These designs offer high contrast and minimal internal scattering, which is essential for solar viewing. At long focal ratios a high-powered eyepiece can exceed Dawes' limit, so an eyepiece of 32mm or greater gives the best results; higher powers give a fuzzy disk without the ability to focus well.

In Daystar's eyepiece comparisons, zooms and other fast wide-field designs typically performed very badly on Daystar applications. For best results, use eyepieces with fully multi-coated optics and blackened lens edges to maximize contrast and reveal the most subtle chromospheric details.

Solar Imaging: Cameras, Reducers, and the Included Flat Cap

For imaging, use a monochrome camera, as color sensors only use 1 in 4 pixels for red light, reducing both resolution and sensitivity. Short exposures (e.g., 1/15s to 1/500s) are necessary to "freeze" atmospheric seeing.

• Newton's Rings: To combat interference patterns (Newton's Rings) common in monochromatic imaging, a tilt adapter may be required between the telescope and camera.
• Focal Reducers: The 1400mm focal length produces a large image scale. To fit the full solar disk onto smaller camera sensors, an optional focal reducer can be used.
• Flat Cap: An imaging Flat Cap is included in the box. This is used to take calibration frames (flat fields) to correct for dust motes and illumination variations.

5V, 1.5A USB Power for Thermal Control

The etalon's heating and tuning system requires a continuous power source for operation. The telescope is powered via a standard micro-B USB port and requires a 5V supply capable of delivering at least 1.5A. The manual notes that any user-supplied power source, such as a field battery, should be rated for at least 2 amps at 5 volts.

An AC wall adapter (90-240VAC) is included, with interchangeable plugs for the US, UK, Europe, and Australia, allowing you to power the scope from any standard outlet. Computer USB ports and cell phone chargers do not normally supply the 1.5A this telescope needs.

Daystar's Guidelines for Safe Solar Observation

The Daystar Sol 80 is a fully integrated and safe solar telescope when used as directed. The internal filters are permanent and essential for safety. Never attempt to disassemble the telescope, focuser, or filter housing. Removal of any internal component will void the warranty and could result in unfiltered light which can cause blindness or damage to equipment.

Always exercise caution and ensure all components are securely attached before pointing the telescope at the Sun. Never look up along the telescope towards the Sun, and do not leave the telescope unattended unless remote monitoring systems are in place. Daystar also asks owners to inform guest or novice observers of the special nature of the telescope so as not to imply that telescopic observing of the Sun is safe without proper filtration.

2.8 kg Weight, Integrated Finder, and Vixen Dovetail

Engineered for portability, the Sol 80 weighs just 2.8 kg (6.1 lb) with its mounting rings attached. The clever carry handle also incorporates a simple and effective solar finder: simply adjust the telescope's pointing until the bright dot of sunlight is centered on the finder's rear white screen.

The telescope includes a Vixen-compatible dovetail bar for mounts that accept a Vixen-style dovetail. The dovetail also features a standard 1/4-20 tapped hole, allowing it to be mounted directly onto a sturdy photographic tripod for quick setup and grab-and-go observing sessions.

Daystar Sol 80 vs. a Quark on an 80mm Refractor

A common alternative to a dedicated solar scope is adding a Daystar Quark filter to an existing refractor. The two approaches differ in how the system is put together.

• Quark: Daystar designs the Quark for F/4 to F/9 refractors, and its Quark manual recommends an Energy Rejection Filter on telescopes of 80mm aperture or more, or when tracking the Sun for long periods.
• Sol 80: The objective, 4.3x telecentric barlow, 13mm blocking filter and etalon are built into one telescope, so there is no separate filter or barlow to fit and the solar finder is part of the carry handle.
• Accessories: The Sol is compatible with Daystar's Quark accessories, including the 2" eyepiece adapter, imaging tilt adapters, focal reducers and battery.

The Sol 80 suits observers who want an integrated H-alpha telescope; a Quark suits those who want to use a refractor they already own.