The Orion StarBlast 4.5 Astro Reflector is a compact 114mm (4.5-inch) Newtonian reflector on a tabletop Dobsonian mount. Its unusually short 450mm focal length gives it a focal ratio of f/3.9, producing relatively wide views of the night sky from a telescope small enough to move and store easily.
The StarBlast 4.5 is entirely manual. There are no motors, computerized object locating or tracking systems; the telescope is simply moved by hand in altitude and azimuth. Its combination of a short optical tube and simple tabletop mount makes straightforward visual observing the central idea behind the design.
The 114mm aperture provides enough light-gathering ability for useful views of the Moon and planets as well as many brighter deep-sky objects, while the short focal length particularly suits open star clusters, Milky Way star fields and other relatively large targets.
114mm f/3.9 Reflector Optics
The StarBlast 4.5 uses a 114mm parabolic primary mirror with a 450mm focal length, producing a fast focal ratio of f/3.9. Its Newtonian design uses a secondary mirror to direct the incoming light to an eyepiece mounted near the front of the optical tube.
The short focal length is one of the telescope’s defining characteristics. With an appropriate low-power eyepiece, it can provide wide views of the night sky, making it particularly well suited to large open clusters and rich star fields.
Higher magnifications can still be used for the Moon and planets by changing eyepieces, although the telescope’s fast optical system places greater demands on accurate collimation and eyepiece performance than a slower reflector.
Tabletop Dobsonian Mount
The StarBlast 4.5 uses a compact tabletop Dobsonian-style altitude-azimuth mount. The telescope moves up and down in altitude and from side to side in azimuth, allowing it to be pointed manually anywhere across the sky.
There is no conventional tripod. Instead, the complete telescope is placed on a solid, stable support at a comfortable observing height. A sturdy table, bench or other suitable platform can work well, while an unstable surface can introduce vibration and make focusing more difficult.
The tabletop arrangement keeps the complete telescope considerably more compact than a conventional floor-standing Dobsonian. The base also incorporates a carrying handle, making the telescope relatively straightforward to move as a complete unit.
What Can You See Through the StarBlast 4.5?
The Moon is an easy target for the StarBlast 4.5, with craters, mountain ranges, maria and shadows along the terminator visible under suitable conditions.
The bright planets are also accessible. Jupiter’s four Galilean moons and principal cloud belts can be observed, while Saturn’s rings can be clearly distinguished from the planet. Venus shows its phases, and Mars can reveal some surface detail when it is favorably positioned and atmospheric conditions are good.
The telescope’s short focal length makes larger open clusters and star fields particularly natural targets. Objects such as the Pleiades and Beehive Cluster suit its relatively wide-field character, while its 114mm aperture can also reveal brighter nebulae, globular clusters and galaxies under sufficiently dark skies.
Faint deep-sky objects remain dependent on observing conditions and light pollution, and they will generally appear much subtler through the eyepiece than in long-exposure astronomical photographs.
Simple Manual Operation
The StarBlast 4.5 is a completely manual telescope. Objects are located using the finder and then the optical tube is pushed by hand until the target appears in the eyepiece.
As Earth rotates, objects gradually drift across the field of view. The observer simply moves the telescope periodically in altitude and azimuth to keep the target visible. There is no computerized alignment procedure, electrical power requirement or motorized tracking system.
This simplicity reduces setup compared with a computerized telescope, although it also means that the observer must learn to locate objects independently using recognizable stars, star patterns or charts.
Limitations to Consider
The StarBlast 4.5’s 114mm aperture provides useful observing capability in a compact telescope, but it cannot gather as much light as larger 150mm, 200mm or greater reflectors. Fainter galaxies and nebulae consequently become more challenging, particularly under light-polluted skies.
Its very fast f/3.9 optical system also has trade-offs. Accurate collimation becomes important for obtaining the best image quality, while stars toward the edge of a wide field can show coma, a characteristic optical aberration of fast Newtonian reflectors.
The tabletop mount requires a stable external support at a suitable height, and the telescope provides no motorized object locating or tracking. These characteristics are fundamental parts of its simple, compact design rather than missing accessories.
Its strongest role is therefore as a compact, manually operated wide-field reflector, rather than a telescope designed around computerized operation, high-magnification tracking or long-exposure astrophotography.
For #7 Orion StarBlast 4.5 Astro Reflector, add this after Limitations to Consider and before Specifications:
Who Is the Orion StarBlast 4.5 Best For?
The StarBlast 4.5 is best suited to observers who want a compact, manually operated reflector for wide-field views of star clusters, Milky Way star fields and brighter deep-sky objects, while still being able to observe the Moon and planets. Its tabletop mount and fast f/3.9 optics favor simple, portable visual observing rather than computerized tracking or long-exposure astrophotography.
Specifications
- Optical Design: Newtonian reflector
- Aperture: 114mm (4.5 inches)
- Focal Length: 450mm
- Focal Ratio: f/3.9
- Primary Mirror: Parabolic
- Primary Mirror Coating: Aluminum with SiO2 overcoat
- Secondary Mirror: 34mm minor axis
- Mount: Manual tabletop altitude-azimuth
- Focuser: 1.25-inch rack-and-pinion
- Finder: EZ Finder II