Sky-Watcher Evoguide 50/242 ED guide scope
Professional guide scope for precision astrophotography
The Sky-Watcher Evoguide 50/242 ED is a premium guide scope with ED objective lens (FLP-53) featuring 50mm aperture and 242mm focal length at f/4.8 ratio. This specialized instrument is designed for use as a pointer and autoguider, providing significantly sharper star images compared to standard achromatic refractors. The extra-low dispersion (ED) glass elements minimize chromatic aberration, ensuring precise guiding performance essential for long-exposure astrophotography.
Key features and construction
The Evoguide comes complete with a holder for standard finder shoe mounting, precision metal adjustment screws, and a standard 1.25″ focuser with safety screws. The non-rotating helical focusing system ensures your camera remains perfectly aligned during focus adjustments. An external T2 thread allows direct attachment of cameras with internal T2 threading, while the 20mm back focus (extendable to approximately 60mm when unscrewed) provides excellent versatility for various imaging setups.
Optical performance
- ED objective lens eliminates color fringing for sharp star images
- Fast f/4.8 ratio for bright, detailed views
- 19.5mm fine focusing range with 1mm per revolution precision
- Fixed dew shield integrated into objective design
Versatile mounting and compatibility
The guide scope features standard dovetail shoe mounting compatible with Vixen, Sky-Watcher, GSO, and other major telescope brands. The robust 800g construction includes mounting rings and finder shoe for immediate installation on most telescope systems.
Technical specifications
Optical specifications
- Objective diameter: 50mm
- Focal length: 242mm
- Focal ratio: f/4.8
- Fine focusing range: 19.5mm
- Focusing precision: 1mm per revolution
Mechanical specifications
- Objective thread (tube side): M55.8mm internal
- Dew shield: Fixed, integrated with objective
- Dew shield diameter: 60mm external
- Tube diameter: 56.1mm external
- Objective sleeve diameter: 56mm internal
- Back focus range: 20-60mm
- Focusing type: Non-rotating helical focuser
- Additional focusing: ~5mm via objective threading
- Output connection: 1.25″ + T2 (M42x0.75)
- Focuser optical length: 39mm
- Overall length: 220-260mm
- Weight: 800g (including rings and finder shoe)
- Shipping dimensions: 35 x 22 x 14 cm
- Shipping weight: 1.5kg
Applications and usage
The Evoguide 50/242 ED excels as an autoguider for astrophotography, providing the precision tracking necessary for long-exposure imaging. Its compact design and quality optics also make it an excellent choice as a portable travel telescope when paired with appropriate eyepieces. The ED optics ensure consistent performance across various atmospheric conditions, making it reliable for both visual observation and imaging applications.
Ideal for
- Autoguiding systems for astrophotography
- Portable travel telescope setup
- Wide-field imaging projects
- Educational astronomy programs
