Sky-Watcher Zoom 7-21mm 1.25 inch Eyepiece

Many telescope owners struggle to find the right eyepiece for different celestial targets, often needing to swap between multiple fixed focal lengths. The Sky-Watcher Zoom 7-21mm 1.25" eyepiece solves this by offering a continuous range of magnifications in one unit, eliminating the need to carry and change eyepieces in the dark.

Who is it for

This eyepiece is ideal for amateur astronomers who want versatility without the hassle of multiple eyepieces. It suits both beginners looking for an easy way to explore different magnifications and experienced observers who appreciate the convenience of a zoom during public outreach or quick observing sessions.

Main features

• Zoom focal length from 7mm to 21mm for variable magnification
• Standard 1.25" barrel fits most telescope focusers
• Fully multi-coated optics for bright, high-contrast views
• Foldable rubber eyecup for comfortable viewing with or without glasses
• Smooth zoom mechanism allows precise adjustment while observing

Specifications

• Eyepiece Type: Zoom
• Focal Length Range: 7mm - 21mm
• Barrel Size: 1.25" (31.7mm)
• Apparent Field of View: 30° at 21mm, 43° at 7mm
• Eye Relief: 15mm - 18mm
• Optical Design: 8 elements in 5 groups
• Lens Coating: Fully Multi-Coated
• Filter Thread Size: 1.25"
• Eyecup Type: Foldable Rubber
• Housing Material: Anodized Aluminum
• Blackened Lens Edges: Yes
• Zoom Mechanism: Smooth, continuous rotation
• Compatibility: All telescopes with 1.25" focusers
• Optical System: Achromatic
• Internal Baffling: Yes

Tips

When using the zoom eyepiece, start at the 21mm setting to locate and center your target, then gradually zoom in to higher magnification. Keep in mind that atmospheric conditions often limit useful magnification, so the 7mm setting may be best reserved for nights of steady seeing.