Sky-Watcher EvoStar 80 APO Doublet Refractor

Introduction

The Sky-Watcher EvoStar 80 APO Doublet Refractor is engineered for astronomers seeking exceptional optical performance for both visual observation and astrophotography. This manual provides detailed instructions for the proper setup, operation, and maintenance of your telescope, ensuring a rewarding experience under the night sky.

Featuring a matched doublet objective lens with a synthetic fluorite element and proprietary Metallic High-Transmission Coatings (MHTC™), the EvoStar 80 APO minimizes chromatic aberration and delivers tack-sharp, high-contrast images. Its versatile design makes it suitable for both novice and experienced users.

What's in the Box

Upon unpacking, please verify that all components listed below are present and in good condition:

• Optical Tube Assembly (OTA)
• Two 1.25-inch Eyepieces (LET 25mm and LET 5mm)
• 2-inch Dual-Speed Crayford-Style Focuser (integrated)
• Tube Rings (set of 2)
• V-Style Dovetail Bar
• 8x50 Right-Angle Correct Image (RACI) Finderscope with Bracket
• 2-inch Dielectric Diagonal
• 1.25-inch Focuser Adapter
• Foam-Lined Aluminum Hard Case

Image: The Sky-Watcher EvoStar 80 APO Doublet Refractor with included accessories.

Setup and Assembly

1. Mounting the Optical Tube

   Carefully remove the optical tube from its case. Attach the tube rings to your compatible equatorial or alt-azimuth mount's dovetail saddle. Ensure the V-style dovetail bar on the telescope is securely seated in the mount's saddle and tightened. Proper balance is crucial for stable viewing.

   

   Image: The EvoStar 80 APO optical tube mounted on a telescope tripod.

2. Attaching the Finderscope

   Slide the 8x50 Right-Angle Correct Image (RACI) Finderscope into its bracket on the optical tube. Secure it with the thumbscrew. The finderscope is essential for locating celestial objects before observing them through the main telescope.

   

   Image: Detail of the finderscope attachment point.

3. Installing the Diagonal and Eyepiece

   Insert the 2-inch Dielectric Diagonal into the focuser drawtube and secure it with the thumbscrew. For 1.25-inch eyepieces, insert the 1.25-inch focuser adapter into the diagonal first, then insert your chosen eyepiece (e.g., 25mm or 5mm LET) into the adapter and secure it. For 2-inch eyepieces, insert directly into the diagonal.

   

   Image: The focuser assembly with diagonal and eyepiece ready for use.

4. Focuser Operation

   The 2-inch dual-speed Crayford-style focuser allows for precise focusing. Use the larger knob for coarse adjustments and the smaller knob for fine-tuning, which provides a 10:1 reduction ratio. This fine adjustment is particularly useful for achieving critical focus during high-magnification visual observations or astrophotography.

   

   Image: Detailed view of the dual-speed focuser mechanism.

Operating Your Telescope

Aligning the Finderscope

Before observing, align your finderscope with the main telescope. Point the main telescope at a distant, stationary object (e.g., a street light or a distant tree during the day). Center the object in the main telescope's eyepiece. Then, adjust the finderscope's alignment screws until the same object is centered in its crosshairs. This ensures that whatever you see in the finderscope is also visible in the main telescope.

Observing Techniques

• Visual Astronomy: Start with the lowest magnification eyepiece (e.g., 25mm) for a wider field of view, making it easier to locate objects. Once the object is centered, you can switch to higher magnification eyepieces (e.g., 5mm) for more detailed views.
• Astrophotography: The EvoStar 80 APO is well-suited for astrophotography due to its excellent color correction. You will need an appropriate camera adapter (T-ring and T-adapter) to connect your DSLR or dedicated astronomy camera to the focuser. Precise focusing using the dual-speed focuser is critical for sharp astrophotographs.

Image: The Sky-Watcher EvoStar 80 APO ready for observation.

Maintenance and Care

• Optics Cleaning: Dust on the objective lens or eyepieces should be removed with a soft brush or compressed air. For smudges or fingerprints, use a specialized optical cleaning solution and a microfiber cloth. Avoid touching optical surfaces directly.
• Storage: Always store your telescope in its foam-lined aluminum case when not in use to protect it from dust, moisture, and accidental damage. Store in a dry, temperature-stable environment.
• Dew Prevention: In humid conditions, dew can form on the objective lens. A dew shield (integrated) helps, but for prolonged observation, a heated dew strap may be necessary.

Image: The objective lens of the EvoStar 80 APO, showing its multi-coatings.

Troubleshooting

Specifications

Warranty and Support

Sky-Watcher products are backed by a limited warranty against defects in materials and workmanship. For specific warranty terms and conditions, please refer to the warranty card included with your product or visit the official Sky-Watcher website. Keep your proof of purchase for warranty claims.

For technical support, troubleshooting assistance, or spare parts, please contact Sky-Watcher customer service. Contact information can typically be found on the manufacturer's website or in the product packaging.

Note: Proposition 65 Warning applies to this product.