Sky-Watcher S11550 Maksutov-Newtonian 190mm Telescope User Manual

1. Introduction

This manual provides essential instructions for the assembly, operation, and maintenance of your Sky-Watcher S11550 Maksutov-Newtonian 190mm telescope. The Maksutov-Newtonian design offers a unique combination of large aperture and excellent field correction, making it suitable for both visual observation and astrophotography. Please read these instructions carefully before using your telescope to ensure optimal performance and longevity.

Image 1.1: The Sky-Watcher S11550 Maksutov-Newtonian 190mm telescope, showcasing its optical tube assembly with finder scope and mounting rings.

2. What's in the Box

Verify that all components are present upon unpacking:

• Telescope Optical Tube Assembly (OTA)
• 8x50 Right Angle Finderscope
• 2-inch T-Ring Adapter
• V-Style Dovetail Plate and Rings

3. Setup and Assembly

3.1 Mounting the Telescope

1. Attach the V-style dovetail plate to your equatorial mount. Ensure it is securely fastened.
2. Place the telescope optical tube assembly (OTA) into the mounting rings. Tighten the rings evenly to hold the telescope firmly without overtightening.
3. Balance the telescope on the mount by sliding it forward or backward within the rings until it remains stable in any position.

Image 3.1: Side view of the telescope, illustrating the focuser and finderscope attachment points.

3.2 Attaching the Finderscope

1. Locate the finderscope bracket on the telescope tube.
2. Slide the 8x50 right angle finderscope into its bracket. Secure it with the provided thumbscrews.
3. Align the finderscope with the main telescope. This is done by pointing the main telescope at a distant, stationary object (e.g., a distant tree or lamppost) during daylight hours. Look through the main telescope with a low-power eyepiece and center the object. Then, adjust the finderscope's alignment screws until the same object is centered in the finderscope's crosshairs.

Image 3.2: Front view of the telescope, showing the objective lens and the finderscope mounted.

3.3 Installing Eyepieces

1. Loosen the thumbscrews on the focuser drawtube.
2. Insert your desired eyepiece into the focuser.
3. Gently tighten the thumbscrews to secure the eyepiece. Do not overtighten.

4. Operating the Telescope

4.1 Focusing

The Sky-Watcher S11550 features a 2-inch dual-speed 10:1 Crayford focuser. This allows for precise focusing:

• Use the larger knob for coarse adjustments to quickly bring objects into approximate focus.
• Use the smaller knob for fine adjustments to achieve critical focus. This is particularly useful for high-magnification observations and astrophotography.

Image 4.1: Rear view of the telescope, highlighting the dual-speed Crayford focuser.

4.2 Observing

1. Begin with a low-power eyepiece to locate your desired celestial object.
2. Use the aligned finderscope to point the telescope towards the object.
3. Once the object is visible in the main telescope's field of view, use the focuser to achieve a sharp image.
4. For more detailed views, switch to higher-power eyepieces. Refocus after changing eyepieces.

The 190mm aperture and 1000mm focal length (f/5.3) of this Maksutov-Newtonian design are well-suited for observing planets, the Moon, and a wide range of deep-sky objects such as nebulae and galaxies.

5. Maintenance and Care

5.1 Cleaning Optics

• Dust on the primary mirror or corrector plate should be removed with a soft camel hair brush or a can of compressed air (held upright to prevent propellant discharge).
• For stubborn smudges or fingerprints, use a specialized optical cleaning solution and lens tissue. Apply the solution to the tissue, not directly to the lens, and wipe gently in a circular motion from the center outwards.
• Avoid touching optical surfaces with bare hands.

5.2 Storage

• Store the telescope in a dry, dust-free environment.
• Keep dust caps on the front of the telescope and the focuser when not in use.
• If storing for extended periods, consider using a padded case to protect against physical damage.

5.3 Collimation

Maksutov-Newtonian telescopes require occasional collimation (alignment of the optical elements) to maintain optimal image quality. Refer to advanced guides or contact Sky-Watcher support for detailed collimation procedures if you notice a degradation in image sharpness.

6. Troubleshooting

7. Specifications

8. Warranty and Support

For warranty information, technical support, or service inquiries, please contact Sky-Watcher customer service directly. Details can typically be found on the official Sky-Watcher website or through your authorized dealer.

Always refer to the manufacturer's official resources for the most current and accurate support information.