Omegon Maksutov MC 90/1250 OTA Telescope Instruction Manual

1. Introduction

This manual provides essential information for the safe and effective use of your Omegon Maksutov MC 90/1250 OTA Telescope. This compact and versatile optical tube assembly (OTA) is designed for both astronomical and terrestrial observations, offering clear views of celestial bodies like the Moon and planets, as well as distant wildlife and landscapes.

The Maksutov-Cassegrain design provides a long focal length in a short optical tube, making it highly portable and easy to set up. Its 90mm objective diameter and multi-coated optics ensure bright, high-contrast images.

Figure 1: Side view of the Omegon Maksutov MC 90/1250 OTA Telescope, showcasing its compact design.

2. Safety Information

Please read and understand all safety instructions before using your telescope. Failure to follow these instructions may result in injury or damage to the product.

• Never look directly at the Sun through the telescope or finderscope without a certified solar filter. Doing so will cause immediate and permanent eye damage, including blindness.
• Do not leave the telescope unattended in direct sunlight, as it can concentrate sunlight and cause fires.
• Handle the optical tube with care to avoid dropping or impacting it, which can damage the precision optics.
• Keep the telescope away from small children to prevent accidental injury or damage to the equipment.
• Store the telescope in a dry, dust-free environment when not in use.

3. Package Contents

Your Omegon Maksutov MC 90/1250 OTA Telescope package includes the following items:

• Omegon Maksutov MC 90/1250 Optical Tube Assembly (OTA)
• 8x21 Reflex Finderscope
• Protective Dust Caps
• Transport Backpack

Important Note:

Eyepieces and a compatible tripod or mount are not included with this Optical Tube Assembly (OTA) and must be purchased separately to use the telescope. The telescope is compatible with standard 1.25-inch eyepieces and mounts featuring a Great Polaris (GP) rail.

Figure 2: The included transport backpack, designed for convenient portability of the telescope.

4. Setup

Follow these steps to prepare your Omegon Maksutov MC 90/1250 OTA for observation.

1. Unpack the Telescope: Carefully remove the optical tube and finderscope from the transport backpack.
2. Attach the Finderscope: Locate the mounting bracket for the 8x21 reflex finderscope on the top of the main optical tube. Slide the finderscope into the bracket and secure it with the provided thumbscrews. Ensure it is firmly attached but do not overtighten.

Figure 3: Top view of the telescope, showing the attached finderscope and focuser knob.
3. Mount the Optical Tube: Attach the telescope to a compatible tripod or mount. The MC 90/1250 OTA features a Great Polaris (GP) rail for easy attachment to various astronomical mounts. Ensure the telescope is securely fastened to prevent accidental drops.


Figure 4: The Omegon Maksutov MC 90/1250 OTA mounted on a compatible tripod (tripod not included).

4. Insert an Eyepiece: Remove the dust cap from the focuser. Insert a 1.25-inch eyepiece (purchased separately) into the focuser and secure it with the thumbscrew.


Figure 5: Rear view of the telescope, highlighting the focuser and the port for eyepiece insertion.

5. Remove Dust Caps: Remove the dust cap from the front objective lens of the telescope and from the finderscope.

Figure 6: Front view of the telescope, showing the objective lens and its protective dust cap.
6. Align the Finderscope: Before observing, align the finderscope with the main telescope. Point the main telescope at a distant, stationary object (e.g., a distant tree or building, never the sun). Look through the main telescope and center the object in the field of view. Then, look through the finderscope and adjust its alignment screws until the same object is centered in the finderscope's crosshairs.

5. Operating the Telescope

Once your telescope is set up and the finderscope is aligned, you are ready to begin observing.

Astronomical Observation

1. Locate Your Target: Use the finderscope to locate the celestial object you wish to observe. The finderscope provides a wider field of view, making it easier to pinpoint objects.
2. Center the Object: Once the object is visible in the finderscope, use your mount's controls to center it.
3. Observe Through the Main Telescope: Look through the eyepiece of the main telescope. The object should now be visible within the field of view.
4. Focus: Use the focuser knob (manual focus) to achieve a sharp image. Turn the knob slowly until the image is clear.
5. Changing Magnification: To change magnification, remove the current eyepiece and insert one with a different focal length. Lower focal length eyepieces provide higher magnification.

Figure 7: Illustrative image of the Moon, demonstrating the detail visible through the telescope.

Terrestrial Observation

The Omegon Maksutov MC 90/1250 OTA is also suitable for terrestrial viewing. Follow the same steps as for astronomical observation, focusing on distant land objects.

Figure 8: Illustrative image of a bird, showcasing the telescope's capability for detailed terrestrial observation.

Using the Flip Mirror (if applicable)

The telescope features a flip mirror for photography and observation. Consult your mount and camera instructions for specific setup details when using this feature for astrophotography.

6. Maintenance

Proper care and maintenance will ensure the longevity and optimal performance of your telescope.

• Cleaning Optics: Dust on the objective lens or eyepiece can be removed with a soft brush or a can of compressed air. For fingerprints or stubborn smudges, use a specialized optical cleaning solution and a microfiber cloth designed for optics. Apply solution to the cloth, not directly to the lens.
• Cleaning the Tube: The exterior of the optical tube can be wiped with a soft, damp cloth. Avoid abrasive cleaners.
• Storage: Always replace dust caps on the objective lens and focuser when the telescope is not in use. Store the telescope in its transport backpack in a cool, dry, dust-free environment. Avoid extreme temperatures and humidity.
• Avoid Disassembly: Do not attempt to disassemble the optical tube or its components. This can void your warranty and cause permanent damage to the precision optics.

7. Troubleshooting

If you encounter issues with your telescope, refer to the following common problems and solutions:

• No Image or Blurry Image:
  • Ensure all lens caps are removed from the objective lens and eyepiece.
  • Adjust the focuser knob slowly until the image is sharp.
  • Verify an eyepiece is correctly inserted and secured.
  • Check if the finderscope is properly aligned with the main telescope.
• Difficulty Finding Objects:
  • Ensure the finderscope is accurately aligned with the main telescope.
  • Start with a low-magnification eyepiece (longer focal length) for a wider field of view.
• Image Appears Distorted or Aberrated:
  • Ensure the telescope has acclimated to the ambient temperature, especially when moving from a warm indoor environment to a cold outdoor one.
  • Check for any obstructions in the light path (e.g., dew, dust, or internal components).
  • If persistent, contact customer support for assistance.

8. Specifications

9. Warranty Information

This Omegon Maksutov MC 90/1250 OTA Telescope comes with a 24-month manufacturer's warranty from the date of purchase. This warranty covers defects in materials and workmanship under normal use. It does not cover damage resulting from misuse, accident, unauthorized modification, or improper maintenance.

Please retain your proof of purchase for warranty claims.

10. Customer Support

For technical assistance, troubleshooting beyond this manual, or warranty inquiries, please contact Omegon customer support. You can typically find contact information on the official Omegon website or through your retailer.

When contacting support, please have your model number (MC 90/1250 OTA) and proof of purchase readily available.