Bresser Telescope AC 90/500 Messier EXOS-1 (54601)

The Messier series by Bresser offers telescopes that provide excellent performance at an affordable price, making them ideal for ambitious beginners. These telescopes are designed to be expandable and retrofittable, ensuring they remain useful as users advance in their astronomy journey.

AC 90/500 Optics: A Compact and Versatile Telescope for Widefield Observations
The achromatic refractor AC 90/500 delivers impressive light-gathering performance with its 90mm aperture. Its 500mm focal length provides a wide field of view, making it ideal for observing open star clusters and the Milky Way. This combination makes the telescope suitable not only for beginners but also for experienced observers.

For those primarily interested in observing the Moon and planets, a telescope with a longer focal length, such as the AC 90/900, would be more appropriate.

The included accessories allow you to start sky observation immediately after unpacking. For terrestrial observation, it is recommended to purchase an Amici prism as an additional accessory.

Bresser EXOS-1 Mount
The EXOS-1 mount is designed for smaller optics and can support up to 7 kg without vibration or instability. It provides a stable platform for precise observations and can be optionally upgraded with a motor for the RA-axis to enhance tracking capabilities.

Included with the Mount:

• Sturdy equatorial mount

• Counterweight included

• Robust steel tripod with three legs

Specifications

Optics:

• Type: Refractor

• Type of build: Achromat

• Aperture: 90 mm

• Focal length: 500 mm

• Aperture ratio (f/): 5.5

• Resolving capacity: 1.28 arcseconds

• Limit magnitude: 11.6

• Light gathering capacity: 170x (compared to the naked eye)

• Maximum useful magnification: 180x

• Tube material: Aluminium

• Tube weight: 1.9 kg

• Tube construction: Full tube

Focuser:

• Type of build: Gear rack focuser

• Connection to eyepiece: 1.25"

Mount:

• Mounting type: Equatorial (EXOS-1 mount)

• Load capacity: Up to 7 kg

• GoTo control: No

Tripod:

• Material: Steel tripod with accessory plate included

• Type: Tripod

Included Accessories:

• Eyepiece (1.25"): SPL 26 mm included

• Finder scope: 6x30 finder scope included

• Deviating optics: 1.25", 90° star diagonal included

• Dew shield included

• Prism rail: Vixen-style prism rail included

• Slow-motion cable included

Miscellaneous:
Polar finder scope not included; finder base compatible with Meade/Explore Scientific T-profile

General Information:

• Series: Messier series by Bresser

• Total weight (including mount and tripod): Approximately 12 kg

Area of Application:

• Moon & Planets Observation: Yes

• Nebulae & Galaxies Observation: Yes

• Astrophotography: No

• Nature Observation: No

• Sun Observation: No (only with an appropriate solar filter)

Recommended For:

• Beginners: Yes

• Advanced users: No

• Observatories: No