Bresser AC 90/500 Messier Refractor OTA

Description

Setting up in minutes, the Bresser AC 90/500 Messier Refractor OTA is a 1.9kg short-tube achromat at f/5.6 built for a quick weeknight look at the Moon and wide star fields alike. This version ships as a bare optical tube with no mount included, for observers who already own a compatible mount or want a lightweight second scope for an existing rig, and its universal Vixen-style dovetail bar fits most standard mount heads without needing a separate adapter plate.

At just 1.9kg, this tube pairs easily with a mount already rated for a similar-aperture refractor, and the integrated piggyback camera mount on the tube rings adds real flexibility beyond simple visual use: ride it alongside a primary telescope for wide-field guiding, or use it standalone for grab-and-go sessions when packing light matters more than raw aperture. The 2.5-inch Hexafoc heavy-duty focuser handles a diagonal and eyepiece steadily even under a light camera’s weight, something a basic rack-and-pinion focuser at this price point often struggles to manage without slipping under load.

Key Features of Bresser AC 90/500 Messier Refractor OTA

A 90mm achromatic objective in a short-tube configuration keeps this scope compact without sacrificing the wide, bright fields f/5.6 is known for, making it a genuinely versatile starting point for a second optical tube.

• Universal Vixen-style dovetail bar with stainless steel rail protection fits most existing mounts
• Integrated piggyback camera mount lets this tube ride alongside a primary telescope
• 2.5-inch Hexafoc heavy-duty focuser handles a camera’s weight without slipping
• Tube rings with a built-in carrying handle make solo transport straightforward
• At 1.9kg, this is light enough for a small existing mount to carry easily
• 6×30 optical finder scope helps locate targets before switching to the main eyepiece
• Short 500mm focal length keeps cooldown time minimal even on a cold night

What Sets the AC 90/500 OTA Apart

Every other version of this optical tube in the Messier 90/500 line comes bundled with a specific mount. This OTA-only version is for the buyer who already has one, or wants a second, lightweight optical tube to run alongside a main imaging setup via the piggyback mount. The optics inside are identical to every bundled version in this catalog — what you’re choosing here is flexibility, not a different telescope, and that distinction matters most to observers who already understand what mount their existing setup can carry.

Applications & Use Cases

Built as a compact standalone optical tube, this scope suits wide-field tracking, grab-and-go setups, or dual-telescope guiding configurations for observers who already have a mount ready to receive it and want to expand their existing setup rather than start from scratch.

• Observers who already own a compatible mount and just need the optical tube
• Imagers wanting a lightweight second scope for wide-field guiding
• Travelers who want a compact backup tube that packs down small

Bresser Warranty & Support

The AC 90/500 OTA carries a 2-Year Factory Warranty covering manufacturing defects, handled directly through Bresser’s support channel with no third party involved in the claims process, so a defective part gets resolved directly with the manufacturer.