William Optics Pleiades 181/998 APO Septuplet Astrograph OTA

Pleiades 181: Seven-element astrophotograph for full frame

The William Optics Pleiades 181 is a pure astrograph, built around a seven-element optical design with FPL-53 glass and integrated corrector. Stars remain sharp points even in the corners of a full-frame sensor, without a separate flattener. The absolute top model: 181 mm aperture in a corrected seven-element system, for observatory-class results.

Fast system, short exposures

With a 181 mm aperture and a 998 mm focal length (f/5.5), this is a fast photographic system: lots of signal in a short time, allowing for deeper exposures per night. The included camera adapters directly connect common phototrains, and the Bahtinov mask allows for precise focusing. This is a camera instrument: visual use with eyepieces is not what this tube is designed for.

In the box

• Optical tube Pleiades 181/998 with seven-element optics
• 3.7 inch rack-and-pinion focuser
• Integrated corrector
• M48-, M54-, and M68-camera adapters
• Losmandy dovetail
• Handle
• Bahtinov mask
• Transport bag

Featured accessories

A William Optics UniGuide Guiding Scope completes the setup for long exposures; choose the size that fits your mount and camera.

For whom yes, for whom no

For the demanding astrophotographer with an observatory or heavy-duty permanent setup seeking refractor-class perfection. Not for almost anyone else; this is a small observatory-class instrument with corresponding mount requirements.

Specifications

Unsure about the right tube for your camera and mount? The telescope selection aid helps you choose. Also view all Refracting telescopes and the full range of William Optics.