Airy Disk APO 204mm f/7 Triplet ED FK61 Apochromatic Refractor APO

This 8-inch Airy Disk triplet APO uses H-FK61/CDGM glass in a 204mm f/7 refractor design with a 1428mm focal length. It is built for high-end visual observers and deep-sky imagers who need serious aperture, resolution, and corrected optical performance.

The 204mm platform includes full wideband multi-coating, Losmandy mounting hardware, a 4-inch dual-speed rack-and-pinion focuser, and reducer/flattener compatibility for full-frame imaging systems.

Specifications

• SKU: 204APO
• Glass used: H-FK61 CDGM
• Aperture: 204mm
• Focal ratio: f/7
• Focal length: 1428mm
• Coating: full wideband multi coating
• Resolving Power: 0.57"
• Limit magnitude: 13.3mag
• Tube material: Aluminum alloy
• Dovetail style: Losmandy
• Focuser: 4" dual-speed 1:10 rack-and-pinion
• Available reducers/flatteners: 0.8x FF, 0.92x FF
• Reduced focal length: 1142mm f/5.6
• Sensor coverage: Full Frame
• Eyepiece clamp: 2" with 1.25" Adapter
• Length extended: 1563mm
• Length hood in: 1332mm
• OTA weight: 19.455kg
• Aluminum case: included
• Tube thread: M201x1.5

The Airy Disk APO 204mm f/7 Triplet ED FK61 Apochromatic Refractor APO is built for astronomers who want a premium apochromatic refractor for visual observing, deep-sky imaging, planetary viewing, and portable astrophotography. With carefully selected ED glass, precision mechanics, and wideband multi-coated optics, this Airy Disk telescope is positioned for sharp contrast, refined color correction, and dependable performance under the night sky.