NAKOH 92GX 92/598 mm f/6.5 Quintuplet Petzval APO apochromatic telescope (NAKOH, SKU: 92GX) is a five-element apochromatic refractor designed for deep-sky astrophotography and visual observation. The Petzval optical system with a front triplet and rear doublet provides a flat 55 mm image circle without requiring an additional field flattener. The use of Japan-made SD glass and ED glass reduces chromatic aberration and allows sharp images to be obtained across the entire supported field.

Key features

• five-element Quintuplet Petzval APO optical system with an air-spaced front triplet and rear doublet
• one Japan-made SD glass element and one ED glass element
• flat 55 mm image circle, also suitable for medium-format sensors
• imaging without an additional field flattener
• multi-layer optical coatings reducing reflections and stray light
• 3.2" metal dual-speed rack-and-pinion focuser with 43 mm travel
• precision 360° rotator with an engraved scale and position lock
• retractable dew shield facilitating transport and storage
• clamshell tube ring and handle with M4 and M6 threaded holes
• 300 mm Vixen and Losmandy mounting plates
• M48 and M54 imaging adapters allowing the camera connection method to be selected

Set contents

• NAKOH 92GX optical tube assembly
• carrying handle
• tube ring
• 300 mm Vixen mounting plate
• 300 mm Losmandy mounting plate
• 1.25" eyepiece adapter
• 2" eyepiece adapter
• four-piece imaging adapter set
• M54 imaging adapter
• focuser knob cap
• user manual
• warranty card

Technical specifications

• telescope type: apochromatic refractor
• optical design: five-element Quintuplet Petzval APO
• lens configuration: air-spaced front triplet and rear doublet
• optical glass: 1 Japan-made SD element, 1 ED element
• objective diameter: 92 mm
• focal length: 598 mm
• focal ratio: f/6.5
• corrected image circle diameter: 55 mm
• resolving power: 1.26"
• limiting magnitude: 11.57 mag
• light-gathering power: 172× greater than the unaided eye
• focuser type: 3.2" metal dual-speed rack-and-pinion focuser
• focuser travel: 43 mm
• rotator: 360° with scale and locking mechanism
• visual connections: 1.25" and 2"
• imaging connections: M48 × 0.75 and M54 × 0.75
• filter thread: 2" in the M48 adapter
• focusing range for visual observation: 73–116 mm
• focusing range for astrophotography: 37–80 mm
• tube length with retracted dew shield: 502 mm
• tube length with extended dew shield: 588 mm
• optical tube weight: approximately 5.24 kg
• weight with tube ring and mounting plate: approximately 6.88 kg

The NAKOH 92GX combines a wide, flat image field with an extensive mounting and adapter system, allowing it to serve both as an astrograph for large-sensor cameras and as a telescope for demanding visual observations.