Vixen VMC260L MC 260/3000 OTA

Description

Operating at a 3000mm focal length with 0.45 arcseconds theoretical resolving power, the Vixen VMC260L MC 260/3000 OTA is a large-aperture modified maksutov-cassegrain telescope optical tube assembly built for lunar, planetary, and compact deep-sky observing. Featuring a 260mm (10.24 in) clear aperture and an f/11.5 focal ratio, this Japanese instrument gathers light to visual magnitude 13.8, resolving fine craterlet chains on the Moon, cloud details on Jupiter, and tight binary star systems.

The optical system features an open-tube modified Maksutov-Cassegrain design pairing a precision annealed Japanese Pyrex primary mirror with a two-element sub-aperture meniscus corrector lens placed ahead of the secondary mirror, treated with dielectric high-reflectivity coatings with a 33.5% central obstruction by diameter (11.2% by area). Built inside an aluminum chassis measuring 680mm in length with a 304mm outer tube diameter, the tube supplies 149.4mm of back focus from the rear mechanical thread (63.5mm from optional dedicated 0.62x reducers). Supported by a 2-inch dual-speed rack-and-pinion focuser with dual knobs, a tension brake, and an M60 accessory interface, this 10.00 kg (22.05 lbs) optical tube illuminates a 44mm full-frame image circle.

Key Features of Vixen VMC260L MC 260/3000 OTA

Designed for planetary video astrophotographers and visual observers seeking large 10.2-inch aperture without front-plate dew issues, this 260mm open-tube catadioptric pairs Pyrex optics with a dual-speed focuser. Heavy-duty aluminum end rings, an integral carrying handle, a wide dovetail plate, and an optical 7×50 finderscope deliver a dependable observing platform for heavy-capacity mounts.

• 260mm (10.24 in) clear aperture with 3000mm focal length and high-contrast f/11.5 optical speed
• Modified Maksutov-Cassegrain design with sub-aperture meniscus corrector ahead of secondary mirror
• Precision annealed Japanese Pyrex primary mirror with dielectric multi-layer coatings
• Open-tube chassis allowing rapid thermal equilibrium and preventing front corrector dew accumulation
• 2-inch dual-speed rack-and-pinion focuser with dual knobs, tension brake, and M60 threads
• Generous 149.4mm back focus distance from rear mechanical thread (63.5mm with 0.62x reducer)
• Corrected 44mm full-frame edge-to-edge image circle supporting large digital sensors
• Heavy-duty dovetail plate mounted to solid aluminum end rings, top handle, and 7×50 finder included

Sub-Aperture Meniscus Corrector & Pyrex Primary Mirror

The two-element sub-aperture meniscus corrector corrects spherical aberration and field curvature without requiring a full-diameter front glass plate, reducing weight and eliminating front dew formation. The low-expansion Japanese Pyrex primary mirror maintains optical figure stability across nocturnal cooling cycles, supporting practical visual and video magnifications from 37.1x up to 520x.

Dual-Rate Two-Inch Focuser & Solid Aluminum End Castings

Focusing precision is handled by a 2-inch dual-speed rack-and-pinion focuser featuring dual-rate knobs, an adjustable tension brake, and direct M60 accessory threading for optional focal reducers. The solid aluminum front and rear end rings provide high structural rigidity, while the 10.00 kg optical tube assembly balances smoothly via its wide dovetail plate on equatorial saddles.

• 2-inch dual-speed rack-and-pinion focuser with dual knobs and tension control for fine focal tuning
• Direct M60 threaded connection accommodating dedicated 0.62x focal reducers and imaging trains
• Cast-aluminum end rings with top carrying handle for balanced mount attachment and transport

Vixen VMC Large-Aperture Series Five-Year Warranty

The Vixen VMC260L MC 260/3000 OTA is backed by a 5-year limited warranty against material and manufacturing defects. The complete factory package contains the VMC260L optical tube, internal sub-aperture corrector group, heavy dovetail plate, top carrying handle, and a 7×50 optical finderscope with bracket.