FREE DELIVERY TODAY - 10% Discount for next 3 orders! Place your 1st order in.
Until the end of the sale:
00
days
00
hours
00
minutes
00
sec.
William Optics Fluorostar AP 120/780 Gold OTA Specs
| Brand | William Optics |
| Full Model Code | William Optics Fluorostar 120 Apochromatic Refractor Optical Tube Assembly - Gold Edition |
| Country of Origin | Taiwan (Design, Precision Engineering, Structural Fabrication, and Optical Assembly) |
| Optical Design | Apochromatic Refractor (3-Element Air-Spaced Triplet Lens Layout with fully baffled tube matrix) |
| Aperture | 120 mm (4.72 inches) |
| Focal Length | 780 mm |
| Focal Ratio | f/6.50 |
| Optical Coatings | Ultra-Pure Multi-Layer Anti-Reflective coatings (STM Coating) applied across all structural air-to-glass lens borders |
| Glass Material | Premium FPL-53 Synthetic Fluorite Extra-Low Dispersion (ED) Japanese Glass substrate paired with high-index matching lenses |
| Secondary Mirror Obstruction | 0 mm (Unobstructed Optical Path Setup) |
| Secondary Mirror Obstruction by Diameter | 0% |
| Secondary Mirror Obstruction by Area | 0% |
| Resolving Power | 0.97 Arcseconds (Dawes), 1.16 Arcseconds (Rayleigh) |
| Limiting Visual Magnitude | 12.2 |
| Highest Useful Magnification | 240x |
| Lowest Useful Magnification | 17x |
| Optical Tube Material | CNC-Machined High-Grade Aluminum Alloy Tube Body finished in powder-white with premium hard-anodized gold accent panels |
| Focuser Style & Mechanism | 3.3-inch Extra-Rigid Heavy-Duty Rack and Pinion Focuser featuring a 10:1 dual-speed micro-adjustment drive wheel |
| Mirror Lock Mechanism | No (Fixed structural lens elements prevent manual cell shifting or focus mechanics tilt) |
| Optical Tube Dimensions | 136 mm x 680 mm (Tube Outer Diameter x Minimum Collapsed Structural Length with retracted dew shield) |
| Optical Tube Weight | 7.20 kg (15.87 lbs) (Total weight rating inclusive of standard dual CNC tube rings and Losmandy-style dovetail bar assembly) |
| Mount Attachment Type | Dual CNC Heavy-Duty Mounting Rings linked to a standard large Losmandy-style D-Series Dovetail Mounting Plate |
| Finder Scope Specification | Integrated Patented Bahtinov Focus Mask configured inside the structural aluminum slide-out dew shield cap assembly |
| Included Accessories | 120mm Triplet Optical Tube, Dual CNC Tube Rings, CNC Saddle Handle Bar, Losmandy Dovetail Rail, Integrated Bahtinov Mask Cap |
| Standard Warranty | 2-Year Limited Warranty |
| Application | Advanced deep-sky astrophotography and extreme-contrast planetary tracking, bringing a substantial 4.7-inch color-free aperture to heavy tracking mounts. |






























Reviews
There are no reviews yet.