Wide-field imaging, packed smaller. The FSQ-85EDX brings the FSQ-106EDX4's wide-field deep sky pedigree into a more mobile package, built for imagers who want that flat, wide field without hauling a bigger tube.
A quadruplet that means business. The apochromatic Petzval quadruplet design, built with ED glass, delivers a 450 mm focal length and a genuinely flat field across 5.6 degrees of sky, the kind of coverage wide-field imagers chase.
Ready for today's sensors, out of the box. It ships with a 1.01X corrector built to make the most of modern, smaller-pixel sensors, holding a 44 mm image circle for edge-to-edge sharpness.
A focuser built to be trusted. The rack-and-pinion focuser is deliberately oversized and driven by a dual 1/7 ratio wheel system for precise, repeatable focus, and comes with a CAA (Camera Angle Adjuster) built in for easy photographic framing.
Packs down when you need it to. A retractable dew shield saves space in the case without giving up protection in the field.
Turn it into a telephoto lens. Add the optional focal reducer and the FSQ-85EDX becomes a high-end 328 mm astronomical telephoto at F/3.9, with a 7 degree field of view and a 40 mm image circle.
Precision hardware from a name astrophotographers trust. Like everything else Takahashi builds, the FSQ-85EDX is engineered to deliver night after night, whether you're framing a wide starfield or reaching in for more focal length.
Specifications
Objective: Petzval Quadruplet with ED glass
Lens Cell: Highly air-spaced quadruplet, 4 lenses in 4 groups, with 2x S-FPL53 ED lenses
Coatings: Hard multicoatings
Diameter: 85 mm
At Prime Focus
Focal Length: 450 mm
Focal Ratio: F/5.3
Metal Back Distance: 197.5 mm
With 1.01X Field Corrector
Focal Length: 455 mm
Focal Ratio: F/5.4
Image Circle Diameter: 44 mm
Metal Back Distance: 56.2 mm
With RD QE0.73X Focal Reducer
Focal Length: 327 mm
Focal Ratio: F/3.8
Image Circle Diameter: 44 mm
Metal Back Distance: 72.2 mm
With EX ED1.5X Focal Extender
Focal Length: 680 mm
Focal Ratio: F/8
Image Circle Diameter: 44 mm
Metal Back Distance: 117.5 mm
Optical Tube
Length: 623 mm (535 mm with dew shield retracted)
Tube Diameter: 95 mm
Dew Shield Diameter: 114 mm
Weight: 3.6 kg
Focuser: Rack-and-pinion with 1/7 microfocuser
What's in the Box?
FSQ-85EDX Optical Tube Assembly x1
1.01X Field Corrector x1
Note: The RD QE0.73X focal reducer and EX ED1.5X focal extender are optional accessories, sold separately.