• Air Spaced Apochromatic Triplet
• FPL-53 extra low dispersion glass
• Zero detectable colour fringing even on bright objects
• Diffraction limited optics
• Fully multi coated lenses
• 3″ CNC machined 11:1 dual speed linear power focuser – rotatable
• Indexed focuser tube
• Knife-edge baffled system to enhance contrast

The Sky-Watcher 150mm Esprit 150ED Triplet APO Refractor is a professional instrument for the most demanding and exacting astro-photographers. The air spaced apochromatic triplet lenses use the remarkable Ohara FPL-53 ED (extra low dispersion) glass, with exceptional colour correction over the entire visible spectrum there is no chromatic aberration even on bright objects! Knife edge baffles reduce internal reflections and increase contrast, helping to bring out faint structure in deep sky objects.

A 2-element field flattener is included to iron out the natural off-axis astigmatism and field curvature of the objective lens, leaving a fully corrected 42mm field of view. The Sky-Watcher exclusive Helinear Track 11:1 dual speed focuser is rock solid with zero image shift and a 3″ barrel to avoid vignetting. Designed with photography in mind, it sits on two tracks above and below the barrel to prevent flexure with a heavy camera attached, and is fully rotatable to perfectly frame a target on the sensor.