Askar 150PHQ Quadruplet Astrograph

Askar 150PHQ Quadruplet Astrograph

151PHQ — Where Engineering Meets Celestial Sublime

The 151PHQ marks a major milestone in the Sharpstar lineup: the largest refractor ever built by the brand, crafted for those who want to capture the universe with power, finesse, and simplicity. Here, high-end astronomy finally sheds its constraints: no external flattener, no backfocus calculations, no tedious assembly. Install your imaging accessories, focus, and the optics reveal a perfectly flat field ready to immortalize the sky.

Its 151 mm aperture delivers exceptional light-gathering capability, more resolution, more contrast, more detail in compact nebulae, distant galaxies, or globular clusters. With its 1057 mm focal length at f/7, the 151PHQ belongs to the category of instruments designed to reveal the intimate structure of space.

Its quadruplet optical design with two ED glass elements effectively corrects chromatic aberration, suppresses off-axis distortions, and produces remarkably pure star images. Thanks to its integrated flat-field optical system, the 151PHQ supports a 60 mm image circle suitable for medium-format sensors while maintaining a central RMS radius under two microns, a striking signature of precision.

The mechanical design matches this ambition:

• telescopic dew shield
• high-precision CNC-machined tube
• durable anodized finish
• refined details that highlight controlled power

Its rigid 3.4″ focuser with 360° rotator and M68 / M54 / M48 adapters ensures secure mounting, even with heavy imaging gear. Combined with the 3″ 0.7× reducer, it transforms into a 740 mm f/4.9 system, dramatically shortening exposure times while widening the field, ideal for large objects or rapid mosaics.

Its multifunction handle with central M6 slot, 300 mm Losmandy dovetail plate, and robust tube rings provide stability and confidence under the night sky.

The 151PHQ is more than an instrument:
it is a companion designed to unveil the invisible structures of the cosmos, built for demanding enthusiasts, capable of capturing the sky with majesty while remaining effortless to operate.

151PHQ Specifications

• Aperture diameter: 151 mm
• Focal length: 1057 mm
• Focal ratio: f/7
• Objective: quadruplet air-spaced APO including two ED glass elements
• Image circle: 60 mm

Maximum accessory connection (focuser fully retracted)

• Imaging mode: 78 mm from the base of the M48×0.75 thread
• Observing mode: 119 mm from the end of the 1.25″ eyepiece holder

Total length

• Observing mode: 930.3 mm dew shield retracted / 1117.8 mm dew shield extended
• Imaging mode: 976.8 mm dew shield retracted / 1164.3 mm dew shield extended

• OTA weight: 11.6 kg
• Total weight with tube rings and dovetail: 13.7 kg

Rear thread types

• M86×1 to M68×1
• M68×1 to M54×0.75
• M54×0.75 to M54×0.75
• M54×0.75 to M48×0.75 with internal M48×0.75 filter thread
• Four-piece photographic adapter thread: M48×0.75

Standard package contents

• 151PHQ OTA
• Pair of tube rings
• Handle
• Askar Losmandy-type 300 mm dovetail plate
• Set of four photographic adapters
• Aluminium case
• Manual