Askar 151PHQ f/7 Quadruplet Astrograph

151mm f/7 Quadruplet APO Optics with 2 ED Elements

The heart of the 151PHQ is its air-spaced quadruplet objective, which uses two extra-low dispersion (ED) glass elements to achieve apochromatic correction. This design aggressively suppresses chromatic aberration, ensuring stars are rendered as sharp, color-pure points without distracting halos. At 151mm of aperture and a 1057mm focal length, this instrument captures faint details on galaxies and nebulae with high resolution, making it ideal for serious deep-sky imagers.

A 60mm Flat Field: No External Flattener Required

Unlike traditional refractors, the 151PHQ features a built-in field flattener as part of its core optical design. This Petzval-like configuration produces a corrected, flat 60mm image circle, fully illuminating large full-frame and medium-format sensors without any additional hardware. You can attach your camera directly via the included adapters and start imaging, confident that stars will remain round and sharp from the center to the corners of your frame.

Imaging-Ready Mechanics: 13.7kg OTA with a 3.4" Focuser

Engineered for stability, the 151PHQ weighs 11.6kg as an OTA and 13.7kg fully equipped with its tube rings and 300mm Losmandy-style dovetail plate. This substantial build requires a high-capacity mount but rewards you with a rigid imaging platform. The heavy-duty 3.4-inch rack-and-pinion focuser provides precise, no-slip control over focus, even with heavy camera payloads, and includes a 360° rotator for effortless image framing.

• Telescopic Dew Shield: Contracts the OTA length to 930.3mm for transport and extends to 1117.8mm to block stray light and prevent dew formation.
• CNC-Machined Tube: The entire optical tube is built for rigidity and thermal stability, ensuring focus remains consistent throughout an imaging session.
• Finder Base: A standard finder shoe is included for attaching your preferred guide scope or finder.

Complete Mounting & Connection System: 300mm Plate and 4 Adapters

The 151PHQ arrives ready to integrate into your setup. It includes a pair of robust tube rings, a multi-function carrying handle, and a 300mm Losmandy-style dovetail plate for secure attachment to your mount. To connect your camera, a set of four threaded adapters is provided, stepping down from the focuser's native M86x1 thread to the universal M48x0.75 thread used by most cameras and filter wheels.

Askar 151PHQ vs. 130PHQ: Aperture and Portability

As the largest instrument in Askar's PHQ line, the 151PHQ is the direct successor to the popular 130PHQ for imagers seeking more resolving power and light grasp.

• Askar 130PHQ Advantage: The 130PHQ is significantly lighter and more compact. Its lower weight makes it compatible with a wider range of medium-payload mounts, offering greater portability.
• Askar 151PHQ Advantage: With a 151mm objective, the 151PHQ gathers 34% more light than the 130mm model, allowing you to capture fainter details or reduce exposure times. Its longer 1057mm focal length also provides greater image scale, making it better suited for resolving details in smaller galaxies and planetary nebulae.