Askar 71F Quadruplet Flat-Field APO f/6.9

The Askar 71F Quadruplet Flat-Field APO f/6.9 is a high-performance apochromatic refractor telescope specifically designed for wide-field astrophotography. With its 71mm aperture and fast f/6.9 focal ratio, this telescope offers an excellent balance of light gathering power and field of view, making it ideal for capturing expansive deep-sky objects and star fields.

Optimized for astrophotography. Additional accessories may be required for visual use. Check compatibility with your existing imaging equipment.

Optical Design

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The 71F features a sophisticated quadruplet lens design, incorporating four precisely aligned elements to deliver superior color correction and a flat field. This apochromatic design effectively eliminates chromatic aberration and field curvature, ensuring sharp, high-contrast images across the entire field of view, which is crucial for astrophotography.

Imaging Performance

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With its 71mm aperture and 490mm focal length (f/6.9), the 71F excels in wide-field astrophotography. It's particularly well-suited for capturing large nebulae, extensive star fields, and expansive galaxy groups. The fast f/6.9 focal ratio allows for shorter exposure times, making it easier to gather data even under less-than-ideal sky conditions.

Flat-Field Design

The flat-field design of the 71F ensures that stars remain sharp and pinpoint from the center to the edges of the frame. This is particularly beneficial for astrophotographers using large sensors, as it eliminates the need for a separate field flattener.

Build Quality

Constructed with high-quality materials, including a precision-machined aluminum tube and dew shield. The robust build ensures stability and minimizes flexure, critical for long-exposure astrophotography. The retractable dew shield adds to its portability.

Focuser

Equipped with a high-precision dual-speed focuser, allowing for fine adjustments necessary for achieving perfect focus in astrophotography. The focuser is designed to handle heavy imaging payloads without slipping, ensuring consistent performance throughout long imaging sessions.

Portability

With its compact size and lightweight design, the 71F is highly portable, making it an excellent choice for astrophotographers who frequently travel to dark-sky sites. Its portability doesn't compromise its optical performance, offering a perfect balance for mobile imaging setups.

Versatility

While primarily designed for astrophotography, the Askar 71F can also be used for visual observations with appropriate accessories. It offers breathtaking wide-field views of star fields, nebulae, and larger deep-sky objects, making it a versatile instrument for various astronomical pursuits.