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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Askar 1x Field Flattener for 103APO
Askar 1x Field Flattener for 103APO

Askar 1x Field Flattener for 103APO

by Askar
SKU ASK-ASKFL10310
$219.00 - $219.00
$219.00
$219.00 - $219.00
$219.00
Price Match Policy!
  • Corrects field curvature and coma for the Askar 103APO
  • Maintains the native 700.4mm focal length and f/6.8 ratio
  • Triplet optical design delivers sharp stars edge-to-edge
  • Provides a 44mm full-frame corrected image circle
  • Standard 55mm back focus from the M48 thread
  • Includes M54 and M48 camera adapters and a 2" filter thread
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Askar 1x Field Flattener for 103APO

    The Askar 1x Field Flattener is engineered specifically for the 103APO refractor, correcting field curvature across a 44mm full-frame image circle while maintaining the telescope's native 700.4mm focal length and f/6.8 focal ratio. This 0.58kg flattener utilizes a triplet optical design to deliver sharp stars to the edge of the frame and integrates into any standard imaging train with 55mm of back focus from its M48 male thread.

    A 44mm Flat Field for the Askar 103APO

    This flattener's primary function is to eliminate the field curvature and coma inherent in a refracting telescope, ensuring star points remain perfectly round across the entire sensor. The triplet air-spaced lens design achieves this correction over a 44mm image circle, making it an essential accessory for imagers using full-frame DSLR, mirrorless, or dedicated astronomy cameras with the Askar 103APO.

    By using a 1x magnification factor, the flattener preserves the telescope's native 700.4mm focal length and f/6.8 focal ratio. This allows you to capture wide-field targets with the maximum resolution and light-gathering power the 103APO optics can provide, but with the critical addition of a perfectly flat field.

    55mm Back Focus and Standardized Connections

    Askar designed this flattener for seamless integration into modern imaging setups. It provides the industry-standard 55mm of back focus measured from the base of its male M48x0.75 thread, which simplifies connecting most cameras and filter wheels without complex calculations. Simply add your camera's T-ring or standard spacers to reach the 55mm distance for optimal performance.

    • Versatile Adapters: The camera side includes both M54×0.75 and M48×0.75 threaded adapters, providing direct attachment for a wide range of cameras, filter drawers, and off-axis guiders.
    • Integrated Filter Cell: A built-in M48x0.75 thread inside the adapter acts as a 2-inch filter cell, allowing you to mount light pollution or narrowband filters directly within the flattener itself.
    • Robust Build: The entire housing is CNC-machined for precise optical alignment and weighs a solid 0.58kg, ensuring no flexure in the imaging train.

  • What is the main purpose of the Askar 1x Flattener for the 103APO?

    The Askar 1x Flattener is designed to correct optical aberrations like field curvature and coma in the Askar 103APO telescope. This ensures that stars are sharp and point-like across the entire imaging sensor, which is crucial for astrophotography, especially with large-format cameras.

    Does the Askar 1x Flattener change the 103APO's focal length?

    No. As a 1x flattener, it does not reduce or extend the focal length. When attached to the Askar 103APO, the telescope maintains its native 700.4mm focal length and f/6.8 focal ratio, simply delivering a corrected, flat field of view.

    What cameras are compatible with the Askar 1x Flattener's 55mm back focus?

    The standard 55mm back focus is compatible with most imaging systems. This includes:

    • DSLR and mirrorless cameras with a standard T-ring adapter.
    • Dedicated astronomy cameras when combined with the appropriate spacers to achieve the 55mm distance.
    The flattener includes both M54 and M48 threads to connect to a wide variety of accessories.

    Can I use 2-inch filters with the Askar 1x Flattener for the 103APO?

    Yes. The Askar 1x Flattener has a built-in M48x0.75 filter thread on the camera side. This allows you to directly screw in standard 2-inch astronomy filters for light pollution suppression or narrowband imaging.

    How does the Askar 1x Flattener improve images of the Andromeda Galaxy (M31) with the 103APO?

    A large target like the Andromeda Galaxy (M31) will stretch across the entire field of a full-frame sensor when imaged with the Askar 103APO. Without this flattener, stars at the edges of the galaxy would appear elongated or out of focus. The Askar 1x Flattener ensures that the outer spiral arms and surrounding star fields of M31 are just as sharp as the galactic core.

    Will the Askar 1x Flattener fully illuminate my full-frame sensor on an f/6.8 system?

    Yes. The flattener is specifically designed to produce a corrected and illuminated 44mm image circle. This is large enough to cover a standard full-frame sensor (which has a 43.3mm diagonal) without vignetting, making it a perfect match for the Askar 103APO's f/6.8 optics.

  • Optical Design 3-Element Air-Spaced (Triplet)
    Magnification 1x
    Compatible Telescope Askar 103APO
    Focal Length with 103APO 700.4mm
    Focal Ratio with 103APO f/6.8
    Corrected Image Circle 44mm
    Back Focus 55mm (from M48x0.75 male thread base)
    Camera-Side Threads M54x0.75 & M48x0.75
    Internal Filter Threads M48x0.75 (2-inch)
    Weight 0.58 kg
  • Askar 1-Year Warranty