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Askar FMA180 Pro 180mm f/4.5 APO Full Frame Lens

Askar FMA180 Pro 180mm f/4.5 APO Full Frame Lens

by Askar
SKU ASK-FMA180
CA$615.00 - CA$615.00
CA$615.00
CA$615.00 - CA$615.00
CA$615.00
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  • 40mm Aperture Sextuplet APO Lens
  • 180mm Focal Length at a Fast f/4.5
  • 44mm Image Circle for Full-Frame Sensors
  • Standard 55mm Back Focus with M48x0.75 Threads
  • Integrated 360° Rotator and Internal Focuser
  • Lightweight 0.8kg Design
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Askar FMA180 Pro 180mm f/4.5 APO Full Frame Lens

    The Askar FMA180 Pro lens integrates a 40mm sextuplet APO optical system into a compact astrograph, delivering a fast f/4.5 focal ratio and a 180mm focal length for wide-field imaging. Its air-spaced design incorporates two ED glass elements to produce sharp, color-corrected stars across a 44mm image circle, fully illuminating full-frame sensors. Weighing just 0.8kg and measuring 167.5mm in length, the FMA180 Pro provides a standard 55mm back focus for seamless integration into your existing imaging train.

    Sextuplet f/4.5 APO Optics: A 44mm Full-Frame Image Circle

    The FMA180 Pro's optical core is a six-element apochromatic design with two extra-low dispersion (ED) elements, engineered specifically for astrophotography. This configuration provides excellent chromatic aberration control, ensuring pinpoint stars without color fringing. The fast f/4.5 focal ratio allows you to capture significant signal in shorter sub-exposures, reducing demands on your tracking mount.

    With a 44mm image circle, this lens is built to serve modern full-frame CMOS and DSLR cameras. You can capture vast targets like the Andromeda Galaxy (M31) or the Rho Ophiuchi cloud complex without the vignetting or field curvature issues that plague lenses not designed for astrophotography.

    Pro Astrograph Design: Internal Focusing and a 360° Rotator

    The "Pro" designation signifies key mechanical upgrades for imagers. The internal focusing mechanism moves lens elements internally, eliminating drawtube sag and tilt that can occur with external focusers, especially when supporting heavy filter wheels and cameras. This ensures a rigid, stable optical train throughout your imaging session.

    An integrated 360° rotator allows for precise framing of your target without rotating your entire camera and cable assembly. The OTA also includes a multi-functional finder base and a Vixen-style dovetail plate, allowing it to be used as a primary imaging scope, a high-end guide scope, or a compact visual instrument.

    FMA180 Pro vs. FMA180: Key Upgrades for Imaging

    While sharing the same core optics as its predecessor, the FMA180 Pro introduces several critical enhancements for astrophotography. These upgrades address the practical needs of remote and automated imaging.

    • Internal Focuser: The Pro model's internal focusing design provides superior stability and focus retention compared to the external focuser of the standard FMA180. This is a significant advantage for automated focusing routines.
    • 360° Rotator: The addition of a dedicated rotator makes framing targets dramatically easier, a feature absent on the original model.
    • Finder Base: An integrated finder-style mounting base adds versatility for attaching guide scopes or other accessories directly to the OTA.

  • What makes the Askar FMA180 Pro suitable for full-frame cameras?

    The Askar FMA180 Pro is designed with a corrected 44mm image circle. This is large enough to fully illuminate the sensors of full-frame cameras (typically 43.3mm diagonal) without significant light fall-off or distortion at the corners.

    How would the FMA180 Pro perform on the North American Nebula (NGC 7000)?

    The 180mm focal length is an excellent match for very large emission nebulae. Paired with a full-frame camera, the FMA180 Pro can capture the entire North American Nebula (NGC 7000) and the adjacent Pelican Nebula (IC 5070) in a single frame with high resolution.

    What is the benefit of the internal focusing on the FMA180 Pro?

    Internal focusing provides superior mechanical stability. Because no external drawtube moves, it prevents potential sag or tilt, which is critical for maintaining a flat field with heavy cameras and filter wheels. It also ensures the overall length of the instrument remains fixed at 167.5mm, simplifying cable management.

    Can I use the Askar FMA180 Pro as a guide scope on a larger SCT?

    Absolutely. Its light weight of just 0.8kg and its Vixen-style dovetail, which can be attached to a larger scope's mounting rings or a finder shoe, make it an exceptional high-quality guide scope. The apochromatic optics ensure tight, round guide stars for precise tracking.

    What do I need to connect my astronomy camera to the FMA180 Pro?

    The FMA180 Pro terminates in standard M48x0.75 male threads. It is designed for a standard 55mm back focus, which is the same spacing required by most DSLRs with a T-ring and dedicated astronomy cameras when used with common filter wheels or off-axis guiders.

    Is the Askar FMA180 Pro a good choice for planetary imaging?

    No, this lens is a wide-field specialist. Its short 180mm focal length is designed to capture large swaths of the sky. For planetary imaging of targets like Jupiter or Saturn, you need a telescope with a much longer focal length (typically 2000mm or more) to achieve the necessary magnification.

  • Aperture Size 40mm
    Focal Length 180mm
    Focal Ratio f/4.5
    Objective Lens Sextuplet air-spaced APO with two ED elements
    Image Circle 44mm
    Back Focus 55mm
    Rear Thread M48×0.75 (with internal 2" filter thread)
    Total Length 167.5mm
    Total Weight 0.8kg (Including tube ring & dovetail plate)

    • FMA180 Pro OTA

      × 1

    • Instruction Manual

      × 1

  • Askar 1-Year Warranty