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PrimaLuceLab 7mm M48 Extension

PrimaLuceLab 7mm M48 Extension

by PrimaLuceLab
SKU PLL-PL3304807
CA$41.00 - CA$41.00
CA$41.00
CA$41.00 - CA$41.00
CA$41.00
Price Match Policy!
  • Provides a fixed 7mm optical path extension
  • Standard M48x0.75 male and female threads
  • Black anodized aluminum construction minimizes reflections
  • External knurled ring for enhanced grip
  • Stackable with other M48 extensions and spacers
1 in stock
Qualifies for FREE Shipping in Canada on orders over $500.
  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • PrimaLuceLab 7mm M48 Extension

    The PrimaLuceLab 7mm M48 Extension provides a fixed 7mm of spacing for any M48x0.75 threaded imaging train, essential for achieving the precise back focus required by field flatteners, focal reducers, and off-axis guiders.

    7mm M48 Threaded Spacer for Rigid Connections

    This extension is machined from metal and black anodized on all surfaces to prevent stray light reflections inside your imaging train. An external knurled band provides a secure grip, making it easy to tighten or loosen the adapter, even with gloves on during a cold night. The fixed 7mm length ensures perfect rigidity with no tilt or flex.

    Modular Spacing: Fine-Tune Back Focus in 0.5mm Steps

    Achieving perfect back focus is rarely a matter of a single spacer. This 7mm extension is a core component of a larger modular system. By stacking it with other M48 extensions or adding separately available 0.5mm and 1mm fine-tuning spacers, you can build the exact custom length your optical system demands with sub-millimeter precision.

  • What is the primary use for the PrimaLuceLab 7mm M48 Extension?

    The primary use is to add a precise 7mm of distance in an M48-threaded imaging train. This is critical for positioning a camera sensor at the exact back focus distance specified by an optical corrector like a field flattener or focal reducer, ensuring sharp stars across the entire frame.

    How does the PrimaLuceLab 7mm M48 Extension help achieve the 55mm back focus standard?

    Many correctors require a 55mm back focus. If your camera, filter wheel, and off-axis guider combine to a total distance of 48mm, this 7mm extension provides the final, rigid piece needed to reach the exact 55mm target without introducing any flex.

    Can I stack multiple PrimaLuceLab 7mm M48 Extensions together?

    Yes, these extensions are designed to be stackable. You can thread multiple extensions together to achieve longer distances, for example, two 7mm extensions would create a rigid 14mm spacer.

    What is the advantage of using a fixed 7mm extension over a variable spacer?

    A fixed extension like this 7mm M48 spacer offers superior rigidity. Variable spacers can sometimes introduce a small amount of tilt or flex into the optical train, which can be detrimental to image quality, especially with heavy cameras. A solid, fixed-length spacer eliminates this possibility.

    Will the PrimaLuceLab 7mm M48 Extension cause vignetting with my full-frame camera?

    No. The M48 (or "2-inch filter") thread standard has a large enough clear aperture to fully illuminate full-frame sensors (42mm image circle) without causing vignetting. This 7mm extension maintains that clear aperture throughout.

    How do I use the 7mm extension with other spacers to get a distance like 8.5mm?

    You can combine this 7mm extension with other available spacers. To achieve 8.5mm, you would thread together the 7mm extension, a 1mm spacer, and a 0.5mm spacer. This modularity allows you to create highly precise custom lengths.

  • Extension Length 7mm
    Thread Type M48x0.75
    Connections 1x Male, 1x Female
    Material Anodized Aluminum

    • PrimaLuceLab 7mm M48 Extension

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  • PrimaLuceLab 1-Year Warranty