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David Astro M48 Extension Tube - 5mm

by David Astro
SKU DAV-M48-EXT-5
Sold out
CA$15.00 - CA$15.00
CA$15.00
CA$15.00 - CA$15.00
CA$15.00
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  • Adds 5mm of spacing to an imaging train
  • M48 thread
  • Helps set the back focus of a flattener, reducer or corrector
  • Can be stacked with other M48 extension tubes
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  • Description
  • FAQ
  • Specifications
  • In the Box

  • David Astro M48 Extension Tube - 5mm

    The David Astro M48 Extension Tube - 5mm adds a fixed 5mm of length to an imaging train that uses the M48 thread. Use it to place your camera sensor at the distance a field flattener, reducer or corrector needs.

    Fixed 5mm Spacing for Correct Back Focus

    Field flatteners, reducers and coma correctors give their sharpest stars only when the camera sensor sits at a set distance behind them, the back focus. This tube closes a 5mm gap in that distance. Several tubes can be stacked to build the total spacing your setup needs.

    Why M48

    The M48 thread is wider than the M42 T-thread. With larger camera sensors, an M48 imaging train lowers the risk of vignetting (darkened corners) that a narrower M42 path can cause. The thread pitch of this tube is not stated in our product data. Contact us before ordering and we will confirm it for you.

  • What is the David Astro M48 Extension Tube - 5mm used for?

    It adds a fixed 5mm of spacing between the components of an imaging train, most often to reach the back focus distance required by a field flattener, reducer or corrector.

    Can I stack the David Astro M48 Extension Tube - 5mm with other M48 extension tubes?

    Yes. Extension tubes are made to be combined. Add this 5mm tube to other M48 tubes to build the total spacing you need.

    What is the thread pitch of the David Astro M48 Extension Tube - 5mm?

    The pitch of the M48 thread is not stated in our product data. Contact us before ordering and we will confirm it for you.

    How do I know if I need a 5mm extension tube?

    Add up the spacing of your camera and adapters and compare it with the back focus your corrector requires. If the gap is 5mm, or 5mm is one of the pieces that makes up the gap, this tube fills it.

    What happens if the back focus spacing is wrong?

    Correctors are designed to work at one distance from the sensor. If the spacing is off, stars near the corners of the image become elongated or distorted.

    Can I use the M48 tube with M42 (T2) accessories?

    Not directly. M48 and M42 are different thread diameters, so an M48 to M42 adapter is needed to join the two.

  • Brand David Astro
    SKU DAV-M48-EXT-5
    Thread M48
    Length 5mm

    • David Astro M48 Extension Tube - 5mm

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