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Howie Glatter Single 635nm Red Beam Laser Collimator - 1.25"/2"
Howie Glatter Single 635nm Red Beam Laser Collimator - 1.25"/2"

Howie Glatter Single 635nm Red Beam Laser Collimator - 1.25"/2"

by Howie Glatter
SKU SI-LC2125-635
$320.00 USD - $320.00 USD
$320.00 USD
$320.00 USD - $320.00 USD
$320.00 USD
Price Match Policy!
  • 635nm single red laser beam
  • Fits both 1.25" and 2" eyepiece holders
  • Factory-aligned to 15 arc-seconds
  • Class IIIa laser with maximum 5 mW output
  • Includes 1mm aperture stop for a high-precision beam
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Howie Glatter Single 635nm Red Beam Laser Collimator - 1.25"/2"

    The Howie Glatter Single 635nm Red Beam Laser Collimator establishes an exacting optical axis reference, factory-aligned to within 15 arc-seconds for professional-grade collimation. This Class IIIa laser is listed for 1.25" and 2" eyepiece holders, providing a solid-state 635 nm beam that appears two to three times brighter to the human eye than standard 650nm lasers. Every unit is subjected to rigorous shock testing on three axes to ensure its alignment holds true, delivering a consistent reference line for collimating your Newtonian, refractor, or Cassegrain telescope.

    A 15 Arc-Second Alignment Reference

    At the core of this tool is a solid-state laser diode precisely aligned to the collimator's cylindrical body. This alignment is certified to within 15 arc-seconds, which translates to a deviation of just 0.1 inches at a distance of 20 feet. When you insert the collimator into your focuser, it projects a beam that perfectly represents the focuser's central axis, serving as the definitive reference line for aligning all other optical components.

    Shock-Tested Build for Unwavering Accuracy

    A laser collimator is only useful if it holds its alignment. To guarantee this, each Howie Glatter collimator is struck at least a dozen times on three separate axes against a urethane block and its alignment is re-verified. This process ensures the collimator can withstand the inevitable bumps and drops of field use without losing its critical 15 arc-second precision, setting it apart from less robust designs.

    Pinpoint Accuracy with the 1mm Aperture Stop

    The raw beam from any diode laser has a fuzzy, elliptical profile, making it difficult to judge its precise center. This collimator includes a push-fit 1mm aperture stop that solves this problem. When installed, it constricts the beam, producing a tiny, circular point of light that allows for far more accurate centering on your primary mirror's center mark. At a distance, this focused beam creates a star-like diffraction pattern, with a central dot and surrounding rings that further aid in achieving perfect alignment.

    Universal 1.25"/2" Fit for All Telescope Types

    This collimator fits both 1.25" and 2" eyepiece holders, so one tool can serve telescopes with either size, whether you are performing a full Newtonian collimation, checking refractor objective tilt, or aligning the secondary on a Cassegrain. The body also features a 3/8-32 thread for attaching optional accessories like Howie Glatter's holographic attachments.

    Choosing the 635nm Model Over the 650nm

    While both the 650nm and 635nm Howie Glatter lasers have the same 5 mW maximum power output, their visibility is very different. The human eye is more sensitive to the 635nm wavelength, making it appear two to three times brighter than the 650nm version.

    • Choose this 635nm model if: You plan to collimate in early twilight or other brighter ambient light conditions where a standard laser can be difficult to see.
    • Consider the 650nm model if: You primarily collimate in full darkness, where the brightness of the 635nm beam is less critical and the standard model is perfectly adequate.

  • How does the Howie Glatter 635nm collimator maintain its alignment so well?

    Each collimator undergoes a rigorous shock-testing procedure at the factory. After its initial alignment to 15 arc-seconds, the unit is struck at least a dozen times on three different axes. The alignment is then rechecked to ensure it has not shifted, and the collimators withstand a shock equivalent to a drop from eyepiece position up the ladder on a big Dob.

    What is the purpose of the included 1mm aperture stop?

    The aperture stop is used to increase collimation accuracy. It push-fits into the laser aperture and transforms the standard fuzzy, elliptical laser dot into a tiny, circular beam. This makes it much easier to judge the exact center of the beam on your primary mirror's center marking. The resulting beam also creates a diffraction pattern that can be used for even finer centering adjustments.

    Can I use the Howie Glatter single-beam laser to collimate my Newtonian without a center spot on the primary?

    No, for a single-beam laser collimator, a center spot or ring on the primary mirror is essential. The process requires you to adjust the secondary mirror until the laser beam hits the exact center of the primary. Without a reference mark, it is impossible to judge this alignment accurately by eye. A holographic attachment (sold separately) allows secondary adjustment without a center dot, by making the pattern symmetrical at the edge of the primary.

    How do I safely use this Howie Glatter laser collimator with my refractor?

    Safety is critical. The laser beam will always exit the front of a refractor. Before you begin, place a strip of masking tape across the opening of the dew shield to act as a beam stop. This prevents the Class IIIa laser beam from exiting the telescope. Always avoid direct or mirror-reflected eye exposure to the beam.

    When should I choose the 635nm Howie Glatter collimator over the 650nm version?

    Choose this 635nm model if you often collimate in brighter conditions, such as during twilight. Its beam appears two to three times brighter to the eye, making it much easier to see. For collimation in complete darkness, the standard 650nm laser is sufficient and perfectly adequate for single-beam use.

  • Model LC2125-635
    Wavelength 635 nm (red)
    Beam Single beam
    Fits 1.25" and 2" eyepiece holders
    Laser Class IIIa (maximum output 5 mW)
    Alignment Factory-aligned to 15 arc-seconds (0.1 in at 20 ft)
    Laser Source Solid-state laser diode
    Shock Testing Each collimator struck at least a dozen times on three axes, alignment rechecked
    Battery 123A lithium
    Attachment Thread 3/8-32 (current version, identified by a visible ring)
    Optional Accessories Holographic attachments (square grid, concentric circle, cross hair), Barlow attachment, Variable Laser Brightness cap
    Use Newtonian, refractor and Cassegrain collimation

    • Howie Glatter 635 nm single-beam 1.25/2" laser collimator

      × 1

    • 123A lithium battery

      × 1

    • 1 mm aperture stop

      × 1

    • Protective case

      × 1

  • Howie Glatter Warranty