Howie Glatter Single 650nm Red Beam Laser Collimator - 1.25"

A 15 Arc-Second Reference Beam, Shock-Tested for Alignment

The core of any laser collimator is the certainty that its beam is perfectly parallel to its body. Each Howie Glatter collimator is factory-aligned to a tolerance of 15 arc-seconds and then subjected to a rigorous shock test, being struck at least a dozen times on three axes to simulate drops and impacts. The alignment is then re-checked to ensure it holds, so the reference beam you use for collimation stays true.

This durability means the collimator can withstand a drop from the focuser of a large Dobsonian without losing its critical alignment. It’s a tool built not just for precision, but for repeatable precision under real-world observing conditions.

650nm Beam with 1mm Aperture Stop for Pinpoint Accuracy

This model uses a 650nm red laser, which is perfectly adequate for collimation in dark conditions. To refine the standard fuzzy-edged beam of a diode laser, a removable 1mm aperture stop is included. When pushed into the laser aperture, it transforms the beam into a tiny, circular point surrounded by faint diffraction rings.

This pattern makes it significantly easier to judge the exact center of the beam's impact on your primary mirror's center mark or on the face of the collimator itself. The surrounding rings help center the beam very accurately, and the small stop increases precision when locating the return spot on the collimator face.

Collimation for Newtonians, Refractors, and Cassegrains

The single-beam laser provides the essential reference line needed for the fundamental collimation steps of any telescope design. The process always begins by establishing the eyepiece axis as the master reference, from which all other components are aligned.

• For Newtonians: The laser is used to adjust the secondary mirror to aim the beam at the exact center of the primary, and then to adjust the primary mirror to return the beam precisely back into the collimator's aperture.
• For Refractors: After ensuring the beam is centered on the objective lens, the laser's reflection from the rear lens surface is used to adjust the objective's tilt until the return beam is centered on the collimator.
• For Cassegrains: A single-beam collimator allows the back-axis and secondary alignment; a holographic attachment is needed for primary and corrector alignment. This model can also be used to record a star-collimated secondary position on an SCT for later reproduction.

Howie Glatter 650nm vs. 635nm: Choosing the Right Wavelength

Howie Glatter offers red lasers in two wavelengths, 650nm and 635nm, both with the same radiometric power output. The primary difference is how the human eye perceives their brightness. The 635nm laser appears two to three times brighter to the eye, making it a better choice if you frequently collimate in twilight or brighter ambient light.

For most users, the 650nm laser is entirely sufficient. Because a single-beam collimator concentrates all its light into one spot, the 650nm laser is quite adequate in darkness. The 635nm diode costs more, which is reflected in its price.