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

The 635 nm wavelength laser in this Howie Glatter collimator appears about two to three times brighter to the human eye than a 650 nm laser of the same power. This makes the laser dot much easier to see when collimating in twilight or other conditions with ambient light.

The 1mm aperture stop is a push-fit cap that narrows the laser output. It is designed to solve two problems: it reduces the beam's brightness for more comfortable viewing and, more importantly, it transforms the naturally fuzzy-edged, elliptical laser dot into a tiny, perfectly circular diffraction pattern. This "star-like" pattern allows for much higher precision when centering the beam on your mirror's center mark.

For a Newtonian telescope, the process involves two main steps after inserting the Howie Glatter collimator into your 2" focuser: 1. Adjust the Secondary Mirror: Use the secondary mirror's adjustment screws to direct the red laser dot so it lands exactly in the center of your primary mirror's center-spot or ring. 2. Adjust the Primary Mirror: Go to the back of your telescope and use the primary mirror's collimation knobs. Adjust them until the return beam, reflected from the primary and back off the secondary, re-enters the aperture of the laser collimator itself. Once the beam disappears back into its source, your Newtonian is collimated.

Yes, but the process is different from a Newtonian. Since the only user adjustment on most SCTs is the secondary mirror's tilt, the best practice is to first achieve perfect collimation using a real star (a star test). Immediately after, replace the eyepiece with the Howie Glatter laser collimator (in single beam mode, without a diagonal). The position where the return beam hits the face of the collimator is now your reference point for perfect collimation. You can mark this spot to quickly return your SCT to that precise alignment anytime without needing another star test.

Yes, when used correctly. It is a Class IIIa laser with a maximum output of 5 mW. You must avoid any direct or mirror-reflected eye exposure to the beam. When collimating a Newtonian or Cassegrain, always first check if a misaligned mirror is causing the beam to exit the front of the telescope. For refractors, where the beam always exits the front, place a strip of masking tape over the dew shield opening to act as a beam stop.

Every Howie Glatter collimator is factory-aligned to a precision of 15 arc-seconds. To ensure this alignment holds, each unit is subjected to a shock test where it is struck repeatedly on three axes. The alignment is then re-verified. This process ensures the collimator will withstand normal handling and even accidental drops without losing its critical alignment.