Howie Glatter Single Deep Red Beam 2" Holographic Laser Collimator - 650nm
- Single deep red beam operates at 650nm for night time use.
- The Howie Glatter Laser Collimator incorporates a solid state laser diode that does not fade or change with time and use.
- Factory-aligned to 15 arc-seconds providing 0.1 inch accuracy at a distance of 20 feet.
- The Howie Glatter Laser Collimator is shock resistant to keep its alignment - even when dropped.
- Includes 123A lithium battery, 1mm aperture stop, case, collimation rings and instructions.
This Laser Collimator is very different from other Collimators!
Howie Glatter Single Deep Red Beam Laser Collimator 2" 650nm
Howie Glatter produces some of the finest laser collimators available today. Howie Glatter's Laser Collimators are precision machined to fit your focuser perfectly. Even the Laser itself is tuned to a higher brightness than others. The Glatter holographic collimator has in addition to the laser, a removable transparent diffractive optic (the "hologram") that is placed in the path of the beam, just ahead of the laser. It diffracts light from the laser to project a diverging, symmetrical pattern around the beam, which is quite useful for centering optical elements and other procedures. The grid covers a wider angular range (21 degrees) than any other holographic collimator which allows direct centering of f/ 2.7 to f/ 35 optics. A rectilinear grid pattern gives the highest accuracy and sensitivity for centering circular optics of arbitrary size.
When it comes to lasers and collimation, one of the most trusted names in the business is guru Howie Glatter. His uncompromising quality and dedication to above average products, not only put his name above the rest - but in demand as the finest available on today's market. Usually a manufacturer doesn't take the time to explain to a customer exactly why their product excels over others - or why it performs better - but not Howie. Here's what he has to say about his new Howie Glatter Laser Collimator:
"The lasers in my collimators are class IIIa lasers (maximum beam power: 5 thousandths of a Watt), and are quite safe if used with reasonable precaution. Direct or mirror-reflected eye exposure to the laser beam should always be avoided! You must be careful when collimating to ensure that the beam does not enter anyone's eye. There is no problem in viewing the beam's impact directly on a surface as long as the surface produces a diffuse reflection. The beam impact may also be safely viewed on a mirror or lens surface if the reflected or transmitted beam is not directed towards your eye. Information from studies I have seen suggests that in order to induce permanent damage, a class IIIa laser beam must stay focused on the retina for a long time. It's unlikely for this to happen because the pupil is a very small target and because we have a blink and aversion reflex to bright light. However, all precautions should still be followed to avoid the beam entering anyone's eye! A badly miscollimated Newtonian or Cassegrain telescope may allow the beam to exit the front of the telescope, so when collimating, check first by pointing the telescope at a wall or screen to see if the beam is getting out. With unobstructed telescopes such as refractors, the beam will always exit the front of the telescope, so run a strip of masking tape across a diameter of the dew cap opening as a safety beam stop.
Inside the collimator is a solid-state laser diode, which emits an intense laser beam through a front aperture, exactly along the central axis of the cylindrical collimator body. The beam acts as a "reference line" from which alignments are made. For a laser collimator it is of supreme importance that the beam be aligned with the collimator's cylindrical axis, for if it is not, the resultant "alignment" of the telescope optics will be off-center and asymmetric, and the telescope will produce aberrated images.
When I started manufacturing laser collimators I realized that in order to produce consistent and accurate results they must be highly resistant to mechanical shock, so that internal laser alignment is maintained. I experimented with this aspect of collimator construction and developed a design which tremendously increased shock resistance. After aligning the laser within 15 arc seconds, I shock test each collimator by whacking it against a block of urethane plastic (urethane prevents marring), striking it at least a dozen times on three axis. I then recheck the laser alignment, and if it has not changed the collimator passes. I believe this is the most important difference setting my collimator apart from all others I know of. They will withstand a shock equivalent to dropping from eyepiece position, up the ladder on a big Dob, without alteration of laser alignment.
The most important specifications for a laser collimator are the accuracy and stability of the laser beam alignment to the cylindrical axis of the collimator body. Glatter's alignment tolerance is fifteen arc seconds for single beam mode, and one arc minute for the holographic mode. In order to ensure maintenance of this level of accuracy each of these collimators are engineered and then tested for resistance to shock.
The beam from all red diode lasers used in collimators is fuzzy-edged and elliptical in cross-section. When collimating, you sometimes must judge the location of the center of the spot by eye. To improve collimating precision, all of the collimators (except 532nm) are supplied with a removable accessory plastic aperture stop having a 1mm hole, which push-fits into the laser aperture. It produces a tiny, circular beam impact which allows more accurate alignment.
A single beam laser can be used to align the secondary mirror to the focuser axis. When the primary is aligned, however, a Barlow must be used to align the return beam-the single beam is not accurate enough. Howie Glatter can provide a Barlow attachment with the laser (order a laser with the self-Barlow attachment), you can use your own Barlow, or you can buy a Howie Glatter BLUG to fit your focuser (simply the easiest way to use a laser for primary collimation).
Optional holographic attachments screw into the laser aperture and have a white screen front surface. They contain an optical element that diffracts most of the laser light into a diverging symmetrical pattern around the central beam. The projected pattern is useful for centering optical elements by making it symmetrical with the edge of the optic.
Howie Glatter's collimators offer red with a choice of either 650 nanometer or 635nm wavelength. The two lasers have the same radiometric power output, but because the human eye's sensitivity to the shorter wavelength is greater, the 635nm. laser appears about two or three times brighter. The higher cost of 635nm laser diodes increases the collimator price, but it enables collimation in brighter ambient light. If you intend to collimate in early twilight, it is a good choice. In darkness, however, the 650nm laser is quite adequate. Because single beam collimators concentrate all the laser light in the central beam, the 650nm laser is quite adequate for them."
In order to achieve the best possible resolution and contrast, the optical elements of a telescope must be put into near-perfect alignment. Collimation is the adjustment of the position and orientation of the optical elements to achieve best performance. Laser collimation is a relatively new way to accurately and precisely collimate a telescope.
When practiced with accurate tools and correct techniques the various methods of collimation will converge to the same result, but laser collimation has several unique advantages. The laser collimator provides its own light source, so collimation can be readily accomplished or checked after dark without additional equipment. Unlike passive collimation tools, your eye position is not constrained by a peep-hole and cross hairs, and you don’t need to scrutinize elements at different distances simultaneously.
|Alignment Procedures||15 arc-seconds providing 0.1 inch accuracy at a distance of 20 feet|
|Power Requirements||3V CR123A Lithium Battery|