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Asking Price
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$210.00
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New
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Description:
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Now in stock!!!!
Howie Glatter 2" 635nm Holographic Collimator
Great Red Sot Astronomy Products
http://www.greatredspot.com/collimator.htm
Why settle for less than the best. Glatter collimators are each hand checked for accuracy that is unparalleled. Howie Glattter collimators are accurate to less tha .001 degreees... Try to get that type of accuracy from any other brand!
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. While several holographic patterns are available, the most versatile seems to be a 9 x 9 checkerboard grid of illuminated lines, which is standard with the Glatter holographic collimators. 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. A "scope", or concentric circle pattern can only be as accurate, if one of it's rings happens to be very near the optic's edge.
The diffractors are individually fit to their collimators for maximum alignment accuracy, so be careful not to accidentally or purposely switch diffractors from one device to another. If switched, maximum alignment accuracy in the holographic mode is likely to be lost. There are some collimating situations where the diffracted pattern is unnecessary and maximum power in the central beam is desired, so the diffractor of the Glatter collimator may be unscrewed from the laser aperture, converting the holographic collimator to single beam mode.
532, 635, or 650nm Wavelength? The larger the holographic pattern is, the more the laser's light is spread out, and so the pattern becomes less bright. Glatter offers the red holographic collimators with a choice of either 650 nanometer or 635nm wavelength. The 635nm. lasers appear about two or three times brighter than the 650nm, but these are more costly. The two lasers actually have the same radiometric power output, but the human eye's sensitivity to the shorter wavelength is greater. The difference would be in the level of ambient light that collimation can be done in.
The ultimate in pattern brightness is available with the Glatter 532nm green holographic laser collimator. It utilizes a 5 mw, 532nm laser that produces a high intensity green beam. This beam appears much brighter than the red ones in part because the human eye is most sensitive to light in this area of the spectrum. The 532nm beam makes collimation easy even in full daylight. The green collimator can also be used as a pointer for pointing out celestial objects to groups of people. This collimator has a body dimension of 4-1/2 inches in length. This incorporates two nosepiece diameters of 2" and 1-1/4" so that it can fit into either focuser.
Laser Accuracy and Stability 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 tested for resistance to shock. Glatter has designed the collimator bodies to withstand a shock equivalent to dropping the collimator from the eyepiece position on a tall Dobsonian telescope, without alteration of laser alignment. Most other laser collimators cannot withstand this kind of accident without loss of alignment.
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Keywords:
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Howie Glatter 2" 635nm Holographic Collimators
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