{"product_id":"howie-glatter-holographic-attachment-for-laser-collimator-concentric-circle-pattern","title":"Howie Glatter  Holographic Attachment for Laser Collimator - Concentric Circle Pattern","description":"\u003cdiv class=\"text-justify\" style=\"BACKGROUND-COLOR: none\"\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cdiv\u003e \u003cdiv class=\"note\"\u003e \u003cp\u003ePurtroppo, questa descrizione non è stato tradotto in italiano, in modo da trovare a questo punto una descrizione inglese.\u003c\/p\u003e\n\u003c\/div\u003e \u003cp\u003e \u003c\/p\u003e\n\u003cp\u003eOptional 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. \u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eThree different patterns are available:\u003c\/b\u003e\u003c\/p\u003e \u003cul\u003e \u003cli\u003eA 10 x 10 line square grid pattern is supplied as standard unless otherwise requested because it is the widest pattern. It spreads 21 degrees which allows centering of optics as fast as f\/ 2.7. This pattern is recommended for general use because it can be used with the fastest telescopes likely to be encountered. \u003c\/li\u003e\n\u003cli\u003eA nine-concentric circle pattern is available that spans 10 degrees and will reach to the edge of f\/ 5.7 optics. This pattern is recommended for scopes around this focal ratio or slower. Because the laser light is spread over a smaller area it is brighter than the square grid pattern, and this makes it particularly useful with Cassegrain scopes, where the pattern impact is sometimes scrutinized on the mirror surfaces. The projected pattern is seen only by light that is scattered from dust, dirt, or optical roughness, so a brighter pattern is better, especially if the mirrors are very clean. \u003c\/li\u003e\n\u003cli\u003eA cross-hair and circle “scope” pattern is available that spans 10 degrees. It has utility for non-Barlowed , conventional Newtonian primary collimation, where the primary is adjusted to return the reflected central laser beam back into the laser aperture of the collimator. The cross-hair intersection makes it easier to see when the return beam is centered on the collimator face.\u003c\/li\u003e\n\u003c\/ul\u003e \u003cp\u003e\u003c\/p\u003e\n\u003c\/div\u003e \u003cp\u003e\u003c\/p\u003e \u003cdiv class=\"important\"\u003e \u003ch2 class=\"hdl-02 mar-0\"\u003eCommento del nostro esperto:\u003c\/h2\u003e \u003cp\u003e \u003c\/p\u003e\n\u003cdiv\u003e \u003cdiv class=\"note\"\u003e \u003cp\u003ePurtroppo, questa descrizione non è stato tradotto in italiano, in modo da trovare a questo punto una descrizione inglese.\u003c\/p\u003e\n\u003c\/div\u003e \u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cb\u003eThis is the new version (\"NV\") with coarse thread.\u003c\/b\u003e The attachment fits all Howie Glatter\/Starlight Instruments laser collimators, which also have a new thread (\"NV\" in the item number). If you own an \u003cu\u003eolder\u003c\/u\u003e version of the laser (before 2020), please contact us prior to your order! \u003c\/p\u003e\n\u003cp\u003e(Jan Ströher)\u003c\/p\u003e\n\u003c\/div\u003e \u003cp\u003e\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Howie Glatter","offers":[{"title":"Default Title","offer_id":51120675029208,"sku":"45972","price":172.99,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0766\/0722\/6072\/files\/6a0915f01143ab6b2afe80ff94c737f1.jpg?v=1764069400","url":"https:\/\/www.giordanoastronomia.it\/products\/howie-glatter-holographic-attachment-for-laser-collimator-concentric-circle-pattern","provider":"Giordano Astronomia","version":"1.0","type":"link"}