User manual ORION TELESCOPES & BINOCULARS SKYGLOW ULTRABLOCK

[. . . ] SkyGlowTM & UltraBlockTM Light-Pollution Filters #5660 #5659 #5658 #5654 #5657 #5656 1. 25" SkyGlow Broadband Filter 2" SkyGlow Broadband Filter SkyGlow Broadband Filter for Schmidt-Cassegrains 1. 25" UltraBlock Narrowband Filter 2" UltraBlock Narrowband Filter UltraBlock Narrowband Filter for Schmidt-Cassegrains The SkyGlow and UltraBlock Series of filters allows light from nebulas and other deep-space objects to pass through them while blocking light from street lights and other undesirable light sources. The SkyGlow Broadband Filter is useful in areas of moderate light pollution like nearby street lights. [. . . ] The filter provides the same threads as the rear cell of your Schmidt-Cassegrain, so you can continue to use any of your standard accessories as before. The Importance of Dark Adaptation Allowing your eyes to dark-adapt is the key to getting the most from your light pollution filter. Allow your eyes to dark-adapt for about 20-30 minutes 80 Transmission (%) before you use the filter. Once the pupil in your eye opens up, you'll be able to take full advantage of the benefits of the filter. Remember, the instant you glance at a bright object like a street lamp or bright flashlight bulb, your eyes lose their dark adaptation. You have to wait another 20-30 minutes for it to return. Locate the scope away from direct illumination by Transmission street lights. Set up in the "shadows" Characteristics of of buildings and other objects. Orion Broadband Skyglow Filter 60 20 Wavelength (nm) 0 100 Oxygen III 40 400 450 500 550 600 650 700 80 Transmission (%) Transmission Characteristics of Orion Narrowband UltraBlock Filter 60 Oxygen III 40 Hydro-gen Beta Hydrogen Alpha What You Will See These filters improve contrast between sky and object but will not actually make the object brighter. Expect a very dark sky background and a somewhat dimmer but highcontrast image. The filters perform best on emission objects like the Orion and Trifid nebulas in winter, and the Lagoon or Dumbbell nebulas in summer. Try these nebulas for your first use of the filter. [. . . ] If the glass surface accumulates oily dirt, use lens cleaning fluid and tissue as instructed in their package directions. 20 Wavelength (nm) 0 Hydro-gen Beta 400 450 500 550 600 650 Hydrogen Alpha 700 Common Light Pollution Emissions q q q vs q q qv q Mercury Street Lights, s Sodium Street Lights, v Ionized Oxygen Skyglow Customer Support (800) 676-1343 Email: support@telescope. com Providing Exceptional Consumer Optical Products Since 1975 Corporate Offices (831) 763-7000 P. O. Box 1815, Santa Cruz, CA 95061 IN 020 Rev B 07/02 [. . . ]