Celestron Advanced VX 700 Maksutov Cassegrain Telescope Advanced VX - Page 28

This method can be done in daylight, thus eliminating the need to attempt in the dark. Although this method does NOT put you directly on the pole, it will limit the number of corrections you will make when tracking an object. It will also be accurate enough for short exposure prime focus planetary imaging (a couple of seconds) and short exposure piggyback astroimaging (a couple of minutes). Polar Align using the Hand Control The Advanced VX mount has a polar alignment function called "All-Star" Polar Alignment that will help you polar align your telescope for increased tracking precision and for astroimaging. This feature allows you to choose any bright alignment star to assist in accurately aligning your telescope's mount with the North Celestial Pole. Before using the Polar Align feature, the scope must first be roughly pointed towards north and should be aligned with three stars in the sky. See the "Latitude Scale" section for help with finding north and adjusting the mounts latitude. Once your telescope is aligned on two stars and at least one additional calibration star, slew the telescope to any bright star in its Named Star database list. For best results, choose a polar alignment star that is high in the sky and near the Meridian. Try to avoid stars that are close to the west/ east horizon, directly overhead or too near the celestial pole. Once completed, press the Align button and use the Up/ Down buttons on the hand controller to select Polar Align from the list. Align Mount - After performing a two star alignment with one calibration star and slewing your telescope to any bright star in the telescope's database, select the "Align Mount" option. The telescope will then slew away from and then back to the same star. 1. T he hand control will ask you to re-center the star in the finderscope and press ENTER. 2. T he hand control will ask you to accurately center the star in your eyepiece and press ALIGN. The telescope will then "sync" on this star and slew to the position that the star should be if it were accurately polar aligned. Note: For the most accurate alignment, it is best to use a reticle eyepiece or a high power eyepiece to precisely center the star in the field of view. 3. U se the mount's latitude and azimuth adjustments to place the star in the center of the eyepiece. Do not use the direction buttons on the hand control to position the star. Once the star is centered in the eyepiece, press ENTER; the polar axis should now be pointed towards the North Celestial Pole. Updating your Star Alignment After polar alignment, it is a good idea to check the pointing accuracy of the telescope to see how much it may have been affected by moving the mount. Since the polar alignment process requires you to "sync" the telescope on a bright star before you begin, it will be necessary to undo the sync before re-aligning. To undo the sync: • Press the Align button and use the Up/Down buttons on the hand controller to select Undo Sync from the list, and press Enter. The message Complete will display on the LCD. To re-align your telescope: 1. Slew the telescope to one of the original alignment stars or another bright star if the original alignment stars are no longer in a convenient location. Press the Align button and use the Up/Down buttons on the hand controller to select Alignment Stars from the list. 2. The hand control will ask you which of the original alignment stars you wish to replace. Use the Up/Down buttons to select the desired star and press Enter. 3. Once again, center the star in the finderscope and press Enter. 4. Center the star in the eyepiece and Press Align. 5. Repeat the process on a second alignment star. For additional all-sky pointing accuracy, it is a good idea to align on at least one additional calibration star located on the opposite side of the Meridian. To add calibration stars: 1. Slew the telescope to a bright star on the opposite side of the Meridian from your two alignment stars. 2. Press the Align button and use the Up/Down buttons on the hand controller to select Calib. Stars from the list, and press Enter. 3. Align the star in the finderscope and then in the eyepiece as you did with the alignment stars. Display Align - The user can now display the polar alignment error in the RA and DEC axes. These values show how close the mount is pointed at the celestial pole base on how accurately the user centered the alignment star with the hand control and with the mount adjustment. To display the alignment error: • Press the Align button and use the Up/Down buttons on the hand controller to select Display Align from the list, and press Enter. Long Exposure Prime Focus Photography This is the last form of celestial photography to be attempted after others have been mastered. It is intended primarily for deep sky objects, that is, objects outside our solar system including star clusters, nebulae, and galaxies. While it may seem that high magnification is required for these objects, just the opposite is true. Most of these objects cover large angular areas and fit nicely into the prime focus field of your telescope. The brightness of these objects, however, requires long exposure times and, as a result, are rather difficult. There are several techniques for this type of photography, and the one chosen will determine the standard accessories needed. The best method for long exposure deep sky astrophotography is with an optional off-axis guider. 28 I ENGLISH