Photron Ritchey-Chrétien Optical Tube Assembly INSTRUCTION MANUAL WARNING! NEVER USE A TELESCOPE TO LOOK AT THE SUN! Looking at or near the Sun will cause instant and irreversible damage to your eye. Children should always have adult supervision while observing iOptron Corporation | 6E Gill Street | Woburn, MA 01801 | www.iOptron.
Losmandy-style one. Welcome to a new world of adventure! The iOptron® Photron Ritchey-Chrétien design telescopes feature low thermal expansion quartz primary and secondary mirrors with ninety-nine percent reflective dietetic coatings. The RC optical design delivers coma, spherical and chromatic aberration free results, perfect for color or monochrome imaging. A fixed position primary mirror eliminates image shift that occurs from focusing with other telescope designs.
Stabilizing track Drawtube lock knob Drawtube lock knob Drawtube tension adjustment knob Attachment collar The 8" RC has a 2" linear-bearing Crayford focuser, which has a stabilizing track on the underside of the drawtube that provides extra rigidity for carrying heavy payloads. The tension adjustment knob is on the underside of the focuser while the larger locking knob is on top.
final focusing for astrophotographic framing by slightly loosening the focuser attachment collar (turning it counterclockwise), then rotating the focuser to the desired position, then retightening the collar. between the optical tube and the focuser to take up unneeded backfocus. If the focuser drawtube is fully extended and you are still unable to achieve focus you will need to install one or more extension rings.
more than one rings depends on your equipment. It may be useful to experiment with different combinations during the day before heading out into the field. Choose a target over half a mile away to ensure you are simulating infinity focus. The goal is to reach focus with as little extension of the focuser drawtube as possible, to avoid drawtube flexure.
included with the 10" RC. The cable from the battery holder plugs into the DC power jack on the rear cell. The fans can also be powered by other 12V DC power supply, such as a iOptron PowerWeight (#8128) or other portable battery. The DC plug is 5mm/2.1mm, center positive. We recommend turning them off while actively observing or imaging to avoid any effect on the view from vibration or blowing air. steps.
should be reasonably tight so the secondary mirror won’t shift while the scope is in use. Secondary Mirror Adjustment If the view looks something like the following figure with the dot of the collimation eyepiece NOT centered in the secondary center ring, the secondary mirror needs be adjusted. Always start by loosening one screw. Adjust the screws only very slightly—by no more than 1/8 turn at a time, and one screw at a time before checking the view through the Cheshire again to see how things changed.
Insert an eyepiece directly into the focuser drawtube by using the 1.25” ring adapter. The eyepiece should provide moderate to high magnification. DO NOT use a star diagonal. An ideal target is a star close to the zenith (straight overhead) rather than at the horizon to minimize atmospheric distortions. Using Polaris as your target star can be helpful as minimal drift adjustments will be required. Center the star in the field of view.
Specifications: Photron RC6 RC8 RC10 Optical design Ritchey‐Chretien Ritchey‐Chretien Ritchey‐Chretien optical type Hyperbolic Hyperbolic Hyperbolic Optical diameter 150mm 200mm 250mm Focal length 1370mm 1624mm 2000mm Focal ratio f/9 f/8 f/8 Resolving power 0.76 arcsec 0.58 arcsec 0.46 arcsec Limiting stellar magnitude 13.6 14.2 14.
