Celestron CPC Deluxe 800 HD Computerized Telescope CPC Deluxe HD Manual - Page 31

The key factors for good CCD imaging are; exposure time, field-ofview, image size and pixel resolution. As the f-number goes down (or gets faster), the exposure times needed decreases, the field-of-viewincreases, but the image scale of the object gets smaller. What is the difference between f/2 and f/10? F/2 has 1/5 the focal length of f/10. That makes the exposure time needed about 25 times shorter than at f/10, the field of view 5 times larger and the object size 1/5 compared to that of f/10 (see Figure 8-8). Telescope Standard f/10 f/2 Model Configuration Configuration 8" 80" (2032 mm) 16" (406.4 mm) 9.25" 93" (2350 mm) 18.5" (470 mm) 11" 110" (2800 mm) 23.1" (587 mm) FIGURE 8-8 Auto Guiding The CPC has a designated auto guiding port for use with a CCD autoguider. Figure 8-9 may be useful when connecting the CCD camera cable to the CPC and calibrating the autoguider. Note that the four outputs are active-low with internal pull-ups and are capable of sinking 25 mA DC. 12 3456 1 = No Connect 2 = Ground 3 = +RA (Right) 4 = +DEC (Up) 5 = -DEC (Down) 6 = -RA (Left) FIGURE 8-9 Pin out diagram for Autoguider >> www.celestron.com 29