Celestron CPC Deluxe 1100 HD Computerized Telescope - Manual (Page 31)

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The key factors for good CCD imaging are; exposure time, field-of-
view, image size and pixel resolution . As the f-number goes down (or
gets faster), the exposure times needed decreases, the field-of-view-
increases, 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).
FIGURE 8-8
T
elescope
s
Tandard f
/10
f
/2
M odel c onfiguraTion c onfiguraTion
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)
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 .
1 = No Connect
2 = Ground
3 = +RA (Right)
4 = +DEC (Up)
5 = -DEC (Down)
6 = -RA (Left)
1 2 3 4 5 6
FIGURE 8-9
Pin out diagram for Autoguider