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Section 4 - Camera Hardware
Page 30
C8, 8" f/10
LX200, 10" f/3
6
14" f/11
Camera
Field of
View
(arcmins)
Pixel
Size
(arcsecs)
Field of
View
(arcmins)
Pixel
Size
(arcsecs)
Field of
View
(arcmins)
Pixel
Size
(arcsecs)
Tracking
CCD
4.2x4.2 1.3x1.5 11.7x11.7 3.7x4.3 2.3x2.3 0.7x0.8
ST-5C 5.4x4.1 1.0x1.0 14.4x10.8 2.7x2.7 2.8x2.1 0.5x0.5
ST-237 8.0x6.0 0.75x0.75 21.6x16.2 2.0x2.0 4.0x3.0 0.38x0.38
STV 8.0x5.0 1.5x1.5 21.6x13.5 4.0x4.0 4.0x2.5 0.75x0.75
ST-6 14.6x11.1 2.3x2.7 38.9x29.5 6.2x7.3 7.6x5.7 1.2x1.4
ST-7E 11.9x7.9 0.9x0.9 31.2x20.8 2.4x2.4 6.1x4.1 0.5x0.5
ST-8E 23.8x15.8 0.9x0.9 62.4x41.6 2.4x2.4 12.2x8.2 0.5x0.5
ST-9E 17.6x17.6 2.0x2.0 46.2x46.2 5.3x5.3 9.1x9.1 1.1x1.1
ST-10E 25.1x16.9 0.7x0.7 67.0x45.2 1.8x1.8 13.0x8.8 0.36x0.36
ST-1001E 41.6x41.6 2.4x2.4 111x111 6.5x6.5 21.6x21.6 1.27x1.27
Table 4.4 - Field of View
Object Size
Focal Length to fill
Tracking CCD
Focal Length to fill
ST-7E
Moon 0.5° 275mm =
11 inches
760mm =
30 inches
Jupiter 40 arcseconds 13000mm =
510 inches
34000mm =
1350 inches
M51-Whirlpool
Galaxy
8 x 5
arcminutes
1040mm =
41 inches
3700mm =
145 inches
M27-Dumbell
Nebula
8.5 x 5.5
arcminutes
" "
M57-Ring Nebula 1.3 x 1
arcminutes
6400mm =
250 inches
23000mm =
900 inches
Table 4.5 - Focal Length Required
From these numbers you can deduce that the popular C8, an 8" f/10 telescope will nicely frame
many popular objects with the ST-7E whereas a much shorter system (f/3, perhaps achieved
with a focal reducer) will frame the same objects for the tracking CCD. Another point to bear
in mind is that, except for planetary images, you'll rarely take images where the pixel size in
seconds of arc is down near the seeing limit. Most objects are relatively large, where the field
of view is more important than whether the individual pixels are less than half the seeing.
4.6 Connecting the older model CFW-6 filter wheel to the Camera
The SBIG CFW-6 filter wheel can be connected to the camera using the relay port
adapter provided with the camera. The adapter plugs into the 9 Pin connector on the
6
f/6.3 with the Meade star digonal focal reducer.