Vixen POLARIE U Star Tracker, Инструкция по эксплуатации

Страница: 59 / 60

59
APPENDIX
Pinpoint star images at wide-field astrophotography mode subject to a polar alignment at an error of 2 degree
Note:
*1: The above focal lengths show actual focal lengths of your camera. It is not necessary to convert them to focal lengths in 35mm film format if APS�C, 3/4 or another format is utilized for your camera.
*2: The above exposure times are calculated on the assumption that the pixel size of an imaging device is 0.001mm. Allowable maximum exposure times will change according to the specifications of your camera
and lens. It is recommended you test your system to determine the best exposure time.
*3: If you use a 35mm film format camera, the above exposure times will be extended by three times and more due to bigger grains of film.
If this mode is selected, the POLARIE U follows stars at the same speed as the diurnal motion of the stars. It is suitable for capturing dark skies and faint
celestial objects. It is possible to avoid star trails, but the terrestrial objects are trailed in long exposure.
The table below shows allowable maximum shutter exposure times to hold pinpoint star images subject to a polar alignment at an error of 2 degrees
f=15mm f=20mm f=24mm f=28mm f=35mm f=50mm f=85mm f=100mm f=135mm f=200mm
0° (Celestial Equator)
6 min.
52 sec.
5 min.
09 sec.
4 min.
17 sec.
3 min.
41 sec.
2 min.
56 sec.
2 min.
03 sec.
1 min.
12 sec.
1 min.
01 sec.
45,8 sec 30,9 sec.
± 10°
6 min.
58 sec.
5 min.
14 sec.
4 min.
21 sec.
3 min.
55 sec.
2 min.
59 sec.
2 min.
0,5 sec.
1 min.
13 sec.
1 min.
02 sec.
46,5 sec 31,4 sec.
± 20°
7 min.
19 sec.
5 min.
29 sec.
4 min.
34 sec.
3 min.
55 sec.
3 min.
08 sec.
2 min.
11 sec.
1 min.
17 sec.
1 min.
05 sec.
48,7 sec. 32,9 sec.
± 30°
7 min.
56 sec.
5 min.
57 sec.
4 min.
57 sec.
4 min.
15 sec.
3 min.
24 sec.
2 min.
22 sec.
1 min.
24 sec.
1 min.
11 sec.
52,9 sec. 35,7 sec.
± 40°
8 min.
58 sec.
6 min.
43 sec.
5 min.
36 sec.
4 min.
48 sec.
3 min.
50 sec.
2 min.
41 sec.
1 min.
35 sec.
1 min.
20 sec.
59,8 sec. 40,3 sec.
± 50°
10 min.
41 sec. 8 min.
01 sec.
6 min.
41 sec.
5 min.
43 sec.
4 min.
35 sec.
3 min.
12 sec.
1 min.
53 sec.
1 min.
36 sec.
1 min.
11,3 sec.
48,1 sec.
± 60°
13 min.
45 sec. 10 min.
18 sec. 8 min.
35 sec.
7 min.
22 sec.
5 min.
53 sec.
4 min.
07 sec.
2 min.
25 sec.
2 min.
0.3 sec.
1 min.
31,6 sec.
1 min.
1,8 sec.
± 70°
20 min.
06 sec. 15 min.
04 sec. 12 min.
33 sec. 10 min.
46 sec. 8 min.
36 sec.
6 min.
01 sec.
3 min.
32 sec.
3 min.
00 sec.
2 min.
14 sec.
1 min.
30,4 sec.
± 80°
39 min.
17 sec. 29 min.
41 sec. 24 min.
44 sec. 21 min.
12 sec. 16 min.
58 sec. 11 min.
52 sec. 6 min.
59 sec.
5 min.
56 sec.
4 min.
23,9 sec.
2 min.
58,1 sec.
Separation from
the celestial equator
Focal length of
photographic
lens(mm)
*1