| The following table shows common scope apertures
listed, both in inches and millimeters, with the associated Light
Grasp, Magnification limits and Limiting Visual Star Magnitudes.
| Aperture
in Inches |
Aperture
in Millimeters |
Light
Grasp |
Lowest
Magnification |
Highest
Magnification |
Limiting
Visual Magnitude assuming transparent dark skies |
| 0.98 |
25 |
13 |
4 |
40 |
9.7 |
| 1.26 |
32 |
21 |
5 |
51 |
10.2 |
| 1.57 |
40 |
33 |
7 |
63 |
10.7
|
| 1.65 |
42 |
36 |
7 |
66 |
10.8 |
| 1.97 |
50 |
51 |
8 |
79 |
11.2 |
| 2.36 |
60 |
73 |
10 |
95 |
11.6 |
| 2.76 |
70 |
100 |
12 |
111 |
11.9 |
| 2.99 |
76 |
118 |
13 |
120 |
12.1 |
| 3.15 |
80 |
130 |
13 |
126 |
12.2
|
| 3.35 |
85 |
147 |
14 |
134 |
12.3 |
| 3.5 |
88.9 |
161 |
15 |
140 |
12.4 |
| 3.54 |
90 |
165 |
15 |
142 |
12.5 |
| 3.94 |
100 |
204 |
17 |
158 |
12.7 |
| 3.98 |
101 |
208 |
17 |
160 |
12.7 |
| 4 |
101.6 |
210 |
17 |
161 |
12.7 |
| 4.02 |
102 |
212 |
17 |
161 |
12.7 |
| 4.13 |
105 |
225 |
18 |
166 |
12.8 |
| 4.33 |
110 |
247 |
18 |
174 |
12.9 |
| 4.49 |
114 |
265 |
19 |
180 |
13.0 |
| 4.5 |
114.3 |
266 |
19 |
181 |
13.0 |
| 4.72 |
120 |
294 |
20 |
190 |
13.1 |
| 4.92 |
125
|
319 |
21 |
198 |
13.2 |
| 5 |
127 |
329 |
21 |
201 |
13.2 |
| 5.12 |
130 |
345 |
22 |
205 |
13.3 |
| 5.91 |
150 |
459 |
25 |
237 |
13.6 |
| 6 |
152.4 |
474 |
25 |
241 |
13.6 |
| 7 |
177.8 |
645 |
30 |
281 |
13.9 |
| 7.87 |
200 |
816 |
33 |
316 |
14.2 |
| 8 |
203.2 |
842 |
34 |
321 |
14.2 |
| 9.25 |
234.95 |
1126 |
39 |
371 |
14.6 |
| 10 |
254 |
1315
|
42 |
401 |
14.7 |
| 11 |
279.4 |
1592 |
47 |
441 |
14.9 |
| 12 |
304.8 |
1894 |
51 |
482 |
15.1 |
| 12.5
|
317.5 |
2055 |
53 |
502 |
15.2 |
| 14 |
355.6 |
2578 |
59 |
562 |
15.5 |
| 16 |
406.4 |
3368 |
68 |
642 |
15.7 |
| 20
|
508 |
5262 |
85 |
803 |
16.2 |
|
|