APERTURE TABLE 
1 
Corresponding Angle (2 u) for 
Limit of Resolving Power, in Lines to an Inch. 
Illuminating 
Power. 
m 
Pene- 
trating 
Power 
G) 
Numerical j 
Aperture 
(n sin u = a.) 
Air 
(n = 1-00). 
Water 
(n = 1-33). 
Homogeneous 
Immersion 
.(»= 1*52). 
White Light. 
(A. = 0-5269 ju., 
Line E.) 
Monochromatic 
(Bine) Light. 
(A = 0-4861 n, 
Line F.) 
Photography. 
(A = 0-4000 m, 
near Line h.) 
152 
,, 
180° 0' 
146,543 
158,845 
193,037 
2-310 
•658 | 
1-51 
.. 
166° 51' 
145,579 
157,800 
191,767 
2-280 
•662 i 
1-50 
.. 
161° 23' 
144,615 
156,755 
190,497 
2-250 
•667 
1-49 
„ 
157° 12' 
143,651 
155,710 
189,227 
2-220 
•671 
1-48 
153° 39' 
142,687 
154,665 
187,957 
2-190 
•676 
1-47 
.. 
150° 32' 
141,723 
153,620 
186,687 
2-161 
•680 
1-46 
.. 
147° 42' 
140,759 
152,575 
185,417 
2-132 
•685 
1-45 
„ 
145° 6' 
139,795 
151,530 
184,147 
2-103 
•690 . 
1*44 
142° 39' 
138,830 
150,485 
182,877 
2-074 
•694 
1-43 
. . 
140° 22' 
137,866 
149,440 
181,607 
2-045 
•694 
1*42 
138° 12' 
136,902 
148,395 
180,337 
2-016 
•709 
1-41 
136° 8' 
135,938 
147,350 
179,067 
1-988 
•709 
1 40 
134° 10' 
134,974 
146,305 
177,797 
1-960 
•714 t 
1-39 
132° 16' 
134,010 
145.260 
176,527 
1-932 
•719 
1-38 
130° 26' 
133,046 
144,215 
175,257 
1-904 
•725 - 
1-37 
, , 
128° 40' 
132,082 
143,170 
173,987 
1-877 
•729 
1-36 
126° 58' 
131,118 
142,125 
172,717 
1-850 
•735 
1-35 
125° 18' 
130,154 
141,080 
171,447 
1-823 
•741 
1-34 
, # 
123° 40' 
129,189 
140,035 
170,177 
1-796 
•746 
1-33 
180° 0' 
122° 6' 
128,225 
138,989 
168,907 
1-769 
•752 i 
1-32 
165° 56' 
120° 33' 
127,261 
137,944 
167,637 
1-742 
•758 
1-30 
155° 38' 
117° 35' 
125,333 
135,854 
165,097 
1*690 
•769 
1-28 
148° 42' 
114° 44' 
123,405 
133,764 
162,557 
1-638 
•781 :■*, 
1-26 
142° 39' 
111° 59' 
121,477 
131,674 
160,017 
1-588 
•794 
1-24 
137° 36' 
109° 20' 
119,548 
129,584 
157,477 
1-538 
•806 
1-22 
133° 4' 
106° 45' 
117,620 
127,494 
154,937 
1-488 
•820 1 
1-20 
, , 
128° 55' 
104° 15' 
115,692 
125,404 
152,397 
1-440 
•833 3 
118 
125° 3' 
101° 50' 
113,764 
123,314 
149,857 
1-392 
•847 l 
116 
121° 26' 
99° 29' 
111,835 
121,224 
147,317 
1-346 
•862 
114 
# 9 
118° 0' 
97° 11' 
109,907 
119,134 
144,777 
1-300 
•877 
1 12 
114° 44' 
94° 55' 
107,979 
117,044 
142,237 
1-254 
•893 9 
110 
# 0 
111° 36' 
92° 43' 
106,051 
114,954 
139,698 
1-210 
•909 £ 
108 
108° 36' 
90° 34' 
104,123 
112,864 
137,158 
1-166 
•926 
106 
105° 42' 
88° 27' 
102,195 
110,774 
134,618 
1-124 
•943 
104 
102° 53' 
86° 21' 
100,266 
108,684 
132,078 
1-082 
•962 » 
102 
0 # 
100° 10' 
84° 18' 
98,338 
106,593 
129,538 
1-040 
•980 i 
100 
180° 0' 
97° 31' 
82° 17' 
96,410 
104,503 
126,998 
1-000 
1-000 
0-98 
157° 2' 
94° 56' 
80° 17' 
94,482 
102,413 
124,458 
•960 
1-020 
0-96 
147° 29' 
92° 24' 
78° 20' 
92,554 
100,323 
121,918 
•922 
1-042 
0-94 
140° 6' 
89° 56' 
76° 24' 
90,625 
98,233 
119,378 
•884 
1-064 
0-92 
133° 51' 
87° 32' 
74° 30' 
88,697 
96,143 
116,838 
•846 
1-087 
0-90 
128° 19' 
85° 10' 
72° 36' 
86,769 
94,053 
114,298 
•810 
1*111 
0-88 
123° 17' 
82° 51' 
70° 44' 
84,841 
91,963 
111,758 
•774 
1-136 ? 
0-86 
118° 38' 
80° 34' 
68° 54' 
82,913 
89,873 
109,218 
•740 
1-163 
0-84 
114° 17' 
78° 20' 
67° 6' 
80,984 
87,783 
106,678 
•706 
1-190 
0 82 
110° 10' 
76° 8' 
65° 18' 
79,056 
85,693 
104,138 
•672 
1-220 
0-80 
106° 16' 
73° 58' 
63* 31' 
77,128 
83,603 
101,598 
•640 
1-250 
0-78 
102° 31' 
71° 49' 
61° 45' 
75,200 
81,513 
99,058 
•608 
1-282 
0-76 
98° 56' 
69° 42' 
60° 0' 
73,272 
79,423 
96,518 
•578 
1-316 
0*74 
95° 28' 
67° 37' 
58° 16' 
71,343 
77,333 
93,979 
•548 
1-351 
0-72 
92° 6' 
65° 32' 
56° 32' 
69,415 
75,242 
91,439 
•518 
1-389 * 
0-70 
88° 51' 
63° 31' 
54° 50' 
67,487 
73,152 
88,899 
•490 
1-429 
0-68 
85° 41' 
61° 30' 
53° 9' 
65,559 
71,062 
86,359 
•462 
1-471 
0-66 
82° 36' 
59° 30' 
51° 28' 
63,631 
68,972 
83,819 
•436 
1-515 
0-64 
79° 36' 
57° 31' 
49° 48' 
61,702 
66,882 
81,279 
•410 
1-562 : 
0-62 
76° 38' 
55° 34' 
48° 9' 
59,774 
64,792 
78,739 
•384 
1-613 
0-60 
73° 44' 
53° 38' 
46° 30' 
57,846 
62,702 
76,199 
•360 
1-667 
0-58 
70° 54' 
51° 42' 
44° 51' 
55,918 
60,612 
73,659 
•336 
1-724 
0*56 
68° 6' 
49° 48' 
43° 14' 
53,990 
58,522 
71,119 
•314 
1-786 
0-54 
65° 22' 
47° 54' 
41° 37 
52,061 
56,432 
68,579 
•292 
1-852 
0-52 
62° 40' 
46° 2' 
40° 0' 
50,133 
54,342 
66,039 
•270 
1-922 k 
0 50 
60° 0' 
44° 10' 
38° 24' 
48,205 
52,252 
63,499 
•250 
2-000 
0-45 
53° 30' 
39° 33' 
34° 27' 
43,385 
47,026 
57,149 
•203 
2-222 
0-40 
47° 9' 
35° 0' 
30° 31' 
38,564 
41,801 
50,799 
•160 
2-500 
0 35 
40° 58' 
30° 30' 
26° 38' 
33,744 
36,576 
44,449 
•123 
2-857 
030 
34° 56' 
26° 4' 
22° 46' 
28,923 
31,351 
38,099 
•090 
3-333 
0 25 
28° 58' 
21° 40' 
18° 56' 
24,103 
26,126 
31,749 
•063 
4-000 
020 
23° 4' 
17° 18' 
15° 7 
19,282 
20,901 
25,400 
•040 
5-000 
0 15 
17° 14' 
12° 58' 
11° 19' 
14,462 
15,676 
19,050 
•023 
6-667 
010 
11 ° 29' 
8° 38' 
7° 34' 
9,641 
10,450 
12,700 
•010 
10-000 1 
005 
5° 44' 
4° 18' 
3° 46' 
4,821 
5,225 
6,350 
•003 
20-000 
