APERTURE TABLE 
Numerical 
Aperture. 
( n sin u = a.) 
Corresponding Angle (2 u) for 
Limit of Resolving Power, in Lines to an Inch.l 
1 Pern- 
* trating 
Power. 
0 
Air 
(« = 1-00). 
Water 
(n = 1-33). 
Homogeneous 
Immersion 
(« =1-52). 
White Light. 
(A = 0*5269 fj., 
Line E.) 
Monochromatic 
(Blue) Light. 
(A =0-4861 ix. 
Line F.) 
1 Photography. 
(A = 0-4000 /u., 
Near Line h .) 
illuminating 
Power. 
(«*-) 
1*52 
180° 0' 
146,543 
158,845 
193,037 
2 
310 
•658 
1*51 
•• 
166° 51' 
145,579 
157,800 
191,767 
2 
280 
*662 
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 
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 
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*20 
128° 55' 
104° 15' 
115,692 
125,404 
152,397 
1 
440 
•8:’. 3 
1*18 
125° 3' 
101° 50' 
113,764 
123,314 
149,857 
1 
392 
•847 
1*16 
121° 26' 
99° 29' 
111,835 
121,224 
147,317 
1 
346 
•862 
1*14 
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 
1*10 
111° 36' 
92° 43' 
106,051 
114,954 
139,698 
1 
210 
•909 
1*08 
108° 36' 
90° 34' 
104,123 
112,864 
137,158 
1 
166 
•926 
1*06 
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 
1 02 
100° 10' 
84° 18' 
98,338 
106,593 
129,538 
1 
040 
•980 
1*00 
180° 0' 
97° 31' 
82° 17' 
96,410 
104,503 
126,998 
1 
000 
1-000 
0*98 
157° 2' 
94° 56' 
8o° 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 
98,223 
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 
1-923 
0*50 
60° O' 
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 
0*30 
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 
0*20 
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 
0*10 
11° 29' 
8° 38' 
7° 34' 
9,641 
10,450 
12,700 
010 
10 000 
005 
5° 44' 
4° 18' 
3° 46' 
4,821 
5,252 
6,350 
003 
20-000 
