APERTURE TABLE. 
Numerical 
Aperture. 
Corresponding 
Angle (2 w) for 
Limit of Resolving Power, in Lines to an Inch 
Pene- 
Air 
Water 
Homogeneoui 
White Light. 
Monochromati( 
(Blue) Light. 
3 
Photography. 
Illuminatinj 
Power. 
g trating 
Power. 
/^\ 
(n Bin u = a.) 
O 
o 
II 
(n = 
1*33). 
(n = 1*52). 
(\ = 0-5269 iL, 
Line E.) 
, (A = 0-4861 /Lt, 
Line F.) 
, (A = 0-4000 /a, 
near Line A.) 
( a 2 .) 
Q 
1*52 
. . 
180 ° 0 ' 
146,543 
158,845 
193,037 
2-310 
•658 
1*61 
.. 
166 ° 51 ' 
145,579 
157,800 
191,767 
2-280 
•662 
1*60 
161 ° 23 ' 
144,615 
156,755 
190,497 
2-250 
•667 
1 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 
•699 
1-42 
.. 
138 ° 12 ' 
136,902 
148,395 
180,337 
2-016 
•704 
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 
.. 
136 ° 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 
•833 
118 
125 ° 
3 ' 
101 ° 50 ' 
113,764 
123,314 
149,857 
1-392 
•847 
116 
121 ° 
26 ' 
99 ° 29 ' 
111,835 
121,224 
147,317 
1-346 
•862 
114 
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 
110 
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 
100 ° 
10 ' 
84 ° 18 ' 
98,338 
106,593 
129,538 
1-040 
•980 
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 i 
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 A 
0-70 
88 ° 51 ' 
63 ° 
31 ' 
54 ° 50 ' 
67,487 
73,152 
88,899 
-490 
1-429 1 
0-68 
85 ° 41 ' 
61 ° 
30 ' 
53 ° 9 ' 
65,559 
71,062 
86,359 
-462 
1-471 j 
0-66 
82 ° 36 ' 
59 ° 
30 ' 
51 ° 28 ' 
63,631 
68,972 
83,819 
-436 
1-515 4 
0-64 
79 ° 36 ' 
57 ° 
31 ' 
49 ° 48 ' 
61,702 
66,882 
81,279 
-410 
1-562 1 
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 1 
0-58 
70 ° 54 ' 
51 ° 
42 ' 
44 ° 51 ' 
55,918 
60,612 
73,659 
-336 
1-724 
0-66 
68 ° 6 ' 
49 ° 
48 ' 
43 ° 14 ' 
53,990 
58,522 
71,119 
-314 
1-786 i 
0*54 
65 ° 22 ' 
47 ° 
54 ' 
41 ° 37 ' 
52,061 
56,432 
68,579 
•292 
1-852 i 
0-52 
62 ° 40 ' 
46 ° 
2 ' 
40 ° 0 ' 
50,133 
54,342 
66,039 
•270 
1-923 ^ 
0-60 
60 ° 0 ' 
44 ° 
10 ' 
38 ° 24 ' 
48,205 
52,252 
63,499 
•250 
2-000 1 
0-45 
53 ° 30 ' 
39 ° 
33 ' 
34 ° 27 ' 
43,385 
47,026 
57,149 
•203 
2-222 1 
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 ' 
33,741 
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 i 
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 
. 0-000 4 
005 
5 ° 44 ' 
4 ° 
18 ' 
3 ° 46 ' 
4,821 
5,225 
6,350 
•003 5 
! 0-000 1 
