| 118 |
vrinda |
1 |
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
|
|
|
2 |
<html><head>
|
|
|
3 |
<meta content="text/html; charset=ISO-8859-1" http-equiv="content-type"><title>Focal Length</title>
|
|
|
4 |
|
|
|
5 |
</head>
|
|
|
6 |
<body>
|
|
|
7 |
<h1><a name="Focal_Length"></a>Focal Length</h1>
|
|
|
8 |
Focal
|
|
|
9 |
length is the measure of how strongly an optical system can converge or
|
|
|
10 |
diverge light – It is the distance over which rays can be brought to
|
|
|
11 |
focus. Shorter the focal length, higher the optical power and
|
|
|
12 |
magnification.<br>
|
|
|
13 |
<br>
|
|
|
14 |
Long focal length enables focusing on a distant object but narrows down
|
|
|
15 |
the angle of view.<br>
|
|
|
16 |
<br>
|
|
|
17 |
<img alt="" src="image/35mm.jpg" border="0">
|
|
|
18 |
<img alt="" src="image/100mm.jpg" border="0">
|
|
|
19 |
<img alt="" src="image/400mm.jpg" border="0">
|
|
|
20 |
<img alt="" src="image/1200mm.jpg" border="0"><br>
|
|
|
21 |
|
|
|
22 |
|
|
|
23 |
<span style="font-weight: bold;">35mm
|
|
|
24 |
|
|
|
25 |
|
|
|
26 |
|
|
|
27 |
|
|
|
28 |
|
|
|
29 |
|
|
|
30 |
|
|
|
31 |
|
|
|
32 |
100mm
|
|
|
33 |
|
|
|
34 |
|
|
|
35 |
|
|
|
36 |
|
|
|
37 |
|
|
|
38 |
|
|
|
39 |
|
|
|
40 |
|
|
|
41 |
|
|
|
42 |
400mm
|
|
|
43 |
|
|
|
44 |
|
|
|
45 |
|
|
|
46 |
|
|
|
47 |
|
|
|
48 |
|
|
|
49 |
|
|
|
50 |
1200mm</span><br>
|
|
|
51 |
<br>
|
|
|
52 |
</body></html>
|