Four "normal" lenses for the 35mm format.
In photography the word normal lens is used for camera lenses that have a focal length which is roughly the diagonal of the image projected inside the camera. Camera lenses with a shorter focal length are called wide-angle lenses, those with a longer one telephoto lenses.
This gives a natural perspective.
| Film format |
Image dimensions |
Image diagonal |
Normal lens focal length |
| 9.5 mm Minox |
8 × 11 mm |
13.6 mm |
15 mm |
| APS C |
16.7 × 25.1 mm |
30.15 mm |
28 mm, 35 mm |
| 135 |
24 × 36 mm |
43.27 mm |
50 mm, 45 mm |
| 120/220, 6 × 4.5 (645) |
56 × 45 mm |
71.84 mm |
75 mm |
| 120/220, 6 × 6 |
56 × 56 mm |
79.20 mm |
80 mm |
| 120/220, 6 × 7 |
56 × 68 mm |
88.09 mm |
90 mm |
| 120/220, 6 × 9 |
56 × 84 mm |
100.96 mm |
105 mm |
| large format 4 × 5 sheet film |
96 × 120 mm (image area) |
153.67 mm |
150 mm |
| large format 8 × 10 sheet film |
194 × 245 mm (image area) |
312.51 mm |
300 mm |
- In Digital photography the situation is more complex. The sensor type diameter is not the sensor diameter:
- (*) refers to tv-tube diameters that were standards in the 50's. The normal lens focal length is roughly 2/3 of the TV tube diameter.
- (**) this is a mathematical calculation because most of the cameras have zoom lenses.
| Sensor type |
TV-tube diameter * |
Image dimensions |
Image diagonal |
- |
1/3.6" |
7.1 mm |
4.00 x 3.00 mm |
5.00 mm |
5 mm |
| 1/3.2" |
7.9 mm |
4.54 x 3.42 mm |
5.68 mm |
5.7 mm |
| 1/3" |
8.5 mm |
4.80 x 3.60 mm |
6.00 mm |
6 mm |
| 1/2.7" |
9.4 mm |
5.37 x 4.04 mm |
6.72 mm |
6.7 mm |
| 1/2.5" |
10.2 mm |
5.76 x 4.29 mm |
7.2 mm |
7 mm |
| 1/2" |
12.7 mm |
6.40 x 4.80 mm |
8.00 mm |
8 mm |
| 1/1.8" |
14.1 mm |
7.18 x 5.32 mm |
8.93 mm |
9 mm |
| 1/1.7" |
14.9 mm |
7.60 x 5.70 mm |
9.50 mm |
9.5 mm |
| 1/1.6" |
15.9 mm |
|
|
10.5 mm |
| 2/3" |
16.9 mm |
8.80 x 6.60 mm |
11.00 mm |
11 mm |
| 1" |
25.4 mm |
12.80 x 9.60 mm |
16.00 mm |
16 mm |
| 4/3" |
33.9 mm |
18.00 x 13.50 mm |
22.50 mm |
23 mm |
| (APS-C) 1/8" |
45.7 mm |
22.70 x 15.10 mm |
27.3 mm |
27 mm |
| DX |
n/a |
23.7 x 15.8 |
28.40 mm |
28 mm |
| FF (35 mm film) |
n/a |
36 x 24 mm |
43.30 mm |
50 mm |
| (4 x 5 cm) |
n/a |
49.0 x 36.7 mm |
61.22 mm |
|
| Film format |
Image dimensions |
Image diagonal |
Normal lens focal length |
| N-8 |
3.68 x 4.88 mm |
6.11 mm |
12 - 15 mm |
| Single - 8 (FUJI) |
4.22 x 6.24 mm |
7.53 mm |
15 - 17 mm |
| Super - 8 |
4.22 x 6.24 mm |
7.53 mm |
15 - 17 mm |
| 9.5 mm |
6.5 x 8.5 mm |
10.70 mm |
20 mm |
| 16 mm, magnetical sound |
7.49 x 10.26 mm |
12.70 mm |
25 mm |
| 16 mm, optical sound |
|
|
|
| 35 mm |
18.00 x 24.00 mm |
30.00 mm |
60 mm |
| 35 mm, sound |
16.03 x 22.05 mm |
40.53 mm |
|
| 65 mm |
|
|
|
| 70 mm |
52.6 x 23.0 mm |
57.41 mm |
|
See also
In Spanish: Objetivo normal para niños
