镜头焦距换算表
| 35mm | 6x6cm | 6x7cm | 6x9cm | 6x12cm | 4x5英寸 | 5x7英寸 | 8x10英寸 | |
| 对角线长 | 43 | 80 | 90 | 100 | 125 | 150 | 210 | 300 |
| 焦 距 |
18 | 33 | 37 | 42 | 53 | 65 | 90 | 130 |
| 21 | 39 | 43 | 48 | 60 | 75 | 105 | 150 | |
| 22 | 41 | 45 | 52 | 65 | 80 | 110 | 160 | |
| 25 | 46 | 50 | 58 | 75 | 90 | 125 | 180 | |
| 28 | 54 | 60 | 65 | 85 | 105 | 150 | 210 | |
| 32 | 58 | 65 | 75 | 90 | 120 | 160 | 240 | |
| 37 | 67 | 75 | 90 | 105 | 135 | 180 | 270 | |
| 43 | 75 | 85 | 100 | 120 | 150 | 210 | 300 | |
| 45 | 80 | 90 | 105 | 135 | 165 | 240 | 330 | |
| 52 | 95 | 105 | 120 | 150 | 180 | 260 | 360 | |
| 60 | 110 | 120 | 135 | 180 | 210 | 300 | 420 | |
| 65 | 120 | 135 | 150 | 195 | 240 | 330 | 480 | |
| 73 | 135 | 150 | 170 | 210 | 260 | 350 | 520 | |
| 85 | 150 | 165 | 180 | 240 | 300 | 400 | 600 | |
| 90 | 165 | 180 | 210 | 260 | 320 | 440 | 640 | |
| 105 | 190 | 210 | 240 | 300 | 370 | 500 | 740 | |
| 120 | 220 | 240 | 270 | 340 | 420 | 570 | 850 | |
| 135 | 240 | 270 | 300 | 380 | 470 | 640 | 940 | |
| 150 | 270 | 300 | 340 | 430 | 530 | 720 | 1050 |