Ready reckoner
Last updated:16 March 2017
| PHOTO SCALE | Total area of Photo | PHOTO | PP - PP* | PP - PP* | ||
|---|---|---|---|---|---|---|
| Acres | Ha. | Sq. kms | length of side | 60% Overlap | 80% Overlap | |
| 2,500 | 82 | 33 | 0.3 | 0.06 km | 0.23 km | 0.12 km |
| 5,000 | 327 | 132 | 1.3 | 1.2 km | 0.46 km | 0.23 km |
| 7,500 | 735 | 2"98" | 3.0 | 1.7 km | 0.69 km | 0.35 km |
| 10,000 | 1,307 | 521 | 5.3 | 2.3 km | 0.92 km | 0.46 km |
| 15,000 | 2,941 | 1,190 | 11.9 | 3.5 km | 1.38 km | 0.69km |
| 20,000 | 5,229 | 2,116 | 21.2 | 4.6 km | 1."84" km | 0.92km |
| 25,000 | 8,170 | 3,306 | 33.1 | 5.8 km | 2.30 km | 1.15 km |
| 30,000 | 11,764 | 4,761 | 47.6 | 6.9 km | 2.76 km | 1.38 km |
| 40,000 | 20,915 | 8,464 | "84".6 | 9.2 km | 3.68 km | 1."84" km |
| 50,000 | 32,679 | 13,225 | 132.3 | 11.5 km | 4.60 km | 2.30 km |
| 75,000 | 73,528 | 29,756 | 297.6 | 17.3km | 6.90 km | 3.45 km |
| 80,000 | 83,658 | 33,856 | 338.6 | 18.4 km | 7.36 km | 3.68 km |
| 100,000 | 130,715 | 52,900 | 529.0 | 23.0 km | 9.20 km | 4.60 km |
* PP-PP = Principal Point to Principal Point