Exposure table for a Canon A520
I plan to play around with the manual modes of my new A520. To help, I wrote a little Python program that generated the following table. The main formula is shutter time = aperture2 / 2EV. This table should appeal to programmers (even more so if the aperture values were not rounded off).
.----------- EV -------------. .---------------------------- Shutter Speed --------------------------------. ISO50 ISO100 ISO200 ISO400 f/2.6 f/3.2 f/3.5 f/4.0 f/4.5 f/5.0 f/5.6 f/6.3 f/7.1 f/8.0 0 -1 -2 -3 14 20 25 32 41 50 63 79 101 128 1 0 -1 -2 6.8 10 12 16 20 25 31 40 50 64 2 1 0 -1 3.4 5.1 6.1 8.0 10 13 16 20 25 32 3 2 1 0 1.7 2.6 3.1 4.0 5.1 6.2 7.8 9.9 13 16 4 3 2 1 0.8 1.3 1.5 2.0 2.5 3.1 3.9 5.0 6.3 8.0 5 4 3 2 1/2 0.6 0.8 1.0 1.3 1.6 2.0 2.5 3.2 4.0 6 5 4 3 1/5 1/3 1/3 0.5 0.6 0.8 1.0 1.2 1.6 2.0 7 6 5 4 1/9 1/6 1/5 1/4 1/3 1/3 1/2 0.6 0.8 1.0 8 7 6 5 1/19 1/12 1/10 1/8 1/6 1/5 1/4 1/3 1/3 0.5 9 8 7 6 1/38 1/25 1/21 1/16 1/13 1/10 1/8 1/6 1/5 1/4 10 9 8 7 1/76 1/50 1/42 1/32 1/25 1/20 1/16 1/13 1/10 1/8 11 10 9 8 1/151 1/100 1/84 1/64 1/51 1/41 1/33 1/26 1/20 1/16 12 11 10 9 1/303 1/200 1/167 1/128 1/101 1/82 1/65 1/52 1/41 1/32 13 12 11 10 1/606 1/400 1/334 1/256 1/202 1/164 1/131 1/103 1/81 1/64 14 13 12 11 1/1212 1/800 1/669 1/512 1/405 1/328 1/261 1/206 1/163 1/128 15 14 13 12 1/2424 1/1600 1/1337 1/1024 1/809 1/655 1/522 1/413 1/325 1/256 16 15 14 13 1/4847 1/3200 1/2675 1/2048 1/1618 1/1311 1/1045 1/826 1/650 1/512 17 16 15 14 1/9695 1/6400 1/5350 1/4096 1/3236 1/2621 1/2090 1/1651 1/1300 1/1024 LV -5 Scene lit by the full moon -4 -3 -2 -1 0 Defined as light requiring 1 second exposure at f/1 and ISO100 1 Dark scenes outdoors at night 2 Typical night street scenes 3 Brightly lit night street scenes 4 5 6 7 Typical indoors; light outdoors about 10 minutes after sunset 8 9 10 Dark, dreary overcast day in Boston, London or Paris 11 12 California bright overcast 13 Typical shadow cast in a daylight scene; cloudy bright days 14 Typical light level for side-lit daylight shots in good afternoon light 15 Gray card in full sunlight 16 Light gray object or skin in full sunlight 17 White object in full sunlight