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7. Exposure Rules
The classic advice is, "Expose for the highlights, and let the shadows take care of themselves." This works with slide film and digital. But with negative film, especially color negative, you're better off overexposing by one stop.
8. Quick Flash-fill Rule
When using an automatic flash unit that doesn't provide auto flash-fill ratios, set the flash's ISO dial to twice the ISO you're using. Meter the scene, select an f-stop, set the autoflash aperture to the same f-stop, and shoot. The resulting 2:1 flash-fill ratio will produce filled shadows one stop darker than the main subject.
9. Flash Range Rule
Want to know how much extra flash range you get by going to a faster ISO? The rule is, "Double the distance, four times the speed." For example: If your flash is good to 20 feet at ISO 100 (film or digital), it will be good to 40 feet at ISO 400.
10. Megapixel Multiplier Rule
To double the resolution in a digital camera, you must increase the number of megapixels by a factor of four—not two. Why? The number of pixels in both the vertical and horizontal dimensions must be doubled to double the pixel density across the image sensor.
11. Action-stopping Rules
To stop action moving across the frame that's perpendicular to the lens axis, you need shutter speeds two stops faster than action moving toward or away from you. For action moving at a 45-degree angle to the lens axis, you can use a shutter speed one stop slower. For example: If a person running toward you at moderate speed can be stopped at 1/125 sec, you'll need a shutter speed of 1/500 sec to stop the subject moving across the frame, and a shutter speed of 1/250 sec to stop him if moving obliquely with respect to the camera.
12. Sunset Rule
To get a properly exposed sunset, meter the area directly above the sun (without including the sun). If you want the scene to look like it's a half-hour later, stop down by one f-stop, or set exposure compensation to minus one.
Originally published November, 2004.
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