If you had started in photography when most pictures were taken using B&W film then it is possible you have heard of this rule and made use of it. Before the introduction of reliable exposure meter systems built in to a camera a photographer learnt how to “read” the scene’s light to decide on the correct shutter speed and aperture (f/stop) they would need to get the shot. Most photographers were not that experienced and would make use of a hand held light meter to achieve the same result.
With digital cameras now being 100% dependent on having a working exposure system you are unlikely to have to figure out the exposure variables before shooting.
But, as a little exercise see how you camera stacks up against “The Rule”. I used a Nikon D3 for this exercise. At midday I pointed the cmera at a suitable scene and set the ISO to 200, f/stop to f/16 and shutter speed to the reciprocal of the ISO, namely 1/200 sec and then pressed the shutter release. I then took another shot using the same ISO but set the camera’s auto exposure system to work and it delivered the picture with a shutter speed of 1/100 sec. In other words the auto system is over exposing relative to the Sunny 16 Rule. What’s going on here.
Simple – it is after all a Rule of Thumb and it was designed to give a reasonable exposure in the B&W film days. If you are going to use this to amaze your friends with your skill of not needing an exposure meter don’t forget to experiment and see if you have to add or subtract any shutter speed or f/stop to get the exposure you want. Apply that adjustment for when you are shooting and on a sunny day the results will speak for themselves.
Of course if cloud intrudes that will lower the amount of light and you have to give more exposure to achieve a well exposed image. But that is for another day.
Mosaic Images Photography has a range of wildlife, nature, flora and abstract pictures that will look great on your walls or as an Instant Download for your screen saver, digital picture frame or TV slide show.