June 9, 2008


Your Three Key Elements
For A Perfect Exposure

Your digital camera has preset exposures for taking pictures so all you have to do is point and click right? Well, not always…There will be times when you’ll need to make certain adjustments for better photographic results. In my last blog I wrote about two of these key elements; shutter speed and aperture. The third is your ISO, which is the digital sensor’s sensitivity to light.

Now I will put it all together and show you how they work in sync:

The shutter speed controls the amount of time you allow the light to strike the sensor. Let’s say you have a shutter speed setting of 1/500 of a second and the picture you took was too dark. “Open up” one stop, and change the shutter speed to 1/250 of a second. This allows the shutter to stay open twice the length of time as the 1/500 of a second. To decrease light “stop down” one stop to 1/500 of a second which allows half the amount of time and light?

Smaller numbers give you 100% more light and larger numbers give you 50% less light. Use shutter speed when you want to control or stop motion.

The aperture (f/ stops) control the amount of light that strikes the sensor. To increase your light “open up” one stop (f /5.6 to f/ 4.0). To decrease the amount of light “stop down” one stop (f/ 4.0 to f/ 5.6).

Again, smaller numbers give you a wider aperture and more light while larger numbers do the opposite. Use the aperture when you want to control the depth of field.

Caution here—this is a last resort! The higher ISO’s produce a grainy affect in the picture. In a low-light condition you would choose a “higher” ISO. In a bright-light condition you would choose a “lower” ISO. Settings of 100 to 200 will produce better quality pictures.

The higher the ISO number, the more sensitive it is to light which means it captures more in less time.

If you need to adjust the amount of light entering your camera, you can use any one of the three tools above. A correct exposure relies on the right combination of shutter, aperture and ISO settings. Remember, each gives you a different creative result.

Until the next time—Happy Shooting!

The camera doesn't make a bit of difference. All of them can record what you are seeing. But, you have to SEE.” ~Ernst Haas, Comment in workshop, 1985

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