Lesson 3 - Exposure

Determining the correct exposure for an image is essential to creating images that are award winning and images that convey the emotion and feeling you desire.The correct exposure is a combination of the shutter speed, f/stop (aperture), and ISO.

Exposure = Shutter speed + f/stop + ISO 

 1/8 second + f/5.6 + ISO 640

1/8 second + f/8 + ISO 1000

1/8 second + f/11 + ISO 1600

All of these settings produce the same exposure 

The correct exposure is determined by the lighting situation

and what the subject is doing.

Photographing a basketball game with available light.

Fast shutter speed + low f/stop + higher ISO 

Outdoor portrait on a sunny or over cast day. 

Slower shutter speed + low f/stop + low ISO

When any one of the variables: shutter speed, f/stop, or ISO change, then one other variable must also change.

If you are shooting in a dark environment, but need a fast shutter speed, you must increase your ISO and open the lens aperture to allow more light to hit the sensor.

Beware of changing the ISO. Every camera has its own lowest ISO point. It is this point that will produce the most noise free images. Last year a client came to me with her camera. Frustrated with the way her images were appearing. Upon looking at her images, I noticed that any image she shot outside was beautiful. Yet every indoor or low light situation was very poor. Her camera’s lowest ISO was 50. An ISO that is designed for bright sunlight. Once she increased the ISO, she introduced large amounts of noise.

To sum this all up: let your subject and creativity decide the correct combination. Your camera has a shutter priority mode, aperture priority, and program mode. Play with them until you get comfortable manipulating the variables.

Let me know if you have any questions.

Keep shooting!!

John 

This entry was posted on February 2, 10 at 08:28 and is filed under Lessons. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response or trackback from your own site.