Wednesday, May 5, 2010

Understanding Exposure (Part 1 of 3)

There are three main factors to consider when you look at exposure.  Shutter Speed, Apeture, and ISO.  Below is Part 1 of 3 on understanding exposure.  I will likely do a wrap up after part three to include the camera meter and histogram so stay tuned.

Shutter speed
The shutter speed of your camera is the measure of how long the shutter remains open to expose the sensor. Any motion that occurs while the shutter is open will show on the image. (the faster the shutter speed the more likely you are to freeze the movement). Shutter speeds are based on the doubling or halving of seconds. The following is a general list of the most common shutter speeds from long to short: 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, 1/4000, 1/8000. As you can imagine the 1/8000 of a second shutter speed would just about freeze any movement.  The shutter speed for Image 1 below is 1/20th of a second.  This by no means freezes the movement but you can see that much of the movement was stopped.  The shutter speed for Image 2 was 1.1 seconds allowing the movement to blur the image.  Really it depends on what type of image you are going for.  If you have any questions please feel free to contact me.

Image 1

Shutter Speed: 1/20 sec

Image 2

Shutter Speed: 1.1 sec


  1. OOOOOOOOOh. I get it.

    That ancient film Minolta had a VERY quick shutter speed that drops would freeze in photos.

    I always wondered how photographers got that gentle blur to water. Wow. Steady hand!


  2. The steady hand would be a tripod... No way I could hand hold a 1.1 second shot and it be clear. I might be going to Big Creek, NC in the next few days so there will certainly be more to follow.

  3. Very nice way to explain Shutter Speed, better than any book around

  4. Thanks Roberto! Exposure was something I struggled to understand in the begining. Once you get it though you can really start playing around with your images.