Monday, November 24, 2008

Shutter Speed

Today we are going to look at the last of the basics that I want to cover before we move on to other things.

We learned already how ISO is a measure of the sensors sensitivity, affecting how much light is needed to make a picture, and Aperture affects how much light can get to the sensor in a certain amount of time.

The shutter speed is what determines how much time the camera has to gather the light to make a photograph. In daytime photography the shutter speed is usually measured in fractions of a second. When the light gets dimmer like during the evening or night time, shutter speed could easily become more than one second in order gather enough light.

As an example, to take to take the picture of the building below during day light took only  1/1000 of a second


But if you are taking pictures in lower light you probably won't be able to get shutter speeds that fast. This next picture was taken at eight o'clock at night. It took 481 seconds, or an eight minute exposer to gather enough light to make a photograph.


These of course are some extreme examples, but some thing that you might want to keep in mind is that your shutter speed has a big effect on how sharp your pictures are. This is because one of the most common causes of blurry photo's is camera motion. The reason is the camera is actually moving while the shutter is open because its impossible to hold a camera perfectly still while taking a picture. If the shutter speed is fast enough then the camera's slight movement isn't enough to make the photo blurry. If the shutter speed drops low enough, then you will get a blurry photograph, even if the subject is motionless and the focus is perfect.

To illustrate I have two photo's of the same painting taken at two different shutter speeds.The first image as you can see was taken at 1/6'th of a second. It came out blurry so I bumped it up just a bit to 1/8'th. Roll your mouse over the image to see the results.

So thats shutter speed. I don't update as often as I should, but soon I will try and tie all of this together and then we'll see what we can do with this knowledge, even if we have an automatic camera.

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