Understand Camera Aperture

Step 1

I like to refer to aperture as mainly my "depth of field". When I look at it that way I can determine how I want a picture to look. For example, when I take flower shots I like my aperture to be at the lowest it can be, which at 18mm is 3.5 and at 55mm 5.6.

Step2

To understand the figures you should know that The lower the aperture than the more depth of field you will have. Such as an aperture between 3.5-8.0 Please see image for details:

Picture
Make: Canon
Model: Canon EOS DIGITAL REBEL XTi
Shutter Speed: 1/125 second
F Number: F/5.6
Focal Length: 55 mm
ISO Speed: 200
Date Picture Taken: Jan 15, 2009, 4:02:37 AM

Step 3

Now, the higher the aperture than the more detail you will have in a picture. Usually those figures range between 8.0-22 and all the way up to 38. Please view image for more details:

Make: Canon
Model: Canon EOS DIGITAL REBEL XTi
Shutter Speed: 1/350 second
F Number: F/16.0
Focal Length: 55 mm
ISO Speed: 1600
Date Picture Taken: Jan 10, 2009, 5:01:22 AM

Step 4

When basing a photo directly off of aperture alone you have to remember to set your shutter speed and iso so that the image comes out correctly.

Step 5

To determine what setting iso you should use just remember that during the day (while sunny) you can a very low iso, such as 50-400 and during a sunset, cloudy day or at night you must use an iso of 400-1600 to accurately determine details.

Step 6

The shutter speed is also a big deal when it comes to letting light in. While taking photos during a sunny day or a well lit area you can use a shutter speed between 1/45-1/350, I usually use 1/125 to do outdoor flower shots in the sun.

Step7

And lastly, while photographing during the night or a sunset and cloudy day you might consider using a very low shutter speed, especially if you plan on shooting the stars. But-In general the shutter speed determines how long the shutter will stay open.