|
 |
Film speed is a standardized way of measuring the light sensitivity of a certain film or digital capture device. The terms ASA (American Standard Association) and ISO (International Standards Organization) are the standards by which we measure the light sensitivity. The higher the ISO, the more sensitive the film or device is to light.
The advantage that digital has over film in this subject is that you can change you ISO setting on a digital camera during a shoot, so you have the ability to capture images in a verity of lighting situations without having to change your film or use a second camera with faster film loaded in it.
(Click on any image below for an enlarged view.) |
Topics Covered:
- ISO explained
- Setting the ISO on the EOS Rebel
Equipment Used:
You can click on the blue links below for more info.
ISO explained
The term ISO (what used to be known as ASA) is used to measure the speed of photographic film/digital capture device. The higher the ISO rating the faster the film/device is, and fast film affords better exposures in low light situations.
The tradeoff is that the faster the film gets, the more the grain or noise size increases giving the final image a fuzzy look.
We have found that higher ISO numbers in digital cameras result in increased noise rather than larger grain. Notice the noise that appears in the shadow of this remote control unit as the ISO is increased (figure 1).
(Click on image for a larger view.)
|
 |
|
Setting the ISO on the EOS Rebel
Out of the box, the Rebel is set to the Auto setting. This means that the camera will determine the best speed setting for the given situation. When you have the camera set to any of the preset shooting modes, the camera will also set the ISO based on the program setting you chose.
When you are not in a preset mode, you can adjust the ISO with the controls on the Rebel. To make these adjustments, first press the ISO button on the back of the Rebel then use the Selection dial to set the desired ISO setting (figures 2 and 3).
|
|
|
The available settings for the EOS Digital Rebel are 100, 200, 400, 800, and 1600. Remember that the higher you go the darker the lighting situation you can shoot in but you will see a decrease in image quality due to the added “noise” as you approach the higher settings. |
|
Recommended Links
- To learn more about Photoflex equipment, go to www.photoflex.com
- For more tips and techniques on lighting and cameras, visit
www.webphotoschool.com
and sign up for access to the Member Lessons.
|
;)
;)
;)
;)