People often ignore ISO because they don't fully understand what it does, but once you do, you'll be making use of this clever tool all the time - and not only in low light conditions.

ISO is a kid of bonus exposure control which can help you out of all sorts of tricky situations.

In this video we'll explain

• ISO introduction
• How ISO works
• ISO range and shooting in low light
• Grain and noise
• When to use ISO rather than flash

Instead of using flash for this indoor portrait I increased the ISO speed to make the camera more sensitive to light. Why would I not use flash?

Small on camera flashes have a nasty harsh look to the lighting which looks so stark and unflattering. Watch the video and you'll see what I mean. As far as I'm concerned ISO speed is king.

Don't miss our Using ISO speed films...

• I Mess Up Salsibury Catherdral Photo Shoot - EP31
• Photographing A Landscape Landmark PT2 - EP30
• Photographing A Landscape Landmark PT1 - EP29
• Exposure Bracketing Explained - EP28
• Woodland Photography with Gary Gough - EP27