ISO stands for International Organization for Standardization.

That does not tell you what ISO actually means to you and your photo taking.

The ISO number on your camera basically sets the image sensor’s sensitivity to light. The lower the ISO, the less sensitive your camera is to light.The higher the ISO, the greater the sensitivity to light and the less light that is needed to take a picture.

Here it is in its simplest form.

A low ISO setting provides higher-quality images. However, because the image sensor is less sensitive to light, your camera shutter needs to stay open longer to let enough light in to make a photo. On a bright sunny day, it won’t be a problem as that plethora of light will make for a snappy (and snazzy) photo. Indoors, however, is a different story.

Here is a tutorial based on indoor light.

On my Canon I hit the “ISO” button on the back of my camera. I set the ISO to 100 and took a photo of these sunflowers (from our garden!) that were on my table.

There was a two-point-five second time span where the shutter stayed open. This was the result.

I could have used my tripod, but that would defeat the purpose of this tutorial. I had propped my arms on the table and did my best to stay still.

I then changed the ISO to 400. There was a point-eight of a second time span where the shutter stayed open. Here is the result.

This one was not as shaky and in better focus.

I then switched the ISO to 1600. High ISO = really sensitive to light = you can take photos in low light (With no flash!) that might actually be in focus.

The following photo is an example. There was a one-sixth of a second time span where the shutter stayed open. Very fast.

Sunflowers are so pretty.

The downside to using the high ISO numbers is that you can get “digital noise”, which means that your photos may not be as crisp as you would like them to be. This happens more when it is a lot darker and your lighting possibly consists of household lights after the sun has set.

For most everyday shooting, you’ll want your ISO to be at 400 or less. On a sunny day you will want to start at ISO 100. Bump it higher only when need be; you do not want to give up image quality if you do not need to.

You may want to bump up the ISO when shooting indoors in order to get shots that are in focus. Sometimes a little digital noise is worth a photo that is not a complete blur.

The joy of digital photography is that you can change your settings on the fly in order to take the best photo possible in the conditions you are presented with.




Angella is a servant of God. She is also a Wife of One and Mom of Three. Apart from this she is a Photographer, a Writer, and a Chartered Accountant. She tries to balance it all and fails miserably. Her daily trials and tribulations are documented at www.dutchblitz.net. Brace yourselves.