In photography an "ISO" is a type of measurement to show how sensitive to light a film is. Of course digital cameras and mobile phones don't use film, the principle is the same, it's how much light a photograph needs to take a good picture. The higher the "ISO" number the better it is basically. What we've got here are 4 similar images taken with a HTC Wildfire. The images are shot in 800, 400, 200 or 100 ISO (there is also the "Auto" option) and you will swiftly see the differences between them.

This image was taken with the ISO setting put to 100, it's dark and despite being taken in a very well lit area is murky and moody. Although it feels like it's been drained of colour and life you can see why people would want to use this sort of an option on the phone, pictures of things like graveyards would become darker and scarier.

This image was taken with the ISO setting put to 200. As you can see some of the light and colour has come back into the the picture. Although nothing looks particularly bight or vibrant it looks more like the room is just badly lit than anything else. Again this could be used to give images various atmospheric effects, though for the picture for me here it still feels a bit too dark.

This is the image taken with an ISO setting of 400 and is infact probably the best picture out of the 4 images. The image has plenty of light and yet is over exposured, it's light but it's real light and it doesn't look over the top bright. Although the image isn't as "true" as the 800 image below it's probably the best image as it dims down the bright light that was behind the camera.

This is with the ISO set to 800, it's the brightest of the images though due to the strong lighting in the room it's probably slightly too bight. The image is more "true" than the image above it though sometimes a little less honesty is a good thing. Generally if you're in a darker area this is the better setting though leaving the phone on Auto will generally be the best unless you are looking for a particular setting for a specific photo.

This was the image when the setting was put to "Auto", it appears to me to resemble the 400ISO image from above which would back up the idea that the 400ISO picture was the best choice for this particular image. Of course you should give the ISO settings a play about though to see what suits your particular subject matter.

To select the ISO setting on a HTC Wildfire you need to open the camer and then the Camera's menu then the settings option and ISO is the second option down below "White balance" which is another very over-looked feature that I'll be blogging about at some point.