Camera Modes

Auto ISO modes

Written by Digicamhelp Editor

Auto ISO modes automatically select the ISO according to the light level of a scene. This means that the user has no control over which ISO number is used. This may…or may not…be a good thing.

Auto ISO mode

All consumer digital cameras have an Auto ISO mode. The camera automatically selects the sensitivity, known as ISO, according to the level of light in a scene. The user has no control over which ISO number is used.

In bright light a lower ISO will be selected. In low light an higher ISO number will be selected.

Auto high ISO mode

Some compact digital cameras have an auto high ISO mode that is primarily used in very low and difficult lighting. The camera selects ISO numbers higher than auto ISO mode, usually ISO 400 and above.

Higher ISO means faster shutter speeds

When a higher ISO is selected, shutter speeds are faster and apertures open wider, allowing more light to enter the camera. Use of faster shutter speeds helps prevent blurred images due to camera shake. When using high ISO numbers, you may not have to use a flash.

Higher ISO means more image “noise”

Keep in mind that the higher ISO, the more noise appears in images. That’s why many photographers, in order to prevent noise, prefer to set ISO manually and select low ISO numbers even if they must use a tripod to prevent camera shake. Still, an photo with noise is better than no photo at all.

Image noise will be higher when using Auto High ISO mode than using Auto ISO mode. Whenever possible, manually select ISO and use the lowest ISO setting possible.


  • d jones, if the card is a Secure Digital memory card, it has a lock on the side of it. Slide it the opposite of the current position and it will unlock the card.

  • Please tell me what “card locked” means.  I loaned my camera to a friend and when received back that is what its saying and i cannot delete pictures the friend took.  Please Help!!!!

  • Not all cameras are created equal when it comes to high ISO performance, especially when it comes to compact digital cameras. If you have a compact camera that does well in low light then, yes, you may be able to give up using a flash in low light by increasing the ISO. Just don’t forget to change the white balance setting to match the lighting if you’re shooting indoors.

  • None of this novel before, and this information very valuable and useful in any case that the use of a camera with ISO means to give up the flash so is your opinion?!