Understanding ISO

The ISO number relates to the sensitivity of the camera to the surrounding lights. Now when there is too much light around, the camera need not be too sensitive of the light around as there is enough light for the sensors to pick up from. In case there is low lighting, the use must tell the camera to be extra sensitive to the light around so as to capture the maximum possible light. Thus ISO is a function which tells the camera how sensitive the sensor must be to the surrounding light.

                                     

The problem comes when the ISO is too high. As the sensors become extra sensitive to the light around, they try extra hard to capture what ever they can. This leads to capturing of noise around. This at very high ISO we will observe that the pixels in the photograph tend to break. If we use a high ISO in a well lit area, the photo will be so bright that it will almost be white as the sensor will try to capture all the light (even more than required)

Thus ISO setting depend on the following:

• Surrounding light: if the lighting is poor, increase the ISO but not too much. When there is sufficient light, Keep the ISO level low. This can relate to indoors (low lighting) and outdoors (high lighting) respectively.

                                     

• Photo detail: If more detailed photo is required, then the ISO must be kept low as the sensors capture what is visible to it. In case less detail is required but more brightness (brightness gets compromised when detail is increased and vice-versa) keep ISO high.

                                     

Conclusion:

• High ISO: low lighting, less detailed but bright photo required and indoors
• Low ISO: High lighting, more detail (natural colors) required and outdoors.