Project 52

What is ISO in Photography? ISO stands for  International Organization for Standardization.

In photography ISO or ASA (American Standards Association) is the sensitivity of the film (traditional photography) or image sensors (digital photography) to capture or to register images.

In Film Photography – ISO film was measured in numbers like 50, 100, 200, 400, 800 and the last value I encountered was 1600.

In Digital Photography – ISO measures the sensitivity of the image sensor. The same principles apply as in film photography.

In both digital and film photography, the reduction of exposure corresponding to use of higher sensitivities generally leads to reduced image quality (via coarser film grain or higher image noise of other types). Basically, the higher the film speed or sensitivity, the worse the photo quality.

Sample Images for Exposure using lower to higher ISO (images are shot with same aperture and shutter speed only the ISO setting was change)

Sample Images Picture Quality Using lower to Higher ISO

Grain is essentially how nice your photos look. Most of the time, you won’t be able to tell the difference in grain at standard print size of 4×6. However, if you ever have a photograph you’d like to enlarge, ISO suddenly becomes very important. The higher the ISO, the grainier your photo will look. On the above image I cropped just a part of an image, one at ISO200 and the other at ISO1600. The first photo looks sharp and more details, while the second looks well but  has grain or blur . Most consumers won’t need to be making a lot of enlargements, so this doesn’t always matter. But even an amateur will sometimes get that one perfect shot they just would love to hang on their wall. Unfortunately, if that perfect shot was taken with a high ISO film, or using a high ISO setting on a digital camera, the size of the enlargement will be limited before it starts to look bad.

Use of Lower ISO – lower ISO can be use in outdoor (day light) photography, or in studio with the helps of studio lighting equipment.

Use of Higher ISO – higher ISO can be use in indoor photography or places with less light like bars, concerts, indoor sports, etc…

But now a day’s digital camera manufacturers are trying to develop a camera sensors capable of capturing a low noise or grainy images while using higher ISO.