What is ISO in Photography

Many people entering in the world of photography may not understand what is the true meaning of ISO terminology in photography. To explain more regarding this and for the benefits of those individuals who ask me what is that (ISO) and what is the effect of the said ISO in thier picture.

What is ISO?

It is the film speed scale or the sensitivity of a film to captured light...

I am using digital camera, not Film is there an ISO on it?

Yes, all digital camera (compact, point and shoot, SLR, mobile camera)they have an ISO,

ISO sensitivity expresses the speed of photographic negative materials (formerly expressed as ASA).

Since digital cameras do not use film but use image sensors instead, the ISO equivalent is usually given.

ISO speed affects the shutter speed / aperture combinations you can use to obtain correct exposure.Suppose your digital camera's light meter warns you there is not enough light to correctly expose a scene. You could use the on-board flash, but let's suppose again it's not allowed (like in a concert or indoors recital).
You would then need to use a higher ISO. Set on "ISO Auto" mode, your digital camera will automatically select a higher ISO. Otherwise, you can manually select the next higher ISO and see if the increased sensitivity allows you to obtain a correctly exposed picture. If it does, you can now take a correctly exposed picture.

Now you use higher ISO setting, but after you took a picture you are not happy with the output because of some gain or called it "image noise" in your picture... That's the effect of using higher ISO...

What is "Noise" in the photo?

How to handle or elliminate those Noise in the picture?

See my next topic......