ISO is a very important tool all photographers at some point take advantage off. ISO also known as the International Organization for Standardization, controls the cameras overall sensitivity to acquired light within the lens. Using ISO properly can help you to get some incredible shots especially when the weather outside is cloudy and shooting conditions are poor. Light photography is a crucial element to getting a picture at all, with too little light you will need to turn up your ISO, with too much light your ISO needs to be turned down. But when ISO is introduced, it is debated that it can cause a term known as "noise." Noise is essentially a slight static that is within your images, and it ends up making them look grainy and unnatural. Some argue that ISO is not to blame for this while others argue it is, regardless, if used correctly its won't matter too much to the average photographer if used properly. But once you are more advanced it is important to get an understanding for the goods and bads of using ISO as you will 100% be forced to use it out in the field.

Example of ISO

The photo above taken by MrBrianJames displays exactly how different amounts of ISO will appear in your final product. For this specific scenario low ISO looks much better, why? The only light on the street is the signage covering miles of the sidewalk; to over exemplify the fierce glow of these lights we use less ISO to make the image darker, creating a high contrast between the lights and their surroundings. Now let's say we were in a scenario where the street was much darker, we would need around 2000-4000 ISO to brighten up the image so we can see our subject in focus. This is a very typical scenario for shooting out in the forest, essentially because of the dense coverage of the treetops and the lack of light coming through.