ISO Uses

Content

So ISO, what is it? There's a common myth that if you have bad lighting you should turn up your ISO in order to compensate, this is not true or advisable as this will lead to 'noise' being on the film which lowers the quality and overall makes it appear worse than keeping it at recommended.

What does it actually do? It makes the lens and therefore the camera itself more sensitive to light and will make it either over or under expose images but the general rule of thumb is that you should keep it between 100-400 and work with the appature or Shutter Speed rather than risk over-exposure and adding noise to a scene.

This image helps to demonstrate this point better and gives you a clearer picture of what effect that ISO can have on pictures.

On the left is an image with an ISO set to 100, the image is clean and crisp with detail and the colours are whole. On the right is an image that's full of noise (the grain over the front of the image) which has ruined the detail and diluted the colours of the sky and the building making appear to be of a worse off quality and almost seemingly from another camera.

To try and emphasise this point more I shot a few of my own videos to try and show you what effect ISO can have in different environments.

Here is an image with the ISO set incorrectly: 

As you can see by the highlighted spots on the frame there's a lot of grain and noise on the image and that's because of incorrect ISO settings for the lighting and environment making it a worse looking final product overall.

Here we have an example of a good use of ISO within the environment, having a low ISO in high key lighting will produce good results as the camera becomes less sensitive to light meaning that the chances for noise and grain within the image are low.

It will also produce a more detailed image as the shadows will be more defined while the light still gets through the lens with just enough exposure for it to be a clear image

However these examples aren't really an exact science, there's still so many factors that could affect them. An example would be for the high ISO I shot at night with a singular point of low key light (a ringlight) which would give worse results than multiple at equal distances like as backlighting, or the fact that I didn't do multiple test shots of the day photograph to better test for the best ISO setting for that moment.

This doesn't mean that the footage looses impact, the points are still made within a dark setting and lowkey lighting (like a studio with a singular point) a higher ISO would be preferable as it would make the camera better able to detect and then use the lighting available, whereas a more highkey lighting setting would require a lower one to draw out the images quality and reduce the amount of noise seen in the final product.

Hopefully this has given you a better understanding of how impactful the ISO settings on a camera can be for the product you're producing.

Have a great day.