Setting Your ISO
This post will discuss how to utilize the ISO settings on your camera. ISO refers to the light sensitivity of your camera in digital cameras, or the sensitivity of the film if using film cameras.
The ISO is one of three parts to controlling the exposure of photographs you take.
1. Aperture, also known as f/stop (Read about Aperture here)
2. Shutter Speed
ISO has a unique quality to it that Aperture and Shutter speed does not, it controls the grain, or noise, in your image. The image below is a cheat sheet for ISO settings to noise/grain level in an image, but please note that this is not an exact cheat sheet and that sensitivity differs between cameras.
Grain/noise mean the same thing and refer to the speckles/dots you see in images. Grain is a term typically used with film photography, whereas noise is typically used referring to digital images.
Grain/noise is typically unwanted in professional photography services, but sometimes you can't help but to have some ISO in darker conditions. It is also good to note that if you only adjust ISO to increase your exposure, you will also lose detail due to the grain/noise.
So how do you increase your exposure without risking losing detail and without adding grain/noise? You adjust your aperture and shutter speeds! Open up your aperture (make the f/stop number smaller) and slow down your shutter speed. You can also utilize a flash, of course, just make sure to have a soft box over the flash, or another way to diffuse the light to avoid harsh shadows.
Grain/noise can be used purposefully in photography, for example, to make an image look more vintage.
I would highly recommend not avoiding grain/noise at all costs. I would recommend playing with your ISO settings on your camera and see at which setting you find the ISO to be acceptable or too much, and then think of the grain/noise with a creative mindset.
Photography is a science in ways, and in others, it's an art! Don't be afraid to experiment with camera settings.