How to Choose the BEST ISO For Every Photo

Before diving too deep into chit-chatting about choosing the BEST ISO for every photo, I want to define ISO quickly. ISO is the acronym for the International Organization of Standardization. This Organization sets standards for a camera's sensitivity rating or sensitivity to light in a scene given the chosen ISO setting. Therefore, ISO is an essential part of the exposure triangle settings for any given photo.  

Regardless of the genre of photography, ISO adjustments will increase the camera sensitivity to light (higher ISO value) or decrease the camera sensitivity to light (lower ISO value). However, what is unique to landscape photography is that ISO can usually be set at its best value for most landscape scenes.  

So the obvious question here is, "What is the best ISO for a landscape setting?" 

ISO 64, 14mm, f10, 1/1600 SS

Now you're probably hoping I'm going to give you an exact ISO value here, and I will... kind of. In most situations, the best ISO for landscape photos is the camera's lowest native ISO value. For example, using my Nikon Z 7ii, I usually set my ISO at a value of 64, as this is my camera's lowest native ISO. In contrast, my Nikon D810 will typically be dialled in at an ISO value of 100.  

As noted earlier, ISO balances the exposure triangle settings. If I need a faster shutter speed to prevent motion blur due to a handheld camera or blustery scene, then the best ISO for that situation might not be my camera's lowest native ISO. In other cases, I might want to reduce my ISO further to allow for a longer shutter speed in a situation where I don't want to use an ND filter. Additionally, there's the whole issue of landscape photography at night. Higher ISO values upwards of ISO 3200, 5000 or 6400 might be necessary to capture those star-studded skies. 

You might also be wondering why it's important to make a good choice in ISO. The simple answer is that using as low an ISO as possible will facilitate higher quality images, usually with lower noise.

So when choosing an ISO value for a landscape setting, the best setting will always be the lowest ISO possible to create a well-exposed image given the environment and the desired creative outcome.