Shooting film allows you to create your creative aesthetic in how you shoot and how you choose to have your film processed. One of the main questions you will be asked is how you rate your film. Basically, the number you put as the ISO in your meter is what you are rating your film at.
So what is ISO?
ISO stands for International Standards Organization (sometimes denoted as ASA, which stands for American Standards Organization, on older film cameras). ISO is a measurement of how sensitive your film is to light. If you have a higher ISO then your film is more sensitive to light. Lower ISO film is less sensitive to light. Film stocks with high ISOs can be shot in low light scenarios (for example I love to pull put Potra 800 for my last roll of film at sunset when the light dips). Film with lower ISOs are best shot in bright sun (for example I love Portra 160 on the beach during high sun).
And before we talk about what it means to rate your film, let’s talk about what a box speed is:
Box speed is the ISO the manufacturer recommends shooting your film at. You can read it on the side of the film box or film canister. It is usually in the name of the film you buy as well (for example, Fuji 400 has a 400 ISO box speed, which means that it is recommended shooting it at 400 ISO).
So what does it mean to rate your film?
Rating your film is when you meter at a different rating than the box speed; this will change how your images turn out. I rarely rate my film at box speed. Each photographer is different so what you rate your film at will vary depending on the look you want to achieve. If you want that light and airy aesthetic, then most film stocks will need more light than their box speed recommends. Film works backward from digital in that it retains detail in the highlights, so it can handle quite a bit of overexposure. For this reason, I rate my film different than box speed. Rating is what ISO you tell your meter you’re shooting at. You can use this to overexpose or underexpose your images. For example, rating Fuji 400H at 100 ISO is the same as overexposing the whole roll by two stops, because you cut the box speed ISO in half, twice.
Once you start delving into it, it’s fun to see how you can adjust your aesthetic by how you rate your film! Give it a try and let me know your thoughts! And if you want to learn about why I shoot film, you can read my most recent post HERE.
