This tutorial is for you if you need help with how to rate film. I’m covering everything you need to know and sharing how I rate the most popular film stocks like Portra 400, Portra 800, and Kodak Gold 200.
Check out this post here if you still need help metering your film.
How To Meter Film
Rating in film photography is choosing what to set your ISO at. Whether in camera or with a light meter is up to you.
Unlike digital photography, the ISO of the film is set using chemicals within the film stock. But most people manipulate the ISO to allow more light to reach their film, creating the different colors and tones that made film photography so renowned.
To rate at box speed set your ISO to match your film speed—for example, shooting at ISO 400 for Portra 400 or ISO 800 for Portra 800.
Film needs a lot of light. Like, a lot a lot. So to get the best exposure when shooting film, aim to over-expose by 1-2 stops. Do this by lowering the ISO.
If you’re used to digital photography, this can seem counterintuitive. But since the ISO is already set within the film itself, when you set your light meter to rate at a lower ISO, you are making it think you are working with a less sensitive film.
Metering is the physical process of using your light meter to determine your camera settings.
Rating is deciding what ISO you will set your meter at based on what film stock you’re shooting.
Portra 400 does well with rating at box speed. If you’re in pinch, set your ISO to 400 and have no fear. But if you have the light, I love rating it at 200. This gives you one extra stop of light which makes the shadows a little cleaner and gives you a nice safety net, ensuring you won’t underexpose your film.
Since the discontinuation of Fuji Pro400h film there has been an uptick in the use of Portra 800. Don’t let the 800 fool you, though. It still needs a lot of light. Maybe even more than Portra 400. For best results rate at either 400 or 200.
Kodak Gold is good at box speed but even better with just a little more light. Rate at 100 for best results.
Grace Paul is a mama, photographer, educator, and blogger. Film photography stole her heart and now she enjoys teaching other photographers how to bring more beauty to their lives and businesses through the art of film. Interested in learning more? Check out her educational resources here.