Photography Basics: Learning How to Use Film Speeds

Cameras have lots of little knobs, dials and meters. If you stare at your camera long enough, you’ll be amazed at how many ways you can adjust your camera and change how your pictures look. But did you know that one of the most critical decisions you can make when preparing to shoot happens before you even load your film?

The speed of the film you use is one of the very few unalterable qualities of a photograph. There are plenty of ways to toy with aperture, exposure, and focus. However, once you select your film and load it into the camera, there is no way to change how the film reacts to light. In every picture you take with film, you’re adapting to the film speed. Film does not speed up or slow down to suit your needs, so it is important that you make the right call the next time you head out for a fresh roll.

What is ISO?
Film speed measures how sensitive your film is to light. Low film speeds mean that the film is less sensitive and needs a longer exposure while high speeds are very sensitive and need shorter exposures. The speed of a film is commonly known as its ISO. Any film you buy will have its ISO marked on the box, and common speeds are 400, 800, and 1000, with 400 being the closest to the “standard.”

The ISO of your film affects every aspect of the way your camera works. Your light sensor (if you have one) has to be set correctly for the film you’re using, your aperture will be more or less limited depending, and your shutter speed will likely have to decrease or increase to accommodate the film. Even digital cameras use a simulated (and adjustable) “film” speed that they base their calculations on.

Choosing the Right Speed
The ISO of the film determines what you’re able to photograph and how. Because high-speed film (ISO 800 or above is a good general rule) requires less time to expose, you can shoot images with much higher shutter speeds than with a slower film. The end result here will be crystal clear action; fast film is wonderful for shooting sports or anything that moves quickly. When you see a picture of a basketball player suspended in mid air, you know that the image was probably taken with high speed film. With a slower ISO, the player in the picture would likely be a big blur. Faster film also requires less light and can be very useful in an indoor situation where a flash is not appropriate.

Lower speed film captures more detail because it has more time to absorb light. It’s important to keep the words “detail” and “blurry” separate- more “detail” in a picture is similar to a high definition TV having more “detail” than a regular television- more of what was originally there will be seen in a photo. The more time the film can “see” a scene, the more accurately the scene will be represented. Lower speed films are great for images like portraits where you want to show great depth of field.

Film Speed Experiments
To get a good handle on how ISO works and what it does to your images, here are a couple of things to try out the next time you’re planning a shooting day:

• Get rid of your flash (if you have one) and take some fast film into a low light environment
• Swing by a local high school, college, or little league game and try shooting (with permission) two rolls of film – one very slow (ISO 100) and one very fast (ISO 1000) – then have a look at how different the images turned out

Film speed is one of those great things to play with when you’re pretty comfortable with your camera and you’re looking for new ways to challenge your perceptions. Each speed has strengths and weaknesses, and it’s up to you to decide which one works for you. Now it’s time to take some pictures you’ll be proud to display in wall picture frames And don’t forget that pictures make great gifts especially when given in pictures frames that complement the existing decor like natural wood picture frames and classic silver picture frames.

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