The basics in 15 minutes
There are excellent books and Wikipedia articles on this subject for an in-depth treatment of the subject. This is for the impatient who just want to get started filming and learn the details later (or maybe never).
These are the main parameters which determine how your filmed material will look
Shutter Speed
Higher values (remember 1/25 is higher than 1/100 although this is often misleadingly displayed as 25, 100, respectively) mean more light, i.e. your film/picture will be lighter. Higher values will also result in more motion blur, i.e. moving objects/people will appear blurred. It is really a matter of personal preference if you like the soft motion blur look or the “harder” sharp look. You see both used as an artistic element in many action movies, however, be aware that the latter might be hard to achieve with a low budget as the required amount of light for a motion-blur-free look is not always affordable if you don’t plan to shoot all your action shots outside in the sun (also see Lighting).
Aperture
This means how large the hole is through which your lens lets the light pass. There is a seemingly artificial numbering system (so-called f-numbers or f-stops) to describe how large that hole is. All you really need to know to get going is that a smaller number means more light and a narrower depth of field (if you don’t know what that is, read on, it will be explained later). This can become really important when enough light is a problem. One example from my experience: I own the GH1 which comes with a zoom lens with a maximum aperture of 4. I got a used Canon lense on Ebay which has a maximum aperture of 1.4, which means using the same shutter speed and ISO, I have 8 times more light with that lense and that can make the difference between a location being acceptable for a film or not. A term you often read in that context is “fast” for lenses which have a large maximum aperture (that means a very low number, confusing, I know).
Focal Length
Focal length is measured in millimeters and describes how much objects are magnified by your lens, i.e. how much closer they appear. Higher values mean more magnification and a narrower view. This is easy to understand and use by just looking through a lense an deciding if you like what you see. Other than that, the focal length also influences the depth of field, i.e. higher values mean narrower depth of field (see below). Lenses which allow you to change the focal length are called zoom lenses, i.e. zooming in means increasing and zooming out means decreasing your focal length.
ISO (Film Speed)
This is a concept that comes from analog film where you would use different film material with different chemical properties for different light conditions. The sensitivity of the film was standardized in ISO (100, 200, 400, 800 etc.), higher numbers meaning more light. This concept is also still used in digital cameras but there it’s obviously nothing chemical but just something artificial that results from digital magic performed by your camera’s sensor and the built-in software. What you need to know is that you normally pay a price for that extra light and that is noise. Noise means seemingly random inaccuracies in your pictures. The amount of noise generated for a certain ISO setting depends a lot on the camera. Cameras are getting better and better at eliminating that noise so just make test shots with your camera at the location under real light conditions and check which ISO setting look good (again a matter of personal preference, how much noise you like). However, less noise is preferable most of the time as it is much easier to artificially add noise later in an editing program than it is to remove noise.
Depth of Field (DOF)
The area along your view (Z) axis which is in focus has a certain length, i.e. objects being at least X meters and no more than Y away from the camera are in sharp focus, others are blurred. Y-X is called depth of field. What many low-budget film makers are after is a shallow depth of field, e.g. fiming a dialog between two people and only having one person in focus, because that is one thing that people associate with a “film look”. Here’s a summary what makes the depth of field more extreme, i.e. more shallow.
- Large aperture (remember that means a low number!)
- Large focal length (e.g. it is a lot harder to achieve shallow DOF with a wide-angle lense that with a telephoto lense)
- Short distance from the filmed object (the closer you are the easier it is to get shallow DOF)
lowbudgetactionfilms 