Join Ben Long for an in-depth discussion in this video Understanding the basics of a camera, part of Introduction to Photography.
- Photographic technology advances quickly. The last 150 years have been a nonstop parade of change as we've moved from chemical-based imaging technologies to current digital offerings. Along the way we've also gotten, automatic focus, artificial lighting, faster performance, and much much more. Through it all though, the basics of the camera have not changed. It may sound strange but at a fundamental level there's no difference between your current digital camera and the earliest cameras of the nineteenth century.
All cameras, even your cellphone camera have the same basic components. They all have a light proof box. This holds the photosensitive material that will record an image and it has to be light proof because you're trying to capture and record light, so you can't have any extra light around. Most cameras also have a lens. This is a piece of material that gathers light that's bouncing off of your subject and refracts or bends that light to focus it onto the light sensitive material that's sitting in your light proof box.
Most lenses are glass, but they can also be made of plastic, water, any substance that can refract light. All cameras have an aperture. This is simply a hole in front of the light sensitive recording medium. Most cameras have an aperture that can vary in size, this is called an iris. But it's possible to have a tiny aperture of a fixed size which can do double duty as a lens. That's how a pinhole camera works. A camera must have a shutter. This is simply a door that can open and close for a certain amount of time to allow light to enter the light proof box.
By opening the shutter you expose the light sensitive material inside the box to the light that has been passed through the lens and the aperture. Now, photographers sometimes refer to a photo as an exposure because the process of photography is simply the process of exposing a light sensitive material to carefully focused light in a light proof box. Every camera ever made has had the components that we are talking about right now. In a way, photographic technology has been astonishingly stable throughout its history.
One thing that changed with great regularity is that light sensitive material that you put in that light proof box. In the earliest days you might have used wet chemicals smeared on glass plates, or complex mixtures of silver powders and saw dust or colored starches. I would argue that the most fundamental change in camera technology since its invention has been the shift from film to digital. In a digital camera we've replaced the light sensitive film, that used to sit in the back of the light proof box with a chip that's covered with light sensitive material.
We've also crammed in a computer and a bunch of storage which can read the signals coming from that light sensitive material and use all of that to produce an image. A lot of technologies remain constant at a fundamental level. All cars have had wheels with rubber tires, steering wheels, and an accelerator pedal even as they've gained fuel injection, electronic variable suspension, and cupholders. However, you don't need to know how fuel injection or carburetion works to drive a car. To use your camera well, though, you do need to understand the workings of some of these fundamental camera components.
To shoot well, consistently, you must know about some of the deeper workings of lenses, aperture, shutter, and your recording technology, be it film or a digital chip. Those are some of the things we're going to begin to study in the rest of this course. Now while fundamental camera parts have remained consistent, camera design has changed a lot over the last century and a half. This is partly because as film changed size new camera designs had to be created, but most new camera designs have come along to address a single problem.
Let's say I have a piece of film or an image sensor. In front of that I put a shutter, and then an aperture, and then a lens. With all that stuff in front of the imaging material, how can I actually see what I'm taking a picture of? The shutter is closed, which is blocking all of the light coming through the lens, and even it it weren't there's that piece of film or image sensor there behind the lens. The attempt to make a usable viewfinder has been one of the biggest factors driving camera design. But designers also have to factor in physical size, size of the recording medium, and much more.
Because of all of those reasons, there are several categories of camera that you can buy now. In the rest of this chapter, we're going to look at those different camera designs to help you understand the advantages and disadvantages of each. This will make it easier to choose a camera and help you to understand why you might want to have a couple of cameras in your shooting arsenal.
Then it's time to take to the field and examine the rest of the factors that influence the quality of your photographs, including light metering, focus, composition, and flash. Ben also introduces techniques for shooting portraits and shows what you can do with an image editor in post. Last but not least, he'll provide a roadmap for learning more with the lynda.com extensive library of photography training. The path to becoming a better photographer begins with the first step. Start here!
- Exploring cameras and lenses
- Understanding media
- Controlling exposure
- Composing with autofocus
- Shooting portraits
- Understanding form and geometry
- Exporting and editing digital images