44 PART 1 GETTING TO KNOW DIGITAL CAMERAS
PUTa digital camera next to a camera that still uses film—if you can find a new camera that still uses film. How
are they different? Some digital cameras are dead ringers for the 35mm SLR—single-lens reflex—that dominated
photography for professionals as well as everyman for more than half a century. Nevertheless, a lot of the digital
cameras are smaller than any film cameras you’ll see outside of a spy movie. A few have some bizarre touches.
One twists so that half the camera is at a right angle to rest of it. Some Kodaks have two lenses. Other digitals have
abandoned the traditional boxy shape and taken on the forms of credit cards or a child’s pencil holder. Still others
hide within phones, watches, and binoculars.
However odd their housings might be, digital cameras externally retain much in common with their film ancestors.
They both have lenses, some sort of viewfinders to peer through, and similar assortments of buttons and knobs.
The important difference between film and digital cameras is not in their shapes, but what the cameras hide inside.
Take off the back of a film camera, and you’ll see a couple of slots at one end where you insert your canister of film
and an empty spool on the other end to take up the roll of film as each frame is exposed. Between them, directly
inline with the lens, is the pressure plate. It provides a smooth, flat surface for the film to rest against. In front of the
pressure plate is a shutter made of cloth or metal sheets that open quickly to expose the film and then close just as
quickly so the film doesn’t get too much light. (Some cameras have shutters in the lens, but you can forget that fact
without any ill consequences.)
Take a digital camera and open up the back—you can’t! There is no way to open it and see what’s inside.
That’s what this book is for, to show you what you ordinarily can’t see on your own. You’ll see in this part that some
components of the film camera have survived in digital equipment, most notably lenses and shutters. And you get to
look inside digital cameras where much of the apparatus common to film cameras—and the film itself—have been
replaced by microchips packed with transistors, electronic switches smaller than dust motes.
Two types of microchips are particularly important, and we’ll examine what they do in more detail later on in the
book. One is a microprocessor similar to the microchips in computers, wireless phones, and just about anything else
these days that runs on electricity—the type computer writers like to refer to as the “brains” controlling an apparatus
or a procedure. Some cameras have more than one microprocessor. One “brain” might apply special effects to
I always thought of photography as a naughty thing to do—that was one of
my favorite things about it, and when I first did it, I felt very perverse.
Diane Arbus