Chapter One
The Differences between Digital and Film Photography
At first glance, digital cameras pass the "duck" test with flying colors. That is, if it looks, waddles, and quacks like a duck, it must be a duck.
To the casual observer, there's little or no difference between a digital camera and a film camera. Both have a lens, shutter, diaphragm, and viewfinder. Both take pictures when you aim them at the subject and pressing a shutter button. And to the untrained eye, both produce almost-identical-looking photographs that can be pasted in albums, mounted on refrigerator doors, used in business communications or hung in art galleries.
However, as much as digital cameras and film cameras are alike, they are also as radically different as a jet plane is from a helicopter, or a dog is from a tiger.
Some differences are obvious. Film is a chemical-based process, while digital is an all-electronic medium. Digital can provide instant feedback on your just-shot images, while you have to wait to see your film photos. Other dissimilarities become apparent only after you start using a digital camera.
The many significant and subtle differences between the two technologies can and will affect the way you take pictures. In this chapter, we'll examine how both film and digital work their magic in recording photographic images and how using digital cameras impact upon the choices you must make.
Why Film?
Film has lasted over a century and a half as the world's most popular medium for capturing and preserving visual memories for lots of compelling reasons:
* It's cheap-A film cassette or roll costs only a few bucks.
* It's ubiquitous-You usually can buy film at any convenience store, drugstore, or even newsstand anywhere in the world. And you can get it processed within an hour at almost any mall or drugstore.
* It's portable-Film is small, light, and travels well in a pocket or purse.
* It stores well-Negatives and transparencies fit very nicely in folders, sleeves, loose-leaf binders, shoeboxes, drawers, and so on.
* It's instantly viewable-All you have to do is hold a developed negative or transparency up to a light, and you can see the image. You don't need special equipment to view what you have.
* It's easy-Single-use cameras (SUC) (also called film-in-a-box) are instantly ready to shoot and require no learning or shooting skills. Just advance the film and press the shutter. No wonder 60 billion SUCs were sold last year. * It lasts-If stored properly, that black-and-white negative shot by your great-great-grandfather will probably yield a print almost as good as when it was originally taken.
* It's versatile-There's an emulsion for just about any need or preference-color, black and white, fine grain, high speed, infrared, and so on. * It's good-35mm fine-grain film can be blown up to poster size and maintain great color, razor sharpness, beautiful tonality, and image fidelity.
Film photography is a mature technology that has been giving us satisfaction and pleasure for generations. Is there anything more wondrous and representative of our culture than a shoebox of old fading and foxed photos of family memories? And the quality of film photos can't be beat. But film does have its disadvantages:
* Though it has fairly wide temperature latitude, film degrades quickly in extreme heat (as in a car's glove compartment in summer) and loses sensitivity in extreme cold.
* Undeveloped film must be kept in lightproof boxes or containers before and after shooting-one brief accidental exposure to the sun, and it's toast.
* Unexposed film has a practical life expectancy of 2-4 years, depending upon the emulsion and how well or badly it had been stored. Outdated or short-dated film gradually loses both sensitivity and color fidelity.
* It must be processed with environmentally hostile chemicals in a darkroom or by a photo lab, a precise, time-consuming, and costly procedure. If the temperature is too warm or too cold, the chemicals are not mixed in the correct manner, or the film is immersed for too short or too long a time, the film can be irreparably damaged, and the photos on it can be permanently lost.
* Developed color film degrades and deteriorates over time, to the point where it may be almost unusable after only a few years.
* If not handled and stored properly, film is prone to scratches, gouges, and dust, all of which adversely affect image quality.
Why Digital?
Digital photography is a new and growing technology that most observers predict will replace film in short order. Here are some of digital's numerous advantages:
* It's economical-You'll never again spend another nickel on film or processing (known in the industry as "consumables"), since your digital camera's built-in electronic memory or external memory cards can be used and reused thousands of times.
* It's immediate-With a digital camera, you can take a shot and instantly review it in the camera's LCD viewfinder. If your subject blinked or is out of focus, if you don't like the composition, or if the picture is too dark or light, you can then simply erase the picture at the push of a button and shoot over.
* It's versatile-Many digital cameras do more than take a still photograph. Your digital camera may allow you to record video or audio, create panoramas, stamp time/date and GPS coordinates on your pictures, and check world time. And if you have a camera cell phone, you can even call your friends between snapshots and quickly send the pictures to them.
* It's contemporary-In this day and age, the vast majority of our communications are digital. This covers everything from email to Web pages, business presentations to recordkeeping. Even material that ends up printed starts out digitally in our computers, where it is created, assembled, edited, and saved. If you want pictures to be part of your communications ("a picture is worth a thousand words"), then you'll need digital photos.
* It records its own history-A digital file of a photo can contain much more than a picture. Attached to that file can be all kinds of valuable information (called metadata) about where, how, and when a photo was taken. That data can be appended or edited, used to help identify and organize files, and in some situations, even be offered as legal evidence. (For more information on metadata, see Chapters 5 and 21.)
* It's permanent-Stored correctly on a high-quality CD or DVD, a digital photograph will never fade, fox, or lose data, and can last over a century.
* It gives pro-like control-Digital photography offers the average user the kind of control over the creation, editing, and use of his photos that used to be the domain of only expert photographers.
* It's fun-Beyond the immediate feedback and ability to display them right away on any computer screen or television, you can play with digital photos, change them artistically or humorously, remove your wrinkles, or add a mustache, try a new hair color, or paste yourself onto a Hawaiian beach. Using photo-editing software in your computer, you are limited only by your imagination. (See Chapter 18.)
As you read this book, you'll discover and master many other advantages of digital photography. But you'll also need to be aware that that digital does have its disadvantages, too:
* Digital cameras can be pricy, certainly more expensive than comparable film cameras. * Digital cameras can be complicated. Except for the least expensive point-and-shoot models, most digital cameras offer a bewildering array of choices and options that can intimidate many users.
* Many digital cameras aren't as fast or sure shooting as film cameras. With many models, it takes a few seconds for the camera to power up before you can take the first shot. You may also encounter a frustrating, unavoidable delay between the time when you press the shutter and when you actually take the picture, so you may lose the shot if the subject moves in the interim. And because it's necessary to process and save the just-captured image, it can take anywhere from a second to a half-minute before your camera is ready to shoot again. (See Chapter 3 for tips on dealing with and reducing shooting delays.)
* Press the wrong button, and you could accidentally delete one, or even all, of your pictures. * Connecting your digital camera to your computer can be a difficult, intimidating job. (See Chapter 17 for advice on how to get images into your computer.)
* Digital cameras may eat up batteries at an alarming rate. (See Chapter 4 for tips on buying batteries and Chapter 11 for advice on how to save on batteries.)
* The days of stumbling across a stored shoebox of memories and just sitting on the floor looking at photos of your family and friends will eventually fade away. Unless you make prints of your digital photos, you will need some sort of digital device to view them. That's why an archiving plan is important. And, of course, why those photos that are most precious to you should be printed. (Please see Chapter 20 on printing and Chapter 21 to learn about archiving.)
Still, the advantages of digital photography far outweigh the disadvantages. Besides, the genie is out of the bottle. Digital photography is here to stay. Film will soon be as foreign to the average person as old-fashioned rotary dial phones, and as obsolete as buggy whips and coal scuttles.
All Cameras Are Alike ...
The word photography literally means "writing with light." Photography as an art and a science has existed and evolved for about 170 years, give or take. It had a hundred births, in the cramped closets and kitchens of inventors and innovators who labored in absolute darkness, coating paper, metal, and glass surfaces with photosensitive silver salts, exposing them inside light-proof wooden boxes affixed with lenses appropriated and adapted from telescopes and eyeglasses, and then immersing them into witches' brews of caustic chemicals to develop and fix those images permanently. Although the process has been vastly improved and greatly refined through the years, film-based photography is still essentially the same as it was back in the 1830s.
At its most basic, photography requires a device that creates a photograph (see Figure 1-1). We call that device a camera, which is a box that captures the light reflected from a scene, person, or object and converts it into a tangible representation of that light, that is, a picture.
To do this, most cameras typically have the following components:
* A lens for directing and focusing the light into the camera
* A diaphragm for regulating the amount of light allowed to pass into the camera, as well as controlling the depth of field
* A shutter for controlling the duration of the light passing through the camera
* A button or shutter release that tells the camera when to take the picture
* A photosensitive element (film or an electronic image sensor) to record the photo
* All contained in a light-proof box
In addition, most modern cameras also have:
* A window (or viewfinder) of some sort for the photographer to preview what the camera lens sees
* A photoelectric light meter for calculating exposure settings
* A built-in electronic flash or interface for connecting an external strobelight
* An electronic sensor to regulate flash intensity and duration for proper exposure
How a Film CameraWorks
All of us have been using film cameras our entire lives, but most of the time it's been like driving our cars, with no thought as to what is really happening under the hood. To understand digital photography, it's important to consider its antecedents in film photography. Then, it will be easier to recognize the differences and similarities between the two technologies, which will lead to more easily and fully mastering the new world of digital photography.
Film
Of course, the most vital part of any film camera is film. Without it, the camera is simply an expensive, useless mechanical toy.
Film is any medium or material (usually a flexible plastic Mylar base) coated with photosensitive silver halide crystals. Inside the camera, light passes through the lens and is focused onto the film. When the shutter opens, the film is briefly exposed to light, which causes an immediate chemical reaction: the sensitized silver halide crystals (grain) turn dark, creating a latent image. And where no light strikes, the crystals remain unchanged.
When developed and fixed (in total darkness) through a series of chemical baths, the latent image becomes visible, all reactions cease, the image becomes stable, and the unused (unexposed) silver halide crystals precipitate and are washed away.
What makes film particularly interesting for those of us who want to understand digital photography is that the attributes of both technologies are described in similar or even identical terms:
* Sensitivity to light (which, in film, is rated in ISO numbers)
* Grain, or the size and appearance of the small particles (crystals) that make up the picture
* Resolution, or the degree of sharpness and detail
* Dynamic range, the measure of how much detail the film can capture in the full tonal range, from deep shadows to bright highlights.
Sensitivity, grain, resolution, and dynamic range are closely related because they directly affect each other.
* A particularly sensitive, or high-speed film (that is, one that can be shot in lower-light situations), is somewhat grainer than a lower-sensitivity film.
* The bigger the grain crystals, the lower the image resolution and dynamic range. * The finer the grain, the lower the sensitivity to light, but the wider the dynamic range and more detailed the resolution.
High-speed film (400 ISO and above) is useful for capturing available-light and low-light subjects, sports action, photojournalism, industrial and scientific processes, fidgety kids, and squirming pets.
Continues...
Excerpted from PC Magazine Guide to Digital Photography by Daniel Grotta Sally Wiener Grotta Excerpted by permission.
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