Going Digital in a Digital World
A digital camera (or digicam) is a camera that encodes digital images and videos digitally and stores them for later reproduction. Most cameras sold today are digital, and digital cameras are incorporated into many devices ranging from PDAs and mobile phones (called camera phones) to vehicles.
Both digital and film cameras use the same optical system-a lens with a variable diaphragm to focus light onto an image pickup device. The diaphragm and shutter admit the correct amount of light to the imager, just as with film but the image pickup device is electronic (image sensor) rather than chemical. However, unlike film cameras, digital cameras can display images on a screen immediately after being recorded, and store and delete images from memory. Many digital cameras can also record moving videos with sound. Some digital cameras can crop and stitch pictures and perform other elementary image editing.
Digital images are often better than film images. There are many reasons for going digital.
The real reason to switch: once captured, digital photographs are already in a format that makes them incredibly easy to share and use.
For example, you can insert digital photographs into word processing documents, print them at a kiosk, send them by e-mail to friends, or post them on a Web site where anyone in the world can see them. With most cameras, you can immediately see your images on a small LCD monitor on the back of the camera, or you can connect the camera to a TV and show them as a slide show. Some cameras can even be connected to a telescope or microscope to display dramatically enlarged images on a large-screen TV. It is these abilities to instantly share photos that make digital photography so attractive.
If you are considering going digital, here are a few more reasons to get even more serious.
- saves you money in the end since you do not have to buy rolls of film and pay for their development and printing.
- It saves you time because you do not have to make two trips to the store to drop off and then pick up your pictures (although you can do this with the memory card).
- Digital cameras instantly show you how your pictures look so you will no longer have those disappointments a day or two later when your film is developed.
- You can view images before they are printed and if you do not like what you see, edit them to perfection or save money by deleting or not printing them.
- Digital photography does not use the toxic chemicals that often end up flowing down the drain and into our streams, rivers, and lakes.
- No more waiting to finish a roll before having it processed. (Or wasting unexposed film when you cannot wait.)
- Many digital cameras are able to capture not only still photographs, but also sound and even video—they are as much multimedia recorders as they are cameras.
- You can use a photo-editing program to improve or alter digital images. For example, you can crop them, remove red-eye, change colors or contrast, and even add and delete elements. It is like having a darkroom with the lights on and without the chemicals.
- The big difference between traditional film cameras and digital cameras is how they capture the image. Instead of film, digital cameras use a solid-state device called an image sensor. In some digital cameras, the image sensor is a charge-coupled device (CCD), while in others it is a CMOS sensor. Both types can give very good results. On the surface of these fingernail-sized silicon chips are millions of photosensitive diodes, each of which captures a single pixel in the photograph to be.
It is All Black and White After All
- It may be surprising, but pixels on an image sensor only capture brightness, not color. They record the grey scale—a series of tones ranging from pure white to pure black. How the camera creates a color image from the brightness recorded by each pixel is an interesting story with its roots in the distant past.
- When photography was first invented in the 1840s, it could only record black and white images. The search for color was a long and arduous process, and a lot of hand colouring went on in the interim.
- One major breakthrough was James Clerk Maxwell’s 1860 discovery that colour photographs could be created using black and white film and red, blue, and green filters.
- Colors in a photographic image are usually based on the three primary colors red, green, and blue (RGB). This is called the additive color system because when the three colors are combined in equal amounts, they form white. This RGB system is used whenever light is projected to form colors as it is on the display monitor (or in your eye).
- Another color system uses cyan, magenta, yellow and black (CMYK) to create colors. This system is used in a few sensors and almost all printers since it is the color system used with reflected light.
Going Digital – There’s a Computer in Your Camera
- Each time you take a picture millions of calculations have to be made in just a few seconds. It is these calculations that make it possible for the camera to interpolate, preview, capture, compress, filter, store, transfer, and display the image. All of these calculations are performed in the camera by an image processor that is similar to the one in your desktop computer, but dedicated to this single task. How well your processor performs its functions is critical to the quality of your images but it is hard to evaluate advertising claims about these devices. The proof is in the pictures.
- Cameras with the latest programmable digital media processors can perform functions that camera companies program them for. Currently these functions include in-camera photo editing and special effects such as red-eye removal, image enhancement, picture borders, stitching together panoramas, removing blur caused by camera shake, and much more.
A New Direction
- As camera resolutions have improved, most people are satisfied with the quality and sharpness of their prints. For this reason, the marketing battle, especially in the point-and-shoot or pocket camera categories is now all about features.
- Since digital cameras are basically computers, companies can program them to do all sorts of things that older, mechanical cameras could never do. They can identify faces in a scene to focus on, detect and eliminate red-eye, and let you adjust colors and tones in your images
- When you read about features ask yourself how often you would really use them and how much control you want to turn over to your camera.
When considering features, keep in mind that most of the great images in the history of photography were taken using cameras that only let you control focus, the aperture, and the shutter speed.
It is the immediacy and flexibility of digital photography that has made it so popular.It is this new freedom that makes it possible to explore creative photography.
Hand the camera to the kids, take weird and unusual angles, shoot without looking through the viewfinder, and ignore all previously held conceptions about how to take photographs. You may be surprised at the photos you get if you exploit this new era of uninhibited shooting.
The3 Steps of Digital Photography
To understand how the camera fits in with other parts of the digital workflow, it helps to understand the three basic steps involved in creating and using digital photographs—capturing, editing, and sharing.
Step 1. Capturing Photographs
The first step in digital photography is to get a digital image and there is more than one way to do this.
- Digital still cameras capture photographs in a digital format.
- Film cameras capture photographs on slides, negatives, or prints which you can then scan to convert them to digital photographs.
- Video cameras capture images in a video format. You can then use a frame grabber to isolate out individual frames and save them as still images.
- Digital video cameras sometimes are able to capture still images just like a digital still camera. You can also use a video-editing program to extract individual frames from the digital video.
Step 2. Editing Photographs
Once a photograph is in digital form, you can store it on your system and then edit or manipulate it with a photo-editing program such as Photoshop. The things you can do to a digital image are almost endless. In some cases you improve an image by eliminating or reducing its flaws. In other cases, you adjust an image for other purposes, perhaps to make it smaller for e-mailing or posting on a Web site. Finally, you might take an image to a new place, making it something it never was. Here are some ways you can process images:
- Crop the photograph to emphasize the key part.
- Reduce the size of the photograph to make it smaller for posting on the Web or e-mailing.
- Use filters to sharpen it or even make it look like a water colour or oil painting.
- Stitch together multiple frames to create panoramas.
- Merge two images to create a 3D stereo effect or an animated image for display on the Web.
- Change brightness and contrast or expand the tonal range to improve the image.
- Cut and paste parts of one image into another to create a photo-montage.
- Convert the photograph to another format.
Step 3. Sharing Photographs
Once an image is the way you want it, you will find that there are lots of ways to display and share it.
- Print the image on a colour printer.
- Insert the photograph into a word processing or desktop publishing document.
- Post the photograph on a photo sharing Web site or a blog.
- E-mail the photograph to friends or family members.
- Send the photo to a service on the Web for prints, or to have the images printed as a bound book or onto T-shirts, posters, key rings, custom mouse pads, even cakes and cookies.
- Store the photograph on your system for later use.
- Create slide shows that play on a DVD player connected to the TV or a DVD drive in a computer.
Choosing a Digital Camera
There are thousands of different models and styles of digital cameras to choose from.
You are often trading off size versus features.
- Pocket-sized cameras usually do not have as many features as larger cameras, but they are much more convenient.
- Point and shoot cameras usually have fewer controls than other digital cameras and many fit into your pocket;you are more likely to have it when you need it.
- Camera phone quality is improving rapidly with 16 Megapixel models already available in some parts of the world.
- Single-use cameras take surprisingly good pictures and some even have a monitor on which you can review your results.
- Fixed lens cameras often have great zoom lenses and capture large images.
- High-end fixed lens cameras usually have a zoom lens and many of the exposure and focus controls found on SLR cameras.
- One of the most popular camera types among professionals and serious amateurs is the single-lens reflex, better known as a digital SLR. These cameras are expensive but have certain advantages over other camera types:
- You can change lenses.
- You see the scene through the lens so what you see is what you get. (Fixed lens cameras with electronic viewfinders differ from SLRs in that they don’t use a movable mirror to bounce light into the viewfinder).
- You can select from a large variety of accessories, including powerful flash units.
- Rangefinder cameras such as the Leica dominated photojournalism and fine arts photography for decades. They were quiet, small, and their large, bright viewfinders made it easy to focus and compose images.
- Camera size
When it comes to digital cameras, size doesn’t matters much as you think. Small pocket cameras can take images that are as good as those taken by larger cameras. The only difference is they usually have fewer features and lower resolution.
- Video cameras often have the ability to capture still images. The images are smaller than those captured by many digital still cameras, but it’s nice to have this option when you are videoing an event. As you’ll see, most digital cameras also have a movie mode that lets you capture short video clips. The secret to interesting movies for most of us is to keep them short. Short, one minute or so videos can capture highlights and be shared by e-mail or by posting them on popular sites.