A still camera that records images in digital form. Unlike traditional film cameras that record a light image on film (analog), digital cameras record discrete numbers for storage on a flash memory card or optical disc. As with all digital devices, there is a fixed, maximum resolution and number of colors that can be represented. Images are transferred to the computer with a USB cable, a memory card or wireless. Digital video cameras (see camcorder) also use FireWire.
Digital Advantages
There are three distinct advantages of digital cameras over their analog counterparts. First, you can review the finished image immediately and erase the others. Second, you can take and print one picture without waiting to develop an entire roll of film. Finally, memory cards, the storage mechanism most widely used for "digital film," are reusable over and over.
Chips: The Camera's Film
Digital cameras record color images as intensities of red, green and blue, which are stored as variable (analog) charges on a CCD or CMOS image sensor chip. The charges are converted to digital and stored in flash memory chips on a memory card such as CompactFlash, SD or Memory Stick. Some still cameras use optical discs for storage instead of flash memory, and video cameras use tape, optical discs and hard disks (see DV).
The size of the CCD or CMOS chip determines the picture's resolution, but the analog-to-digital converter (ADC), which converts the charges to digital data, determines the color depth. In 2002, Foveon introduced a breakthrough in color accuracy with its X3 CMOS chip (see Bayer pattern and X3).
Digital video cameras use the same image sensing methods as still cameras, but in addition to storing the images digitally, they output NTSC video for playback on any TV. See flash memory, photo editor, photo scanner, X3, digital camera record modes and DSLR.
Major Features
Following are the major features and some caveats of digital cameras.
Resolution in Megapixels
The number of pixels determines the maximum size of the resulting image and its sharpness, especially when printed. The higher the resolution to start, the better the results. You can easily reduce a high-resolution image to low resolution in the computer, but you cannot go from low to high with great results. The bottom line: know the final destination of your images. Following is a guide to the amount of megapixels required in the camera:
User Interface
Nothing is more critical to photographers than the feel of their cameras. Because it uses a combination of physical buttons and on-screen menus, a digital camera's interface can be more daunting than that of a desktop computer. At the very least, spend some time in the store reviewing the basics. If at all possible, borrow the camera from a friend for a photo session.
Optical and Electronics Quality
As it has in film cameras for nearly two centuries, the optical quality of the camera's lens greatly contributes to the resulting picture quality. In addition, the color and geometric accuracy of the pixels in the CCD or CMOS sensor combined with the camera's internal processing circuits can make all the difference. Specifications on paper are not enough, and reviews from sources such as photographic Web sites are very informative.
Optical vs. Digital (Interpolated) Zoom
The optical zoom is the real resolution of the lenses. The digital zoom is an interpolated resolution computed by software. The higher the optical number, the better. A 10x optical is far superior to a 10x digital (see optical zoom).
Storage Media
There are several types of flash memory cards used for "digital film," but no matter which type the camera uses, the one that comes with the camera is typically undersized. Plan on purchasing a larger one when you buy the camera (see flash memory).
Data Transfer
Digital cameras come with a USB cable for transfer directly to the computer, and many computers come with one or more memory card slots. Printers may also come with card slots, allowing you to print your photos without using the computer at all. Wireless (Wi-Fi) transmission is also available on some cameras.
Battery Duration
Digital cameras use either rechargeable or standard AA batteries. It can take an hour or more to recharge a battery, so having an extra, fully charged battery is recommended. AA batteries can be purchased anywhere, and rechargeable AA's can also be used.
Interchangeable Lenses
Digital SLR (single lens reflex) cameras are the digital counterparts of their analog predecessors and may use the same removable lenses that you already own. However, the sensor chip may be smaller in size than a 35mm frame, which means your 28mm wide angle lens might function like a 42mm lens. Lenses made specifically for the digital SLR do not have this focal length mismatch. See DSLR.
LCD Screen and Viewfinder
Small, point-and-shoot cameras use a "live preview" LCD screen to take pictures and display the stored images. Digital SLRs have a traditional viewfinder that you press your eye against for taking pictures and mostly use the LCD as a monitor to show the results. The larger the LCD screen, the more the camera serves as a convenient playback device.
The eyepiece viewfinder has always been an effective method for taking pictures because pressing the camera against the eye actually steadies it. It also helps the photographer frame the picture by eliminating everything outside the viewing area. In addition, the LCD can sometimes be so washed out in a bright sunny day that it becomes difficult to take a picture. As a result, some point-and-shoot cameras also include a viewfinder. See viewfinder.
Digital Camera
Behind the lens, a CCD or CMOS image sensor chip picks up the image as variable (analog) charges that are turned into digital by an analog-to-digital circuit (see A/D converter). A DSP chip adjusts contrast and detail and compresses the digital data for storage.
Camera and "Film"
A classic now, the DC50 was one of the first digital cameras from the venerable Kodak company. Holding 24 images in internal memory, it used flash disks for more storage. (Image courtesy of SanDisk Corporation.)
Photo Printer
FARGO made one of the first printers designed for 4x6\" photographic prints. The 1995 introduction of the $595 FARGO FotoFUN! was a breakthrough price for a dye sublimation printer. (Image courtesy of FARGO Electronics, Inc.)
CYCOLOR Printer
CYCOLOR printers are different than other digital printers, because the imaging is done inside the paper, which is sensitive to light (see CYCOLOR). (Image courtesy of Cycolor, Inc.).
Print Via the Web
Photo printing companies such as Photoworks and Kodak EasyShare Gallery (formerly Ofoto) let you upload your digital pictures to their Web sites so they can be previewed by family and friends from any Internet connection. Clicking on a thumbnail (top) displays a larger, low-res image (bottom). High-resolution prints can be ordered by anyone. Undeveloped analog film can also be sent to the companies for processing. (Images courtesy of Jim and Karen Clayton.)
Digital Advantages
There are three distinct advantages of digital cameras over their analog counterparts. First, you can review the finished image immediately and erase the others. Second, you can take and print one picture without waiting to develop an entire roll of film. Finally, memory cards, the storage mechanism most widely used for "digital film," are reusable over and over.
Chips: The Camera's Film
Digital cameras record color images as intensities of red, green and blue, which are stored as variable (analog) charges on a CCD or CMOS image sensor chip. The charges are converted to digital and stored in flash memory chips on a memory card such as CompactFlash, SD or Memory Stick. Some still cameras use optical discs for storage instead of flash memory, and video cameras use tape, optical discs and hard disks (see DV).
The size of the CCD or CMOS chip determines the picture's resolution, but the analog-to-digital converter (ADC), which converts the charges to digital data, determines the color depth. In 2002, Foveon introduced a breakthrough in color accuracy with its X3 CMOS chip (see Bayer pattern and X3).
Digital video cameras use the same image sensing methods as still cameras, but in addition to storing the images digitally, they output NTSC video for playback on any TV. See flash memory, photo editor, photo scanner, X3, digital camera record modes and DSLR.
Major Features
Following are the major features and some caveats of digital cameras.
Resolution in Megapixels
The number of pixels determines the maximum size of the resulting image and its sharpness, especially when printed. The higher the resolution to start, the better the results. You can easily reduce a high-resolution image to low resolution in the computer, but you cannot go from low to high with great results. The bottom line: know the final destination of your images. Following is a guide to the amount of megapixels required in the camera:
Destination Minimum Megapixels
Web site images 1 MP
Computer screen 2 MP
3x5 and 4x6 prints 2 MP
8x10 print 4 MP
11x14 print 6 MP
16x20 print 12 MP
User Interface
Nothing is more critical to photographers than the feel of their cameras. Because it uses a combination of physical buttons and on-screen menus, a digital camera's interface can be more daunting than that of a desktop computer. At the very least, spend some time in the store reviewing the basics. If at all possible, borrow the camera from a friend for a photo session.
Optical and Electronics Quality
As it has in film cameras for nearly two centuries, the optical quality of the camera's lens greatly contributes to the resulting picture quality. In addition, the color and geometric accuracy of the pixels in the CCD or CMOS sensor combined with the camera's internal processing circuits can make all the difference. Specifications on paper are not enough, and reviews from sources such as photographic Web sites are very informative.
Optical vs. Digital (Interpolated) Zoom
The optical zoom is the real resolution of the lenses. The digital zoom is an interpolated resolution computed by software. The higher the optical number, the better. A 10x optical is far superior to a 10x digital (see optical zoom).
Storage Media
There are several types of flash memory cards used for "digital film," but no matter which type the camera uses, the one that comes with the camera is typically undersized. Plan on purchasing a larger one when you buy the camera (see flash memory).
Data Transfer
Digital cameras come with a USB cable for transfer directly to the computer, and many computers come with one or more memory card slots. Printers may also come with card slots, allowing you to print your photos without using the computer at all. Wireless (Wi-Fi) transmission is also available on some cameras.
Battery Duration
Digital cameras use either rechargeable or standard AA batteries. It can take an hour or more to recharge a battery, so having an extra, fully charged battery is recommended. AA batteries can be purchased anywhere, and rechargeable AA's can also be used.
Interchangeable Lenses
Digital SLR (single lens reflex) cameras are the digital counterparts of their analog predecessors and may use the same removable lenses that you already own. However, the sensor chip may be smaller in size than a 35mm frame, which means your 28mm wide angle lens might function like a 42mm lens. Lenses made specifically for the digital SLR do not have this focal length mismatch. See DSLR.
LCD Screen and Viewfinder
Small, point-and-shoot cameras use a "live preview" LCD screen to take pictures and display the stored images. Digital SLRs have a traditional viewfinder that you press your eye against for taking pictures and mostly use the LCD as a monitor to show the results. The larger the LCD screen, the more the camera serves as a convenient playback device.
The eyepiece viewfinder has always been an effective method for taking pictures because pressing the camera against the eye actually steadies it. It also helps the photographer frame the picture by eliminating everything outside the viewing area. In addition, the LCD can sometimes be so washed out in a bright sunny day that it becomes difficult to take a picture. As a result, some point-and-shoot cameras also include a viewfinder. See viewfinder.
Digital Camera
Behind the lens, a CCD or CMOS image sensor chip picks up the image as variable (analog) charges that are turned into digital by an analog-to-digital circuit (see A/D converter). A DSP chip adjusts contrast and detail and compresses the digital data for storage.
Camera and "Film"
A classic now, the DC50 was one of the first digital cameras from the venerable Kodak company. Holding 24 images in internal memory, it used flash disks for more storage. (Image courtesy of SanDisk Corporation.)
Photo Printer
FARGO made one of the first printers designed for 4x6\" photographic prints. The 1995 introduction of the $595 FARGO FotoFUN! was a breakthrough price for a dye sublimation printer. (Image courtesy of FARGO Electronics, Inc.)
CYCOLOR Printer
CYCOLOR printers are different than other digital printers, because the imaging is done inside the paper, which is sensitive to light (see CYCOLOR). (Image courtesy of Cycolor, Inc.).
Print Via the Web
Photo printing companies such as Photoworks and Kodak EasyShare Gallery (formerly Ofoto) let you upload your digital pictures to their Web sites so they can be previewed by family and friends from any Internet connection. Clicking on a thumbnail (top) displays a larger, low-res image (bottom). High-resolution prints can be ordered by anyone. Undeveloped analog film can also be sent to the companies for processing. (Images courtesy of Jim and Karen Clayton.)
 | Reproduced with permission from Computer Desktop Encyclopedia. Copyright (c) 1981-2009 The Computer Language Company Inc. All rights reserved. |
Additional Resources
- Canon releases EOS 7D firmware update
- After it was discovered that the Canon EOS 7D has a ghosting glitch, the company has released a firmware update to correct the problem. EOS 7D owners can download the 7D Firmware Update Version 1.1.0 at Canon's USA website. The update promises the following fix: Corrects...
- Blog posts 2009-11-06
- Zoom Q3 camcorder--photos
- Take a closer look at the Zoom Q3, a solid state digital video camera with an emphasis on professional sound quality. by CNET News.com
- Image galleries 2009-11-05
- HoudahGeo 2.3.5 (Mac)
- HoudahGeo is a one-stop geocoding application for the Mac. With HoudahGeo you may "pin" photos to the locations where they were taken. The thus created information may be exported to EXIF tags as well as to Google Earth KML files. Such a file allows for browsing your photos within Google...
- Software downloads 2009-11-05
- Spyglass for iPhone 1.1 (Mobile)
- Spyglass for iPhone is a digital and fun augmented reality tool. It turns an iPhone into a digital spyglass with heads-up display that in real-time shows you a compass, GPS information and a horizon tilt right over the live feed from the built-in camera. Looking through the Spyglass for iPhone...
- Software downloads 2009-11-05
- PTPdrive 1.0 (Windows)
- PTPdrive integrates a digital camera operating in PTP/MTP mode into the Windows by mapping it to a local drive letter. Pictures can be accessed by simply opening them from a drive letter--there is no need to run a separate application to transfer the pictures anymore. PTPdrive enables any Windows application...
- Software downloads 2009-11-04
- Video Capture Master 7.1.0.198 (Windows)
- Do you want to grab real-time video or image? Video Capture Master is a useful application that enables you to record video and image from video devices in real time. Video Capture Master is a hot piece of application designed to suit your needs. With it you can effortlessly record...
- Software downloads 2009-11-04
- myDiary 1.4 (Mac)
- myDiary is a clear and easy-to-use 'journaling application' with some cutting-edge functions like an integrated video diary, image and file management. Self evident that all entries are stored encrypted and that it all can be protected with a password. Today's diaries aren't just made out of text. Thus myDiary...
- Software downloads 2009-11-04
- Sony Ericsson Equinox TM717 - carbon black (T-Mobile)
- Photo gallery:Sony Ericsson Equinox TM717The Sony Ericsson Equinox is the first phone from the manufacturer to land at T-Mobile since the TM506. In many ways the Equinox is a fitting successor; like the TM506 it has a thin flip phone design and it sports a similar feature set that includes...
- Product reviews 2009-11-03
- Geotagalog 1.5.2 (Mac)
- If you have a handheld GPS receiver, Geotagalog will let you take full advantage of the Places feature in iPhoto '09 with any digital camera supported by OS X. Geotagalog uses our advanced geotagging technology to combine a GPX tracklog file with the pictures on your camera, in a straightforward...
- Software downloads 2009-11-03
- Micro Video Capture 7.0.0.658 (Windows)
- With Micro Video Capture, you can record video and image from Webcam, TV tuner card, digital camera and other capture devices in real time, and all captured video files can be saved as AVI format by using any compression codec. What's more, it enables you to set each capture device's...
- Software downloads 2009-11-03
- What to look for in a Mini-HD camcorder
- Couple of thingsI have a Memorex small HD camcorder, looks similar to the Flip, bought cheap & works OK.2 annoyances: first, the digital "zoom" can't change while it is recording -- i.e., you have to set the zoom while NOT recording, then hit the record button. Not sure how...
- Discussion threads 2009-11-02
- Holiday Gift Guide 2009: Digital SLR camera accessories
- OK shootLoved the picture of the camera holster!Presumably this Tombstone resident was going for a shoot at the OK Corral?HolsterBlackrapid's R Strap is another way to keep a camera or two to hand.The holster here looks to reduce the camera's tendency to bounce around as you're moving. If you...
- Discussion threads 2009-11-02
- Visual Photo Time Stamp 2.1.3 (Windows)
- For most of today's digital cameras the photos are saved in JPG files. The date and time at which a photo is taken are stored along with the image in so called EXIF format. Such date and time information can be viewed on a PC once the JPG files are...
- Software downloads 2009-11-02
- Holiday Gift Guide 2009: Digital SLR camera accessories
- There's probably nothing a digital camera enthusiast likes better than gear and gadgets, which makes shopping for your favorite shutterbug a cinch. If you're looking for a great holiday gift for someone who already has his or her dSLR of choice, one of these dSLR camera accessories -- ranging...
- Blog posts 2009-11-01
- Recuva 1.32.444 (Windows)
- Recuva (pronounced "recover") is a freeware Windows utility to restore files that have been accidentally deleted from your computer. This includes files emptied from the Recycle bin as well as images and other files that have been deleted by user error from digital camera memory cards or MP3 players. It...
- Software downloads 2009-10-31
- How to take clear pictures at night
- With Halloween just a day away, you might be thinking about shooting photos at parades or your kids trick-or-treating. But most of those activities are at night, which could hinder photographers. But there are a few steps that can help you take clear, crisp photos at...
- Blog posts 2009-10-30
- A-PDF Image to PDF 2.7.4 (Windows)
- A-PDF Image to PDF is an utility that lets you convert photos, drawings, scans and faxes into Acrobat PDF documents. Its features include supporting almost all of image formats includes TIFF, JPEG, GIF, BMP, PNG and ICO, even acquiring images from scanner or digital camera directly. It also is able...
- Software downloads 2009-10-30
- How to capture vibrant fall foliage with your digital camera
- Warming filter or adjusting white balance...Using a warming filter or adjusting the white balance to boost warm colors will also enhance the Fall colors.RE: How to capture vibrant fall foliage with your digital cameraUnderexposing by 1/3 F stop usually gives greater color saturationRE: How to capture vibrant fall foliage with...
- Discussion threads 2009-10-29
- How to capture vibrant fall foliage with your digital camera
- Fall (or autumn, for many of you) is my favorite season of the year, particularly because of the crisp weather and beautiful falling leaves. Capturing the vibrancy of the foliage can easily be done with either a pocket camera or digital SLR. Here are five tips...
- Blog posts 2009-10-29
- How to find a quality film scanner
- ConfusedV500: 6400dpiV700: scan speed(?) from 300 to 600dpi8800F: maximum resolution of 4800?9600Am I ignorant or is this full of errors and inconsistencies in data/spec presentations?More quality film scannersCertainly there are many more than just those three. Microtek, for instance, currently offers five models, all of which support transparencies up...
- Discussion threads 2009-10-28
Neighboring Terms
Premier Vendor Content Whitepapers, webcasts & resources from our Power Center Sponsors
SmartPlanet
- Thought-provoking progressive ideas on diverse topics that intersect with technology, business, and life, and matter to the world at large. Visit SmartPlanet
- More from IBM
-
- Can your business work smarter? Learn more about Lotus Symphony
- Learn how to work smarter and optimize cost using the IBM Smart SOA approach Download the eBook
- Smarter ways to make smarter products Read the brief from IBM
