There are many ways of getting your pictures into a digital form that the computer can process. Each has its advantages and disadvantages where it would not be uncommon for one to use many or all of the available options.
The Photo CD format was developed by Kodak as a way to archive photographs. The Photo CD is created during the photo finishing process, where the pictures are scanned with special high-resolution, calibrated equipment. Up to 100 images can be stored on a single CD.
- No additional hardware needed. If you have a traditional film camera, even the one roll throwaways, you can get a Photo CD made. If you have a multimedia compliant computer, you can read Photo CD's with appropriate software which is usually included with either your printer or the computer itself.
- High resolution and quality. Photo CD's support multiple resolutions (up to 2048 x 3072) which allow good quality prints even at 8 X 10 size. The scanning equipment is calibrated to produce consistently high quality results.
- Durable media. In addition to having your original photographs and negatives, the CD itself is a durable storage media which can be easily stored.
- Increased processing cost. There is obviously an extra charge for creating the PhotoCD, it may still be cost-effective depending upon the amount of photographs you do.
- Processing wait. Not all photo finishing processors provide the PhotoCD service. Kodak's website lists the authorized processing centers.
- Inability to edit image on CD. The PhotoCD image is scanned directly from the photo, so what you snapped is what you get. To edit or crop the image requires you to load the picture and edit it with software.
Image scanners can take many forms. The first were hand held devices that were usually black and white only that you dragged across the document you were copying. The width of the scanners generally were around 5 to 6 inches, so for a wider document, the software needed to be intelligent enough to "stitch" the two halves of the image together. Then came the flatbed scanners that looked somewhat like the top part of a copier. They usually used either a SCSI interface or a proprietary manufacturer's interface card. The first color scanners would perform 3 passes of the object; using red, green, and blue lamps. Today's scanners perform the scan in one pass, and many low priced scanners are available that plug into the printer port, although the higher speed units still use SCSI or some other plug in card. There are even scanners for standard 4 x 6 photographs and negatives that can be installed in one of your computer's hard drive bays or sit on top of your computer.
- Scan what you want. You are not limited to scanning photographs, anything that fits on the scanner bed is fair game. You can crop pictures and save memory by scanning only the portion of the object you want. The newer scanners even have sufficient resolution to handle negatives with ease and the software will automatically convert the negative images to the correct colors.
- High resolution. The resolution available rivals the quality of the PhotoCD, again enlargements to 8 X 10 are possible.
- Fairly low cost. Inexpensive scanners have dropped below $100. These invariably use the computer's printer port, limiting the scanning speed.
- Fast turnaround. You can have your pictures developed at the 1 hour photofinishers and have them scanned in a short time later.
- Hardware installation necessary. For the higher speed scanners, a SCSI or a proprietary interface card must be installed in the computer. You therefore need to either be knowledgeable about installing interface cards, or you must pay to have them installed. And there's always a chance of strange hardware conflicts later on. A SCSI scanner will usually be provided with a very short (around 3 feet) interface cable. Longer cables are available but extremely expensive ($75 or so). You therefore must take into account where your computer and scanner are going to be placed. My computer setup is dictated by the fact that the scanner must be on the computer desk, taking up space I (and the cat) would rather have on the desk for other things. For the printer port scanners, you may have the option of plugging your printer into the rear of the scanner. Some scanners, however, do not support the bi-directional interface that many newer printers use to inform the printer driver of its status (out of paper, amount of ink left, other printer diagnostics). You must therefore either exchange the printer and scanner connections by hand as needed, or purchase a printer switch box. But beware here also, many printers cannot be used with a printer switch, you need to consult your printer manufacturer for its compatibility.
- Not instant. Even though you can use the 1 hour photofinisher, that assumes you have an entire roll of film done, or don't mind wasting an unfinished roll of film.
Frame grabbers are devices that accept a video signal like that used on a television from sources like a VCR or camcorder and convert it to digital form. The simplest ones, like Snappy, connect to your printer port and are suitable for single frames. The more expensive devices are interface cards that require installation, but have sufficient speed to enable you to capture full motion video (but that's beyond the scope of this primer, for now at least). Also included in this category are some 'TV on a PC card' devices that allow you to watch TV on your monitor, many of these have video inputs and let you capture video images.
- No wait for processing. If you've taken movies with your camcorder, you can process them as soon as you get to your computer. Its also the best way to get images from TV broadcasts (but keep in mind the copyright laws).
- Low cost?. It depends on your circumstances whether the expense is worth it. If you already have a good quality camcorder (see disadvantages), it may make sense if you don't want to purchase another camera if you're not sure you need it. The low cost grabbers are less expensive than any digital camera.
- Cumbersome. For printer port devices, the same caveats as the scanners apply. You either have to cable swap, or invest in a printer switch. For all of the grabbers there's also the hassle of connecting the video device (camcorder or VCR) to the grabber. Unless you have a laptop at your disposal to carry to your VCR, you're pretty much stuck with using your camcorder. Also finding the right frame on the video tape to capture can be a bit tricky, many camcorders and VCRs have trouble providing stable images when put in their pause mode. Best shots will come when using the camera it its "live" mode, before the image gets to the video tape.
- Lower quality. Remember that the maximum resolution available from a standard video signal is less than a standard VGA screen. What may look OK to you on a TV screen in motion (be it VCR or your camcorder) may not look as good when frame grabbed because the random noise in the picture is more difficult to see at normal speed. And the best shots will come with the higher quality (SVHS or HI-8) camcorders. Lower quality cameras may also suffer from lack of color that can't be compensated for.
Which leads us to the latest development, digital cameras. You can think of them as a camcorder without video tape. They use the same resolution CCD "camera" that camcorders use. Instead of recording the CCD's output onto video tape, they digitize the signal and store it in the camera's memory. Some may look like a standard 35mm camera and take accessory lenses (like zoom and wide angle), or may take an entirely different format since they don't need to worry about handling film. They differ in the way you get the image to the computer, some can put the images on standard 3.5" floppies, others use PCMCIA or Compact Flash RAM cards (allowing hundreds of images to be stored in the camera), or you can connect a cable to your computer's serial port. Some cameras will also allow you to store a few seconds of audio with the picture so you can identify it easier later.
- Near instant photography. Some camera manufacturers also have color printers in their offerings designed to be used with their cameras. This eliminates the computer and allows instant printouts. In any case, there's no waiting for photo processing.
- Save only what you want, erase the rest. Want to try multiple shots of a subject with different light or other conditions. Don't worry about using up film. With cameras that include LCD viewfinders, you can immediately see the results, and if you don't like it, you can erase the picture on the spot.
- Ease of picture transfer. If you have a camera that uses 3.5" floppies, transferring the image to your PC couldn't be simpler, though the number of images that can be stored on an floppy is limited. If your computer can handle PCMCIA or Compact Flash (there are drives available for desktop PC's and nearly all laptops can handle the PCMCIA cards) again, transfer is easy. If you need to use a serial cable, just leave it connected to your PC's serial port and connect to your camera when needed.
- Expense. Digital cameras are still fairly expensive, but the prices are coming down rapidly. Most cameras only have enough on board memory to store 30 - 40 pictures at its lowest quality setting, therefore to store more requires purchasing in most cases a Flash RAM card.
- Resolution less than traditional photography. Since the cameras use the same CCD element that the camcorders use, your resolution is usually limited to 640 x 480 or up to 756 x 567. This is much less than the 2048 x 3072 offered by the PhotoCD and by Image Scanners. So the largest size print you would want to attempt would be on a 4 x 6 sheet. But if you use the camera to take photos meant especially for use on the internet, the size is just about right. (Note: There are CCD camera backs made to replace your 35mm camera's film back to convert it to a digital camera with very high resolution. But then we're not talking about 'inexpensive' home photography anymore)
- Battery expense. Digital cameras can be prodigious battery hogs. They include many of the features used in traditional cameras such as autofocus, automatic exposure controls, and flashes and features of camcorders such as LCD viewfinders and video outputs. They require a computer to compress the images into a manageable size in the camera's memory and get the image information to your computer. All of this usually from 4 AA batteries. They'll get warm or hot in continuous use and many cameras will not use the entire battery capacity. You could take batteries that won't run your camera and use them in radio for quite a while. If you take lots of pictures, using multiple sets of rechargables or using an external battery pack is almost a necessity.
- Low light performance suffers. There are some subjects that most digital cameras just can't handle. Unlike film photography where you can keep the shutter open and any light will continue to be registered on the film, a CCD needs a certain amount of light to function. Therefore holding the shutter open on a digital camera for hours to see star trails is not possible. When not enough light is present, instead of black, there will be considerable noise, just like a camcorder.
Each method obviously has its advantages and disadvantages. There are many ways you can rank each method
Ease of image transfer to PC
- Photo CD
- Digital Camera
- Image Scanner
- Frame Grabber
Image Quality
- Photo CD
- Image Scanner
- Digital Camera
- Frame Grabber
Extra Hardware Costs
- Photo CD
- Image Scanner *
- Frame Grabber *
- Digital Camera
* subject to caveats listed in disadvantages for each method, hardware cost is dependent upon type of device purchased and whether additional hardware to allow printer use is needed.
Speed of Image transfer (from taking picture to seeing display on PC monitor)
- Digital Camera
- Frame Grabber
- Image Scanner
- Photo CD
The next section will discuss what to do once you get the image stored in the PC.
This page last updated 01/09/01