June 17, 2006

Memory Cards

Traditional photography uses film as a storage medium. When one film is used up, simply take it out and pop in a new one. The film is eventually developed and the stored images printed. Digital photography also has a form of removable storage - memory cards. The advantage of these cards over film is that they can be erased and reused. Images stored on memory cards can be transferred to a computer for further processing and permanent storage, or they can be transferred directly to a printer. Memory cards are not the only medium for image storage, but they are the most common. Other storage media include removable hard drives and optical disks.

Memory cards come in a variety of sizes, so you need to figure out how much storage space is required for your photos. This can vary according to the megapixel rating of your camera, the type of storage format, and the amount of compression used to store the images.

The most common type of compression is JPEG, but this is a 'lossy' format. This means that some of the data that makes up your image is discarded and cannot be retrieved. For most purposes this loss of data is not critical to the quality of the image and the savings in terms of storage space more than compensate for the lost data. Sometimes, however, lossy formats are not acceptable so the image has to be stored without any compression at all. This requires significantly more storage space than JPEG.

CompactFlash

CompactFlash is the most popular type of memory card for digital cameras. It is relatively inexpensive and is widely available. It is used by a number of different camera manufacturers, so if you buy a new camera, chances are it can use CompactFlash. There are two kinds of CompactFlash cards -- Type I and Type II. Some cameras can only accept one type, so it is important to know which one you need for your camera.

Secure Digital / MultiMedia Card (SD/MMC)

SD/MMC cards are the smallest type available. SD/MMC are identical except that SD cards have a write-protect switch which prevents images from being accidentally erased. They can be used in ultracompact cameras and also in personal entertainment devices like MP3 players. SD/MMC cards have less maximum storage capacity than CompactFlash cards (currently at 1 GB) but still offer enough space for most digital photography needs.

xD Picture Cards

xD Picture Cards are also very small -- less than 1 inch square. They were developed by Olympus and Fuji and are most commonly used in those brands of camera. They can be used in other types of cameras with a CompactFlash adapter.

Memory Stick

Memory Stick was developed by Sony and is used in almost all Sony digital cameras. It can also be used in other Sony devices like MP3 players and PDAs. Memory Sticks are used on very few other cameras beside Sony cameras, so switching to another brand will most likely mean being unable to use this memory.

MicroDrive

A MicroDrive is an actual hard drive housed in a CompactFlash Type II casing. Because they are mechanical drives with moving parts, they are somewhat more delicate than flash memory cards. They must be handled with care and are more prone to breakage. MicroDrives also have a slower access time than CompactFlash cards, but have the advantage of larger storage capacity at cheaper prices.

Posted by DigitalCamera at 12:18 PM | Comments (0)

June 13, 2006

Transferring Digital Images

After you have taken enough photos to fill out up your memory cards you need to transfer them to a computer or printer. There are several ways to do this.

Almost every digital camera on the market today has a USB port. This allows the camera to be connected directly to a computer for image downloads. There are two versions of USB – USB 1.1 and USB 2.0. High-end cameras are usually equipped with USB 2.0 because the transfer rate is up to 10 times faster than USB 1.1. Budget cameras usually have USB 1.1 – adequate, but other options may be more attractive.

Rather than reading the images directly from the camera, they can also be read from the memory card. Most multimedia notebook and desktop computers can read cards directly. If this is not the case you may need an external card reader.

Card readers are one of the most efficient ways to transfer images. Simply take the card out of your camera and pop it into the reader. Most card readers have a variety of ports designed for different kinds of memory cards. Card readers are almost always equipped with USB 2.0 or FireWire -- an equally fast data transfer protocol. They are quite reasonably priced.

One of the advantages of USB devices is that they can be connected to the computer while it is turned on. The computer will recognize the card reader as an external storage device and allow you to transfer data to any location on the computer's hard drive.

Other Options

For most people, storing images on a computer hard drive is the most practical solution. Computer storage allows images to be edited, sent as e-mail attachments, or posted to a web site.

However, there are other ways to download images from your camera. Cameras with a PictBridge or USB Direct Print can be connected directly to a compatible printer for direct printout. This is a very convenient way to download pictures but by doing so, you miss out on the opportunity to edit them on the computer.

Another way to transfer images is to use the camera's video output to connect it to a TV, VCR, or DVD burner. Images could be captured on videotape or burned to DVD, or simply viewed as a slideshow on a TV screen. Some cameras are equipped with an infrared remote control which allows you to flip through the pictures from your armchair.

Portable Storage

Portable storage devices are specifically designed to hold large numbers of images so that they can later be transferred to a computer. They are primarily aimed at the professional photographer who shoots several gigabytes of photographs per day. These devices are also useful when you are on vacation and taking lots of photos and don't have easy access to a computer.

These devices have an internal hard drive and are powered with rechargeable batteries. They read the camera's memory cards so that they can be erased and used again. They are often equipped with a LCD viewing screen so that images can be previewed. Images are transferred to the computer by USB 2.0 or FireWire.


Posted by DigitalCamera at 12:41 PM | Comments (0)