Digital Camera Interface

Once you've taken pictures and filled the memory card in your camera, you need a way to get those pictures from the card into your computer. You can either keep the card inside the camera and connect the camera to the computer, or you can take the card out and stick it in a separate memory card reader that is connected to the computer. The choice dictates how fast you can unload your pictures.

If you choose to connect your camera directly, the speed of transfer is dependent on what kind of connection your camera offers, i.e. the digital camera interface. There are currently three options.

• Universal Serial Bus (USB) 1.1 - USB was the first widespread high speed method of data transfer from cameras. It is theoretically capable of transfer speeds up to 11 megabits/second (note megabits not megabytes)

• USB 2.0 - A development of USB but much faster - up to 480 megabits/second. Looks exactly the same as USB 1.1 and plugs in to the same USB port on your computer. If the computer's port is USB 2.0 compliant, then a camera with USB 2.0 interface can transfer images at 480mbits/sec. If either the computer or the camera is not USB 2.0 compliant, then images will be transferred at 11mbits/s, i.e. USB 1.1 speed.

• IEEE 1394 (FireWire) - Though this is an older interface than USB, it's capable of high speed transfer (400 megabits/second). It was originally only used much on Apple computers. A lot of PCs now also have Firewire ports, but make sure yours does if the camera you are contemplating only has a Firewire interface (rare). This interface is more common with digital video cameras.

Each camera has an output (interface). A cable connects it to the computer.

Even though just about all cameras have at least one of the above interfaces to connect to the computer, it is usually easier to remove the memory card from the camera and insert it into a dedicated card reader. Card readers are cheap, often for $10 to $15, and many can read more than one memory card type. Another advantage is that card readers save the camera battery since the camera does not have to stay on for the transfer.

Having a separate card reader can be more convenient.

Always try to get a camera that supports USB 2.0 so you can transfer your photos quickly. But if that is not possible, don't despair because a separate card reader will make your transfers fast.

Next we look at the last main differentiating factor of consumer cameras, the shutter lag time. Hopefully, with that last tidbit of information, your digital camera decision can be a well thought-out one.