15. File Storage

Canon and Nikon have both remained faithful to the Compact Flash format for storing image files. Both can use Type I and Type II cards (including Microdrives). CF remains the professional standard, and is also the least expensive. It also offers the widest choice of capacities (up to 8 GB) with transfer rates that can be very high: 133X, or 20 MB/s, has been announced for the SanDisk Extreme III.

With the 350D, you have a choice of three image sizes and two JPEG quality levels. Added to that is RAW format, either alone or with a maximum-quality JPEG image. For the D70s there are also three image sizes, but with three JPEG quality levels. RAW is recorded alone or with a JPEG image in minimum (basic) quality. Nikon's choice of RAW+JPEG seems to make more sense to us than Canon's; if you take shots in RAW it's to get maximum quality, and the JPEG file is only there to provide a readily-available reference image. "Basic" quality is sufficient for that purpose, and even for other purposes, and it significantly increases the number of shots that can be stored on a memory card.

Needless to say, RAW mode - recording of the raw data from the sensor with 12-bit quantification - is the preferred choice of demanding users. To be used as photos, RAW files require specific processing with appropriate software, which we'll mention later in the software chapter.

Approximate file size (full size)

The size of the files is subject to significant variations, especially with the Canon. It depends on the detail level of the subject being photographed, and the ISO setting used - to the camera, noise is considered data so it increases the size of the file. This means it's hard to predict exactly the number of shots you can put on a given memory card, unless you're dealing with many similar images.