IBM Microdrive
IBM Microdrives are the size of a postage stamp and are now available with three capacities: 340 MB, 540 MB and 1 GB. While they sometimes raised problems of compatibility with earlier-generation cameras, all three of these are compatible with the Minolta, Nikon and Olympus 5-megapixel models. The characteristics of the 1 GB disk in Compact Flash format are worthy of a true hard disk. The average access time is about 15ms, with a (theoretical) transfer rate of 30 to 60 Mb/s. When connected to the Sitecom MultiReader (a card reader connected to the PC's USB port), we found a rate of 0.75 Mb/s from the PC to the disk. The other way around (disk to PC), the rate is 1.5 Mb/s.
A photo taken with a 5-megapixel camera in TIFF format ends up about 15 MB, so you can store about 70 on the 1 GB disk. In slightly compressed JPEG format, the photo is only 3.4 MB, and disk capacity increases to over 300 photos.
Image Size
| Header Cell - Column 0 | Minolta Dimage 7 | Nikon Coolpix 5000 | Olympus E-20P | Sony DSC-F707 |
|---|---|---|---|---|
| RAW 2560 x 1920 | 9700 kB | N/A | 9700 kB | N/A |
| TIFF 2560 x 1920 | 14500 kB | 13000 kB | 15600 kB | 14403 kB |
| JPEG 2560 x 1920 | 2300 kB | 1200 kB | 3700 kB | 2 MB |
| Supplied card | 16 MB CF | 32 MB CF | 16 MB SM | 64 MB MS |
| Card capacity * | 1 | 2 | 1 | 3 |
* Number of 2560 x 1920 TIFF images recordable on the cards supplied
Common Functions
By necessity, the four cameras rely on their differences in order to stand out from one another. We'll investigate these differences later. In the meantime, let's look at the many points they have in common.
