Sony released the Hi8 format in 1989. The quality of the Hi8 format is not much different from the widely used S-VHS format of that time, but the Sony Hi8 camcorders were much more affordable than other video recording devices of that time. News stations began using the Hi8 format during this time period, and a large amount of footage from the Gulf War was recorded using Hi8 equipment.
Sony continued its innovation and was also responsible for introducing the Digital8 format in 1999, 10 years after Hi8's release. Many people embraced the new Digital8 format due to its superior quality over Hi8, along with the fact that the new Digital8 camcorders and players were also able to play the older Hi8 and 8MM tapes.
When the Hi8 format was introduced, other camcorder devices were combining the two separate chrominance and luminance signals into one wire. The Hi8 format changed this, and by using a 4-pin cable was able to keep each signal separate. This allowed the Hi8 format to altogether sidestep the process of encoding the chrominance and luminance signals, which allowed for a much better picture quality. Hi8 was still captured as analog, however, which means you will lose some quality over time when dubbing from one tape to another.
Digital8 tapes record video signals at the rate of 525 lines of horizontal resolution, while Hi8 tapes record at only 400 lines. Digital8's ability capture at a higher rate produces a higher level of color and picture quality. Unlike the older Hi8's analog format, Digital8 tapes are recorded digitally, so there is no quality or signal loss when dubbing from one tape to another.
While the differences between shooting on the Hi8 format and shooting on the Digital8 format may be less than staggering, it is a fact that the Digital8 format is far superior in quality to the Hi8 format. Digital8 is actually almost exactly identical to the miniDV format, at least from a quality and design standpoint. Hi8 is still a solid format, but because of its lower quality analog nature, Digital8 reigns supreme.