why mini dv tape format instead of a memory card?

For better video quality... for camcorders that record directly to memory card, the video is typically highly compressed. although minidv records to tape, its quality is way better than vhs or s-vhs, due to the digital signal that allows little or no quality loss. it is less compressed than memory cards, which means a better quality picture. say if a memory card held a 5 minute video, it usually would be compressed for it to fit, so lets say thats 100-200MB. on minidv, this would be around 1024MB, or 1GB. larger file size=usually better quality. basically, stay with minidv and stay away from memory cards (unless its the only option), because it will take just as much time to process each (i.e. transfer, edit, burn), and whats the point of that if youre gonna have bad quality pictures anyway? i hope this helps! Analogue video (VHS, 8mm, Hi8, etc.) is recorded at 240 lines per inch. Digital video is recorded at 500 lines per inch. Obviously digital video is much better quality, but the quality comes at a price - storage. In its native format digital video consumes about 1 Gb for every minute of video. MiniDV tape gives the most bang for the buck when it comes to storage - inexpensive, compact, reusable and most importantly fits with our "film" mindset. DVD is too unreliable for portable recording. HDD has data transfer challenges. And no one has made a memory card big enough to hold an hours worth of shooting (at todays prices that memory card would cost $4-5000!!!)

So MiniDV wins the day!