D-VHS to Hit The Market This Week

An Anonymous Coward writes: "Yahoo News is has an article stating that D-VHS is hitting the market this week. The upside: D-VHS supports full high-definition picture quality. The down side: $35 - $45 per movie (although available for less) and $2k for a player. Seems to me you'd lose a lot of that HD picture after a few viewings too. 4 studios are supporting it: 'JVC persuaded Fox, Universal, DreamWorks and Artisan to support the format after developing a new copy-protection standard it calls D-Theater to prevent unauthorized copying of the high-definition movies'."

Comments

Video Tape vs Computer Tape

[nullard]

Won't they just have a "re-tension" option on the players?

The problems are streching, physical contact, and frequency of use.

If the reader expects each bit to be X distance from the next, but the tape streches, then the read head will read some other magnetic data from the extended area. The same goes for wrinkling and bending.

Tapes are more likely to sustain this kind of wear since the process of using them involves physical contact. Take a look into an open VCR as you insert a tape. Those metal rods can damage your tape. They pull and flex the tape. The head can also damage the tape. The motors can damage the tape if they pull to hard an the tape reaches its end, resulting in a harsh jerk.

The reason that these problems are less likely to plague backup tapes is because of frequency of use:

How often do you insert each computer tape? Remember that the act of inserting the casette into a VCR causes physical contact with the actual tape.

How frequently do you use the tape at all? Don't you just write to it in most cases?
Don't you only read from it infrequently and usually only once? When you re-write the tape, it can make up for some streching (within certain limits).

More importantly, how often do you "pause" a data tape? Pausing streches tape.

How often do you run the tape at high speed while the read head is in contact with it? That is exactly what happens when you scan tapes by pushing ff or rw in play mode. That is even more damaging to the tapes than just playing them.

Sure error correcting exists, but my point is that tape is more error-prone than other forms of storage since the simple act of reading or writing the data can degrade it.