What's the current thinking on how long the signal should last on miniDV tapes if properly preserved?

Also, I wouldn't reuse the tapes. I found out the hard way that this dirties up your heads and makes for uncertain recording as you are more inclined to get blocks in your picture, sound issues, etc. Use them once and then use another.

As for storage- there are some master level tapes that are supposed to be made for storage purposes. They cost around 10 bucks a pop for the 83 minute tapes. I use the pro 83 minute tapes which are about 7 bucks a pop and just leave the footage on there. I know that some on this forum say not to use the 83 minute tapes b/c they are thin and more prone to breaking. I personally have never had that problem and I have used hundreds of them. I use the panasonic professional 83 minute tapes which can be bought at b&h for cheaper than I have found elsewhere. Make sure that whatever tape you use, stick with it as different tapes use different lubes and it could dirty up your heads.

j razz

DVD longetivity is sketchy... the cheaper brands can degrade in 1-2 years (!).

Maybe in 10 years, backup all your miniDV tapes to hard drive or blueRay or HD DVD. Prices will have dropped a lot by then. And by having 2 copies, you will be golden. The miniDV tapes should last until then.

Tape lasts a LONG time. So, likely, will good quality DVD. However, if you want something to archive, just keep your DV tapes. They'll very likely play just fine in 10, 20 or even 30 years. I regularly play video tape that is 25 years old, and audio tape that is close to 50 years old. Analog may degrade a little more gracefully than digital, but I think the DV tapes will be just fine.

However, you DO need to pay careful attention as to how you store these tapes. Keep them cool, in a place where temperature and humidity do not vary much. Pay attention to stray magnetic fields, like magnetic latches on cabinets, etc. It is surprising how difficult it is to find a room that doesn't have a permanent magnet tucked away somewhere. Every few years, you should fast forward or rewind them, to avoid "print through" although I'm not sure whether this is a huge deal or not.