Mixing different brands of tape:
In DV's early days, Sony and Panasonic tapes used different lubricants, and if you used one brand a lot and then switched to the other, incompatibilities between the lubricants (which get deposited on heads and tape guides) could cause VTRs to jam up or the heads to clog, sometimes permanently. Supposedly the lubricants were made compatible starting in 1997, but I'm still hearing horror stories about these problems in the summer of 2002.
This is not a DV/DVCAM vs. DVCPRO problem; while many of the people reporting the jams are inserting the occasional DV tape into a DVCPRO transport, many others are seeing the problem in DV and DVCAM equipment, which (high-end DVCAM gear aside) can't play back DVCPRO to begin with. It also happens when other brands of tape are intermingled, not just Sony and Panasonic.
Anecdotal evidence would seem to indicate that the biggest problems occur when one brand of tape is used exclusively for a long time, and then the other brand's tape is used: instant mess! If one switches back and forth between the different tape brands frequently, say, switching between Sony and Panasonic every three or four tapes, the problems don't seem to appear.
Frequent switching apparently prevents a critical mass of one lubricant building up in the transport; switching tapes may clean off accumulations of gunk before they get heavy enough to cause problems. Whether this is really a solution, or if frequent switching only leads to a longer-term buildup of cross-contamination pollution on the tapes themselves, is unknown.
I run about 50% Panasonic DV tapes in my gear, with the remainder being a mix of Sony DV or DVCAM, JVC, and the occasional Fuji. I've never had a problem. It's rare that I run more than four hours on one brand before using the other brand of tape, so that may be a good starting place as to what a safe interchange frequency may be.
Thus there appear to be two general approaches to this problem:
- Pick one brand of tape, and ?stick? with it (sorry about the pun!). You simply won't see the problem. If any foreign brand of tape comes into your facility, do not put it into your VTR; make a FireWire dub of it onto your chosen tape brand on your machine, using the client's camcorder or VTR as the source deck.
- Interchange tape brands frequently, so the gunk from one never builds up a critical mass inside the transport to jam up the other tape when it's inserted. Always clean the heads when changing brands, too.
Problems with tape interchange of this sort seem to be reduced by using a tape cleaner in between the different tapes. Especially in this instance, do not rewind and reuse the cleaning tapes; you'll just be mixing old gunk with new if you do so. Also, do not wait until you've run one pass on the new brand tape and seen blockies or dropouts: using the cleaning tape at this point may only polish the gunks firmly into the heads. Clean the heads before inserting the new tape.
Your results may vary: and if you've had any positive or negative experiences of this sort, I'd like to hear your story...
Last update: 08:15 PM Saturday, January 28, 2006