A friend accidentally put a fuji tape into my z1, that i usually feed sony premiums. I will run the cleaning tape afterwards of course, but i'd like to know how significant you think this lapse in regularity is?

When I first started in video I heard and read about only using one brand/type of tape in my camcorder. After doing quite a bit of research and reading many conflicting opinions I came to the conclusion that there was an incompatibility several years ago, but in the last 5+ there is no problem mixing tapes anymore.

Even after believing that there is no longer a problem with mixing tapes I have still stuck with one brand/type of tape for my 'good' camcorders just in case there was still something to the old wives tale.

The funny thing is, I have always had a cheaper camcorder to use as a capture deck. I have been through 4 of these now, and because I often capture tapes from clients, they have had every brand of tape run through them. After capturing hundreds of tapes of different brands and types, I have never had a problem with unusually dirty heads or other head clog problems with any of these 'capture' camcorders that are fed all kinds of tapes. So, in spite of what many people still teach about using one brand/type of tape, my experience is that there is no need to follow that advice any longer. I know there a some that will tell stories about how changing tapes gummed up their heads, but I have not had that experience.

I find it amazing that if there was some truth to the practice, the manufactures would be very vocal about it. I have not ever read in an instruction manual or seen any official publication from the manufacturers about the practice. If changing tapes would cause their product to malfunction I would think they would surely let you know. They don't need the frustration from users and bad reputation that failed equipment would cause if using different tapes did indeed cause their equipment to fail. To me it would be like an auto manufacture not putting a warning on diesel automobiles about putting gasoline in them.

After all this, I still use one type of tapes in my good camcorders and would run a cleaning tape through it is I changed.

Interesting. I'm sitting here staring at the client supplied Fujifilm miniDV tape that required me to run the abrasive head cleaner through my Sony PD150 (which has ONLY been fed Sony DVM60PR tapes by me) 5 TIMES immediately after it's one time only use due to badly clogged heads.

Govern yourself accordingly. I don't and WON'T mix tape stock. Your mileage may vary...