Let's do a test! After all we're all tech geeks one way or another,
can you think of a better way to spend a saturday afternoon,
Round up a few cameras and a few tapes and publish the results.
They've done it with microphones, why not tapes.
If you're a professional shooter I can understand why you wouldn't
want to put your gear at risk. But a few board sponsors wouldn't hurt?
Food for thought...

I went from using Maxell to Panasonic in the VX2000 I used to own.

I had a whole lot of problems with needing to clean the heads a lot more often to drop-outs. I also had good results.

Now, were the problems caused by mixing the brands as I could have assumed, a few bad tapes or compatibility problems?

Well, one tape got stuck in the camera and would not come out. It would not eject. I had to very carefully pry it out and not damage the camera doing it. Hint, bad tape problem and not mix.

If a problem(s) just happen to start right after one changes brands, then one might consider the tape mix warnings that people talk about to have merit. Wether they do or not.

So they then say 'yes, it is so'. Well maybe it is and maybe it isn't.

Now that many including myself have gone tapeless the whole point is moot and I am no longer concerned with tape problems.

My overall time of getting my video work done has significantly improved since I went tapeless.

Perfect? Trouble free? One can only wish, however tapeless is so much better than using tape.

Some time very soon, all will be saying things like, remember when we used to talk about tape problems and the possible myths associated with them?

The price of cameras could be reduced if the tape mechanisms were no longer included. A hint to the camera manufacturers.

There is an end to that "The Long Black Line" and the end is clearly in sight.

Danny Fye
www.dannyfye.com

Is this possible:

The recording heads and mechanisms on a camcorder are more sensitive than on a player?

Example: The pd170 vs the dsr20.

I share a dsr20 with my boss and we use a great variety of tapes with no problems.

Just curious.

just my 2 cents
 

This has been explained a little bit more scientifically in a lot of previous posts, tho kind of veiled as it lies in common sense :). There are 2 main lubricants used on tape media (from old reel tapes to the new HD dv), one is the more common "wet" lubricant , a liquid which is coated across the element. The other is a "dry" lubricant, a graphite type material. Both do a great job, except when mixed. Mix water and dirt and you get mud :/.
While it is easy to mix brands and not have any problems, if you start mixing wet and dry lubricants, heads can get real dirty, real fast.

Well, we mix wet and dry on his dsr 20 and he does not care.

We have no problems.

He laughs at me because I won't mix tapes on my pd170.

My question is still there: Does mixing tapes negatively affect camcorders more than decks?

Well, I don't know jack about this, because I have used exactly one brand and model of tape in my XL1, Panasonic, and it is very easy to reorder. Why in the world would I try to paddle upstream when I have a brand and item number that will get me more of the same ol' reliable tape? Hundreds of them in my case.

I think it's mainly about reducing or minimizing variables in production. Heaven knows I always seem to forget one-little-thing on every shoot, but at least I'm consistent!

Okay, let's be scientific. If it were true that components in the two lubricants react chemically to form a troublesome third compound (already dubious), it would require mixing of the two at some time and place, and time for the reaction. There is great variability in reaction times for various chemicals, and it is not chemically agressive substances that are chosen as lubricants so it would likely have to be a slow reaction. To my way of thinking, a few micrograms of one lubricant left on a camcorder head by one type will be flushed and brushed off in miliseconds by the lubricant and tape motion of the next type.

The main source of goo that can actually stick to heads is degraded binder from the tape. itself. Here's what I consider a scientific article on tape failure: http://www.clir.org/pubs/reports/pub54/2what_wrong.html

From what I've heard, if you mix the different lubricants often enough that no one type has enough time to build up on the tape head, you are at much less risk of problems that if you use one type for a long time and then switch to another type.

As for me, I don't know if the advice to use one type of lubricant is actually based on true problems caused by mixing the two types, but I figure it is worth playing it safe, and so stick to one brand of tape. Why ask for trouble? I've got enough of it already. ;-)

As stated previously, it's about reducing variables. At the very least if you did have to get your heads repaired/professionally cleaned and the tech asks you "did you switch tapes", you honestly say "no, never I used <brand> tape always". And thus eliminates one possible cause for your issues.

Here are my anecdotes for posterity:

This weekend I used an SVA (School of Visual Arts) PD-150 on a shoot. Out of respect for SVA's equipment bought Sony Excellence tapes. Got the camera, Panny MQ stuck in there. Ran a cleaning tape in there before starting. Over 2.5 tapes in DVCAM mode, the camera barked "Cleaning Tape" 13 times. Hours on the heads were about 80. Could have been some other issue, could have been the tape switching, we won't ever know will we. I did look like a wanker always asking to stop to clean.

Couple weeks ago, I shot a corporate video with a VX2000 owned by the corporation. I've worked with them for years. They order Sony Premiums in bulk and that's all they run. The maintenance on the cams is nonexistant - no cleaning tapes, ever. Not one "Cleaning Tape" message across 4 tapes.

I borrow a friend's DVX100 to shoot stuff on occasion. I asked her any particular brand of tape? Nope. Care for the cam? She lost the lens cap because she threw it at her boyfriend's window to signal him. Out of respect I use Panny MQs but I know all sorts of tapes have been in there. No problems despite the mixing.

My point, based on my experience I don't know if mixing is an issue. But as Chris said before, it's about liability. I shoot narrative stuff mainly (so you can always get another take) but if I shot events and owned my equipment I sure as hell would stick to one brand just to be safe. Last thing I want is a bride and groom suing me because I missed a shot and their videographer friend saw me switching tape brands. I'd rather get sued for incompetence than for something as trivial as tapes.

Hi Chien, and welcome aboard.

On one hand, I'm a little annoyed with you for dredging up this tired old thread, but on the other hand I agree with your points completely. Thanks for your input!

As I've said before, the official position of DV Info Net recommending against switching tape brands is primarily to protect myself legally. I don't want someone thinking they can hold me responsible for a messed-up shoot because I said it was okay to change tape brands. It's simply safer from a legal standpoint to continue to recommend against switching tape brands, unless somebody can conclusively prove why I shouldn't. It doesn't matter to me if some folks think the "scientific burden of proof" is upon me to prove there's a problem. I'm not concerned with that at all.

What I am concerned with, is that there is substantial anecdotal evidence right here on this forum that it is a problem, and somebody's attorney might get the bright idea to say, "well, you should have warned against that, or at the very least, not condone that practice" of switching tape brands. So here it is. The flip side is that nobody is going to come after me with a lawsuit for recommending *against* tape brand switching. Even in the following situation quoted below:

No chance of liability over that, no question about it. I'm not responsible for your poor planning which resulted in you not having enough blank tape stock of the same brand for your vital shoot. In other words, if you come up short of your preferred brand of tapes, that's a result of your own poor planning and is entirely your own fault, not mine.

It's not about "scientific evidence" at all, although I would welcome a bonafide scientific study. Frankly I don't have the ways and means, nor the desire to undertake one myself, but I would be very interested if somebody else did. The real issue here is liability -- and for that primary reason over everything else, this site officially recommends against the practice of switching tape brands, unless somebody can give me a compelling reason *not* to. Hope this helps,

Hello Chris,

Sorry this topic annoys you, but I don't see why it should. It's perfectly reasonable to discuss, isn't it? Shouldn't unresolved issues that remain of interest to people always be open for conversation? I'd sure hate to always have to worry about posting something interesting on a forum, like Chien did, for fear it might annoy the moderator -- even if you meant that partly in fun.

Anyway, as long as you repeated your liability theory...

1. Obviously you cannot control who sues you for what. Anybody can sue you for anything. The question is whether they can get anywhere with it (as you illustrate in your above post).

2. As I explained previously, you are in no way liable if you honestly state the facts: that on the one hand there is a good deal of anecdotal reporting of tape switching apparently causing damage, and there is a clear working theory for how this may happen, but on the other hand that other anecdotes report no problems, and the working theory is disputed by some -- and therefore, until you learn of a proper scientific study, you cannot form any rational conclusion or offer an official position. You can explicitly state that you are in no way liable for anybody's decisions, and that you may not have the best or latest information, and advise people to do their own research and make their own decisions. If anyone wants to know your personal opinion for the hell of it, they can ask you.

Simple as that. Clear, honest, and legally safe.

If you really want, you can advise people that if the arguments against tape switching which they read on this forum are sufficient for them, and if they see no significant downside to sticking with one tape brand to the exclusion of trying others, then they should probably stick with one brand to feel safe. You can even warn them that clients could potentially attempt to sue videographers whose cameras malfunction after having switching tapes (as Chien points out), but that you have no idea if they'd have a legal leg to stand on and that's a question for attorneys, not you.

I appreciate your situation and concern, but it seems misplaced: the argument for taking an official position for legal purposes does not seem to make legal sense. Again, I say this with tremendous respect and solely with your best interests and those of your board's participants at heart.

For those who make the "what's the harm?" argument (in regard to offering an official position), that's utterly irrelevant, especially in light of the fact that there is no actual benefit. (There may or may not be any harm in people carrying rabbits' feet with them at all times while shooting video, but if there's not, that's still no justification for telling people they should.) Nevertheless, for those who haven't really thought about it or remain curious, various aspects of the potential "harm" have already been discussed above (not limited to the part of a single example quoted in the prior post).

Best,
Glenn

What about switching the rabbit's foot from the left pocket to the right pocket during a shoot? Will it cause bad luck?

The official DV Info Net position is to keep the rabbit's foot in your left pocket.

An easy way to remember this is, "right is wrong, left is right."

I will not be held liable for problems incurred via either pocket, however,

Well firstly as the issue has always been referred to as a problem induced by mixing wet and dry lubricants the the simple act of switching brands is irrelevant unless you do have a problem.
For example switching from Panasonic to Sony stock has no correlation to the issue if they both use dry lubricants. However switching between two Panasonic tape formulations used to cause this precise problem as one used dry and the other wet lubricants and I seem to recall Panasonic advising that you stick to the one formulation.
The issue is further clouded as manufacturers seem not to say what type of lubricant they use and furthermore the theory is that you have to use one type of lubricant for an extended period and then switch to induce the problem.

We hire DV equipment and sell DV stock. We used to sell Panasonic stock and then switched to Sony. That's a lot of head hours of one brand followed by a different brand. No increase in error rates seemed to occur however we did check that both tape formulations used dry lubricants.

None of this can easily be determine scientifically, the key piece of data cannot be determined easily, namely does a tape use dry or wet lubricant. One could build a matrix of data and try to deduce something from that, you'd also need to filter out a lot of noise from random events, and need a very large dataset to get good confidence.

Looking at the advice being offered I see it as:

Try to stick to the one type of tape. Do this by keeping enough stock on hand. Good advice anyway, who wants to run out of tape. At the least it's an inconvenience, at worst you could blow a shoot.

If you must change tape type and you've been using the same one for an extended period clean the heads first. What does this require you to do, have a cleaning tape on hand. You're nuts if you don't anyway so there's no down side to this advice either.

Wrong advice is only bad advice if it has a negative impact. If anyone can see a negative impact from following this unproven bit of advice then and only then need it be called into question. So far at worst it's unproven advice, not bad advice.

If the advice is to only use stock xyz and it's 10 times the price of every other stock, that's advice that deserves serious scrutiny.

I'd add my own unscientific bit of advice. Use Sony stock in Sony gear and Panasonic stock in Panasonic gear. Only because if you have a problem with the gear they can't weazel out of it with some spurious remark about the type of tape you use.

Most excellent, Bob, many thanks for your input -- much appreciated!

Bob/Chris: Yeah, the wet/dry theory has been discussed earlier on this thread and elsewhere. That was the "working theory" I referred to. Many experts say the wet/dry theory makes no sense, that wet residue evaporates quickly and nothing else causes a problem. In other words, the working theory is bogus, according to some. The latest report saying as much aired on NPR a few months ago, but I don't recall who the expert was so I realize that's of little value.

People keep bringing up the "what's the negative impact" question without noticing that has already been discussed, but it's understantable, 'tis a long thread. Not worth repeating. Clearly various points that have been brought up will be left unaddressed, but it's not important. It was just an interesting question Fred originally raised, to analyze and understand, and hear different people's takes on.

Chris: thank you for the rabbit's foot advice. I made the switch and that very day sold a project! (Thanks also for the big laugh!)

G

Glenn, thank you for this and your informative and balanced contributions on this subject. I hope that the quoted expert contradiction of the popular underlying cause-effect theory is given due consideration by the people who have been following this thread.

I have no doubt at all that I'd prevail in such a situation, but I don't want to even bother finding out. That's why I'm sticking with the "no switch" advice. For the last time, as far as I'm concerned it is a liability issue and nothing else. If that bugs somebody to the point where they can't handle how unscientific that position is, then my firm advice is to excersize your freedom of speech and go start your own web site / blog / whatever and preach it from your own platform... because this one is spoken for already.

It doesn't bug me. Your position justifiably transcends the question of whether the "use one brand" advice is scientific or not. Meanwhile, the question itself is quite well settled in this thread. For whatever portion of the three thousand or so readers to date make their decisions on a scientific basis, I think that's a service. For the unscientific types, no harm no foul--they'll just believe and do what they wish.

Wouldn't it be great if we had a list of all the tapes that includes all the different models each brand sells with information on who actually manufacturers the tape, who makes the housings, and what type of lubricate is used, etc. (I -SUSPECT- that a lot of the tape and/or housings is really manufactured by a very small number of companies then sold by different brands.) If you read the packaging on most tapes, they make up technology names for their special features or else they write something like "special coating to protect recording layer" - what the heck is that really?

Real information on tape formulation would be the first step in getting to the truth of this matter. But we all know this will never happen, it's all a big secret.

So I stick with one brand because I have no real information I can rely on...

I buy my tapes in bulk, so I only use one brand :P

I've used the Sony premium tapes in my XL1 and XL2 for years. Never tried another brand. I buy them because after thousands of tapes they've never failed me, and that's enough for me to be loyal. Plus, they are cheap in large quantities (by the hundreds), and that's always important.

Just find a tape you like and stick with it. I don't see the big deal?

My experience with mixing tapes landed me in serious hot waters, I have compleatly lost one serious shoot that I never could repeat. Now I am horrified of brand switching. This happened even when I cleaned the head before.

Yep, exactly, I found a tape I like, and I have used one flavor of tape in my XL1 for years. And as you pointed out, when you buy enough pieces of one thing, the price goes down. Get a hundred at a time, and you get the right price, plus you never run out and get stuck using something you are not sure about.

Wow I've never actually read through this thread before. I'm honestly kind of suprised.

I particularly enjoyued the argument derived from descartes (I think) that if it's true you've got everything to gain and if it's not true then you've got nothing to lose, now he was originally arguing for the existence of god, but I'm sure were he around today it would be over tape stock switching.

The issue I have with keeping with one tap style is this, say for example you happened to receive a couple of cases of tape stock for your brand new (insert camera here) this is the super duper high grade stuff something like oh I don't know the sony digital master HDV stock. Now suppose that you've used it and everythings been great BUT the f-ing tapes are getting expensive, you see those sweet looking panasonic master quality tapes hanging out at 5 for the price of one of your sony's and hits you that if you shoot a modest 200 tapes a year you're spending around 3k on siny digital masters where as you'd only be spending around 600 bucks for the panasonic tapes. 2400 is a lot of dough, and to be honest at that level it may be worth it just to bite the bullet switch see if there is in fact an issue and if there is send the camera off to be cleaned (probably less then 1k for the pricess) and start over with the panasonic but that's defeats the point of the post.

So seriouslyhas anyone done this test? surely someplace like dv.com or consumer reports or someone has done some sort of comarison? I really don't think fred was intentionally attacking anyone I think perhaps he was just curious as to if the tale of caution can actually be founded on scientific data and perhaps was jsut appealing to us as community to find out if there was any sort of cold hard sort of data like

panasonic uses x chromosomes
sony uses y
if you mix them they give birth to gunk in your camera.

did I miss the sport where someone actually referenced any other site or source?

You're referring to Pascal's Wager. I'm proud to say that I end up on the same side of the argument whether we're talking about the existence of God or tape-mixing issues. :)

To my knowledge, nobody has ever published any such test results; I'd gladly link to them if they did in fact exist; no I'm not about to commit any of my resources to such a test because I've got a mountain of more important things to do; if somebody out there wants to go to the time and expense of mounting a valid, objective scientific experiment, then I say go for it and more power to you. And please let us know the results.

I own a Sony VX-1000. I have operated that camera since new with only Panasonic tapes. Never a problem.

However, in 2004, I decided to switch brands to Sony tapes. After only shooting a few tapes, things started getting really weird. I'd see green bars when I played the tapes back.

I cleaned the heads with a tape cleaner, and it worked ok for a while, but the green bars would come back, and I'd be dropping timecode left and right. It would 'reset' each time I stopped recording.

Eventually, I sent the camera to Sony for a lens replacement. There were large dust spots on it, and I also had them check into that problem.

The camera came back, and worked fine for a while, but with Sony tapes, it starts getting the green bars back.

I now own a Z1U and ONLY run Sony tapes in it, period.

That's my first-hand experience.

Jim

Great article - refers to some old technology. Who's willing to ruin their oven by baking a DV tape for 3 days? Okay, cheap shot - it's a great article, reminds me of lectures (OMG) 20 years ago. And the pain of being strung out on caffeine trying to explain the impact of Hysteresis in 2000 words.

Maybe tape brands are like food.

If you mainly eat fish curry with rice, pretty much every day, with leftovers for breakfast, and suddenly you have to eat a Pizza Hut Stuffed Crust, your digestive system says no. Swap the circumstances - pizza is the only food group, then one day someone gives you 'American Hot Sardines' with rice on the side. Your imagination can fill the blanks.

If you're a globe-trotting international restaurant critic, this is not going to be a problem. For the rest of us, well...

Your desire for empirical scientific analysis is laudible, but please remember that the 'request' is for proof that very few potential sponsors want to hear. No tape manufacturer will fund this research. No camcorder manufacturer will fund this research either, as they happen to own a tape manufacturer. Here in the community, we can't demand that our colleagues pistol-whip their kit to prove something that they already know by gut feeling.

What you're demanding is expensive. Come to the DVinfo picnic, demand Foie Gras, demand certification that all products are organic. Wholesome. Accountable. That's good. And how would Sir like to pay?

PS: Virtual beer to all those who are participating! :)

Nice post otherwise, but I take serious exception to this statement. First of all the are very few sponsors here to begin with... just compare this site to a number of others which are literally saturated with advertising. And while a handful of sponsors make this site possible, they have little to no impact on what I choose as its focus. As I said before, there are two very plain reasons why I won't pursue any such testing here: I have neither the *time* nor the *money.* I simply can't afford to do it, because of limitations on the clock and in my wallet.

Now -- also as I've said before -- if somebody, anybody out there wants to torture their own gear and conduct their own objective, scientific testing and show some conclusive results -- then I'd be more than happy to host it or link to it (because on this site I'm the one setting the table, not my sponsors).

Also, I've changed the title of this thread (finally) because the former moniker of "Mass Hysteria" was itself more of an emotional appeal than a scientific finding.

Apologies, Chris - I wasn't inferring connection with DVinfo sponsors. My intention was to point out that shareholders in a DV tape manufacturing company would be uneasy about their company funding research that would undermine their market share.

Here in the UK we have very expensive petrol. What does the market do? Do they purchase the cheapest fuel and fast-track their engine to failure? Do they purchase premium brands that promise efficient performance over cheaper brands? Do they put additives in their tank to lower the effects of cheap fuel?

OTOH - and I throw this analogy in for free - I've sacked garages for trying to save me money by fitting cheap brake pads to my cars. They all stop efficiently, they all last a long time, but the non-brand cheapies all squeal like a wire brush down a blackboard. I'd rather pay the extra than have the embarassment of all those horrified faces outside a client's premesis. And if I ever got a drop-out on a vital take, I'd rather state that I'd used the best tape available at 4 times the cost of consumer brands as it was less than 1% of the total budget, rather than suggest a re-shoot.

More on media than you may care to know...
 

Here's what perspective I can provide, having worked and involved with both hardware and media for two companies:

- There are manufacturers that produce both their respective media and hardware. With regards to HDV and DV, Sony and JVC design and build both. I have been informed Panasonic does, too.

- Specifications on tape formulation and tape path tension vary. Sony specifications call for a tape path that is more rigid/tense than JVC, and is considered unique to their equipment. JVC tape path tension is considered more mainstream in comparison.

- Tape formulation is designed to provide the best performance for the equipment they are specified to work with. A large number of physical characteristics are in play, from the amount and strength (physical and electronic) of magnetic particles/evaporated ingots being used, the resulting level of friction resulting from the coating process, to the rigidity of the resulting formulation. Back and top coating technology also play a vital role in the performance of the media. All of the formulations are quite involved and incur many years of R&D and fiscal investment. Imagine the amount of study that goes into just determining the best method of combating friction between the spinning recording drum head surface versus the magnetic tape layer.

- Optimization occurs when a single media formulation is used over time. This would explain how a camcorder/VTR that uses a single brand has little or no issues in operation. This would also be an explaination why a camcorder/VTR that constantly has multiple types of media being used doesn't fully become "engrained" and may not have any issues.

The negative results from using an alternate media brand after the camcorder/VTR has been optimized with a single brand can also be explained by this. I've experienced the latter many times over investigating defective media from broadcast customers when Betacam tapes were being returned for edge damage because the photog had to use a different brand on a shoot. The edge damage occured because the tape path width on the drumhead was optomized for Brand A, and Brand B's media was wider, causing the edge damage to occur. And, yes, even media slitting technology and specifications differ from manufacturer to manufacturer.

So, is there merit to the comment of using a single brand for the best results? I found this to be true. Is there such thing as an ideal match between media and hardware? That's what the manufaturers struggle to provide especially at the professional level because that's what shows the product, hardware and media, in the best light (i.e. to specifications).

Each person has their own reason and choice on what media to use. Hopefully the information above helps clarify some thoughts. One thing to remember, though, is that the content you shoot ultimately ends up on the media.

Good luck, everyone, and happy Thanksgiving.

PS: I've learned that JVC manufactures calibration media for DV and HDV hardware, and is the manufacturer of HD-D5 media. Prior to joining JVC, I didn't know they manufactured media, so I was quite impressed by this fact.

*This posting is dedicated to all my friends in Dothan, Laredo, Sendai and Mito. Many thanks for all the education and support you've kindly provided through the years.

Craig,

Thanks for your inside input.

Correct me if I'm wrong, but you seem to be saying not only use the same brand all the time, but find out which brand specifically matches your cam and use that brand all the time. Yes?

Hey Craig, thanks a TON for your input on this topic -- it's much appreciated!

Yes, Barry, that would be ideal. But as I have mentioned, each individual has their preferences and circumstances. The level of media technology has advanced greatly along with the hardware, and there are a number of quality and stable products on the market. If you can't afford the optimal media, then I would suggest at least choosing a professional application product, simply because they are designed for such use.

I don't have the brain power to read this entire thread but my take is the same as the man before me, get what works for you. I spent alot of dough on my XL2 and using anything but the best of the best in tapes seems dumb to me. Do you really trust that special shoot of yours on a cheapo DV tape? I don't, so buying the best tapes I can to protect my investment causes me naturally to buy the same brand of tape. Its just fate I guess, lol.

-Kyle

Craig (see posts above) is an articulate and appealing gentleman, as one who has risen to National Marketing Manager would have to be. I, too, appreciate his contribution to the discussion. Compared to him I'm sure I sound like an argumentative crank. I somewhat regret the abrasive tone of my original post, which was meant to evoke thoughtful opinion and any real sources out there, but went a bit over the top. I welcome the change Chris made in its title. However, I stand by its content. I'm an engineer, not a marketeer.

So to me, "use one brand" is still a superstition, and all of the dissenting posts in this thread fall into the categories I predicted. I could elaborate point by point, but I know I'm already stretching Chris's patience on this subject. I respect Chris and I love this forum. Incidentally, I never suggested that it was Chris's or DVINFO's responsibility to perform a study.

Good grief. Kind of amazing to me that a topic like this can be so touchy, but here we are almost 80 posts later! In that light, it is with some trepidation that I finally elect to comment.

With those inconsistent statements, the thread-starter acknowledged that he does not know if there is truth to the concern, yet in the next paragraph asserts that it is urban legend or folk wisdom, and further feels compelled to intervene by starting this thread because unnamed persons have proclaimed it as "real information." Well, it IS real information in the sense that many people anecdotally report problems; but presumably his meaning was "established fact" which is correct -- it isn't.

However it is a fact that the probability of having tape incompatibility issues is zero when you only use one tape formulation. Since nobody, including Mr. "Retread" himself, has taken up his call to do what would be a very large and expensive undertaking to conduct a statistically valid scientific study of the subject, we can only say that the probability of tape incompatibility problems due to switching brands cannot be lower than sticking to the same brand, and may well be higher, since there are numerous anecdotal experiences. (Scientifically speaking, anecdotal reports usually do not in and of themselves prove a point -- although they can in the case of refuting a null hypothesis -- but OFTEN are the first indication of a real problem. The medical literature, for example, is replete with instances of anecdotal case reports that led to tremendously important changes to medical practice. Thalidomide and birth defects, the discovery of AIDS, Vioxx and heart disease, tainted spinach...and on and on got their beginnings in anecdotal reports.)

When the question gets asked, some people who have had problems in temporal association with changing tape brands will generally chime in with their anecdotal experiences. Nobody states there is scientific proof available. In the absence of manufacturer statements and/or controlled studies, most of us simply choose to take the zero risk approach. Mr. "Retread" has used different brands of tapes, not experienced problems, and has chosen to discount anecdotal reports while continuing to mix tape brands. Cool. But that does not DISprove that there may be a significant risk. Every day, lots of people run a red light and DON'T get T-boned.

And any of us may make that choice in tape usage, too, if we want. Nobody says otherwise. But most of us don't, because we intuitively realize that we are comparing zero risk to unknown risk to our expensive cameras. Unless you happen to have planned poorly so that you've run out of tape at a critical time AND can't get your usual stock, there is just no down side to sticking with the same tapes that have always worked well for you. So I choose not to tempt fate and do use the same tapes. Y'all do what you want.

Pete makes a few good points in spite of his demeanor. "established fact" would have been a better choice of words than "real information" in the initial post. And anecdotal information is not only sometimes the first indicator of a real problem, but is the normal indicator of a problem. The trouble is that anecdotal data also often results in informal hypotheses about the problem and then is taken as proof of such hypotheses. That's the formula for widely disseminated misinformation.

Yes, it would be logical that sticking to one tape formulation would carry a zero probabiliy of tape compatability issues. But I wouldn't infer that I will achieve the one formulation ideal by sticking to one brand. Far from it. There are quality variatons in raw materials, manufacturing process control problems, substitutions and formulation changes without notice, and plain screw-ups. Add in the tremendous variation in tape cassette mechanism drag, and it's a crapshoot whenever you grab a tape, be it from the same brand as before or not. Personally, I don't believe that brand is the biggest factor in tape variability. Fortunately, the bottom line is that the odds of a good tape are highly in my favor whatever I choose.

Finally, yeah, there's no downside to sticking with a brand that has worked for you. Oops--that is, unless you're missing out on a better brand you been afraid to try because of the warnings.