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Wet and Dry tapes?


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#1 Karel Bata

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Posted 16 May 2009 - 08:22 AM

There is much internet debate concerning whether Sony videotape uses a 'wet' or a 'dry' lubricant.

This is an issue because the two tape types should not be mixed, and the advice often given is to avoid Sony altogether because they are 'wet'. Google wet +dry +tape and you'll see what I mean.

This issue was addressed in a DVi thread here http://www.dvinfo.ne...hp/t-97204.html
"Wet and dry was an issue years ago in the early days of MiniDV, and at that time all tape was Panasonic or Sony. After the initial problems, they got together and resolved the lubricant compatibility issues in the 1990s." and Canon are quoted as saying "We do recommend a dry type luberciant which appear to be the only type on the market for miniDV." But still the myth persists...

Or is it a myth? Can anyone verify this one way or the other? :(
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#2 John Brawley

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Posted 16 May 2009 - 08:53 AM

Or is it a myth? Can anyone verify this one way or the other? :(



I don't think it's a lubricant issue. After all the tape doesn't actually contact the heads.

When Mini DV was first released in the 90's, I did see 1st hand several instances of DVCPRO decks having unusually high head wear leading to the heads needing to be replaced inside of 500 hours when their regular life was meant to be 2000 hours. It was put down more to the fact that ME and MP tapes were being mixed together in the one machine. DVCPRO tape is Metal Particle and Mini DV is Metal Evaporated.

This was only ever seen on decks, and specifically Panasonic decks where both formulations would be played. I think it transmuted into a "Sony tapes are a problem in Panasonic decks" myth because a lot of people were using DVCPRO decks to replay DVCAM tapes which are ALSO ME tapes. Lots of people bought the DVCPRO decks, the thinking being that they could replay all formats. Why buy a DVCAM ONLY deck for the same price when you could get one that ALSO did DVCPRO...?

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#3 Karel Bata

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Posted 16 May 2009 - 09:05 AM

"the tape doesn't actually contact the heads"

How does it avoid that? Looking inside the HV-20 I just bought cheap on e-Bay (I'm in a PAL country, so it comes with 25p - the HV-30 here is irrelevant) I don't see how the tape wouldn't make contact. What am I missing?
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#4 John Brawley

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Posted 16 May 2009 - 05:51 PM

"the tape doesn't actually contact the heads"

How does it avoid that? Looking inside the HV-20 I just bought cheap on e-Bay (I'm in a PAL country, so it comes with 25p - the HV-30 here is irrelevant) I don't see how the tape wouldn't make contact. What am I missing?



Do a search on "head gap".... You'll find it's in the microns, *but* that is still a gap....

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#5 Karel Bata

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Posted 16 May 2009 - 06:17 PM

I think we're talking at cross purposes. My understanding of a head gap is this:

Posted Image

A CD or DVD head will float on a miniscule cushion of air - hence they never wear out. But magnetic tapes heads do (I believe) make physical contact with the tape. Otherwise you wouldn't get tape head wear. Nor clogging.


Anyone able to shed light on this wet and dry thingamy..? The net is full of discussion on this, but I can't find one piece of solid verification.
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#6 John Brawley

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Posted 16 May 2009 - 06:22 PM

A CD or DVD head will float on a miniscule cushion of air - hence they never wear out. But magnetic tapes heads do (I believe) make physical contact with the tape. Otherwise you wouldn't get tape head wear. Nor clogging.


Anyone able to shed light on this wet and dry thingamy..? The net is full of discussion on this, but I can't find one piece of solid verification.
[/quote]


If you look at a head DRUM that contains THE HEADS, you'll find that the HEADS are RECESSED within that drum. It is the drum that is contacting with the tape. Clogs happen when the tape sheds particles that fall into the recessed area (or any other foreign matter really).

You seem to have searched pretty comprehensively. Don't you think if it was more than a myth then there would be more informed info out there ?

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#7 Karel Bata

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Posted 16 May 2009 - 08:13 PM

If you look at a head DRUM that contains THE HEADS, you'll find that the HEADS are RECESSED within that drum. It is the drum that is contacting with the tape. Clogs happen when the tape sheds particles that fall into the recessed area (or any other foreign matter really).

Ah. That's an air bearing (I think). You said head gap. Of course - it's recessed. That's how it works. I knew that once. :lol:

You seem to have searched pretty comprehensively. Don't you think if it was more than a myth then there would be more informed info out there ?

Agreed. The fact that a lot of people believe something on the basis that someone else told them it was true doesn't make it so. And the fact that some folk say it used to be true but isn't any more suggests how the belief may have got widespread in the first place. It's a sticky memetic virus. But it might still be true. Intriguing this. Strange that the tape manufacturers are so silent on the matter. So will anyone here step forward and say they actually know...? And what exactly they base that on?
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#8 Josh Bass

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Posted 17 May 2009 - 01:49 AM

I bought my first camcorder in 2002, and this was still the conventional wisdom. It wasn't necessarily "don't use Sony" so much as it was "don't mix tape brands." They say to find a brand you like and stick with it, since the stuff can mix between the different brands and cause problems. I've heard the different grades of tape (most miniDV brands have several different "levels" of quality you can choose from) can have this issue.

Some say myth, some swear they've had issues when they mixed brands. Who knows? Until it's proven one way or the other, if you own the camera, why not play it safe and choose a brand and stick with it. Just try not to get into emergency situations where you need tape but no one who has your brand is open 'cause it's too late in the day/the weekend/whatever.
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#9 Karel Bata

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Posted 17 May 2009 - 06:55 AM

But is there any real difference in the differing 'quality levels' of tape? Or is it just marketing hype? For instance, what's the diff between min-DV and HDV? Many folks would say none, since the only difference is in the way the data is coded - everything else is identical. So just buy cheaper mini-DV tapes.

My suspicion is that no tape manufacturer wants to come out and say that their tapes are no different from anybody else's. And I bet all the brands are made in the same two or three factories!

This air bearing thing makes me wonder. You see I remember the days when a U-Matic would 'disengage' it's heads after five minutes and switch to EtoE. Or maybe I had all that badly explained to me. So if there's no actual contact with the tape, then there should be no tape wear while it's in pause...?

FWIW I stick to cheap TDK. Use once, then put in a sealed plastic bag in the basement for my kids to find when I'm dead. :blink:
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