OT: "All Tapes Blank?" paranormal activity

Okay,

I have a tape case the sits to the right of my desk. It is at least 2 feet from anything electrical.
They hold the master footage to all projects over the last 6 months. I have a broadcast monitor and often there are 4 or 5 tapes sitting on it.

Today, I grab a tape from off of the monitor and stick it in my cam. Then apple-8 to capture and there was nothing on the tape. So i tried a different cam ( the originating cam) and there was no TC on the dv tape. ( thats 2 cam that see nothing )

ok, fine, i try another tape. Dido happens 2 cams so i try a 3rd. Dido

In fact i tried 4 different tapes from 4 different storage locations and all 3 cams and see nothing.

2006 - no tc
2007 no tc
april 2009 - nada

ON 3 CAMS
Is this the twilight zone or what?

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

Dido .... as in perform mischievous tricks?

Sorry to say, but a broadcast monitor is just a giant electromagnetic field generator. Keeping the tapes on top of the monitor degaussed them. The information has been erased.

There's no mystery here. Not putting tapes on top of monitors is pretty much film/video school 101.

i didn't get my monitor until 07ish, Before then it was a tv. Also i have a mat made for that purpose on top of my monitor (1.25 inches thick). I sat one just behind a 15 inch speaker back in 04. It erased everything and i have been paranoid since.

however, they did start playing after driving 1 hr to get my friends camera, some air and a tape cleaner session. They still don't play smoothly in the beginning. It has the blue stripes for 20 sec.s or so, then they matrix off in my little cam. the big cams play fine now and so does the tapes that were not on the montor

But this has been enough to tale debe's advice and don't trust the matt either.

Maybe i need to buy a new desk.

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

Sorry about your tapes, but insted buying a new desk, get something to close the tapes inside, like a small vault and put it in a temperature and moisture controlled place away from any magnetic fileds.
The money spended and your work are inside a little tape. So each tape holds sometimes a lot of $$$$$$

Rui Barros
Editor Colorist Trainer
Lisbon, Portugal
RTP Post-Production
Apple Certified Trainer FCP 7
Apple Certified Pro FCP 7

Dido ... the singer maybe?

i thought i had that.

I built stained hickory wood cabinet 5ft tall 3 feet wide then lined the inside with rubber. Then i drilled a 1.5 inch hole in the top and lower right hand side, then connected a small dehumidifier to it. It pulls air out of the side and that air is sent thru the dehumidifier and then air goes back in thru the top hole.

The doors have weather stripping and the tapes inside are all in cases (98% of them). It sits in an unfinished room on the other side of my basement at least 15 ft from anything electrical and 4 rooms away from the edit bays.

It might be dust is what i am thinking. I have been meaning to put some dust filters on it to some how filter the air going back in.

The vaults are quite expensive to put 23 - 48 count tape racks in but if this isn't good enough maybe i need to break the budget on something manufactured for this use.

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

I keep my tapes in a Good Quality plastic Ice chest-- No ice--
This keeps the tapes at a fairly constant temperature --

Store tapes standing on the ends -- long periods of laying flat
can cause the edges of the tapes to curl -- Jay--

Quote

Not putting tapes on top of monitors is pretty much film/video school 101.

...nuff said right there, deb.

When life gives you dilemmas...make dilemmanade.

Read the post.

Quote
joe
Quote:
Not putting tapes on top of monitors is pretty much film/video school 101.

...nuff said right there, deb.

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Corbett
In fact i tried 4 different tapes from 4 different storage locations

Also i have a mat made for that purpose on top of my monitor (1.25 inches thick)
i didn't get my monitor until 07ish,

2006 - no tc
2007 no tc
april 2009 - nada

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

I read your post corbett. I was talking to deb.

When life gives you dilemmas...make dilemmanade.

>Dido happens 2 cams so i try a 3rd. Dido

[en.wikipedia.org]



www.strypesinpost.com

Dido ... maybe that little fella off the 7up adverts

A broadcast monitor is no-where-near strong enough to degauss a DV tape...

I'm not arguing with you at all, Graeme. I'll believe pretty much near anything you tell me...but I do have to ask...

So do you have any idea where this originated, then? Because darn near every "old school" editor and engineer I worked with at a TV station or in a full-blown post facility has always told me to never put tapes on top of monitors or on the old Wacom-style tablets, in the case of the old Grass Valley Halo graphics system.

It must have roots somewhere, 'cos I got that lecture a couple times early in my career from guys who are smarter than I am when it comes to the techno-stuff. I just do what I'm told!!

Old Engineer's Tale, perhaps?

debe

According to WHO, a TV emits around 2.5 to 50 micro-Tesla at 3cm: [www.who.int] (that's 2.5 to 50 millionths of a Tesla)

1 Tesla is 10,000 Gauss: [en.wikipedia.org])

A degausser for video tape is from 2200 Gauss to 3700 Gauss, a lot less than 1 Tesla.

Now, monitors do have a degauss pulse when you switch them on. I don't have any figures on the strength of that. The purpose of that pulse is to remove the residual effects of magnetism from producing funny colours on the screen.

So yes, it's not good practice to allow magnetic tapes near monitors or other sources of magnetism. But I've never had an actual case of a computer disc, hard drive, or video tape being degaussed from a TV.

I love Mondays that are filled with geeky-goodness!

Thanks for the schoolin', Graeme!

debe

I come from that same old school education debe. One big difference back in the day is that all recordings were analog. Exposure to magnetic fields might not wipe out a tape, but over time could degrade the signal.

In the digital age you either have a bit or not. So you have to degrade the signal a LONG way to see errors. I have been told, tho have never tried it, that you can run a digital tape through an old school bulk eraser and they will still play. Not an experiment I would try with my master recordings that is for sure.

All told, by habit and training I don't leave tapes on monitors or speakers.

Back to the original problem. So there are tapes that were stored well and away from magnetic influences as well as those that were potentially erased. Yet none play? Do you get any input from any tapes? Sounds more like a signal path problem than blank tapes to me.

-Vance

Thanks for the additional info, Vance.

I'm one of the old-ish dogs. My career goes all the way back to mastering on 1". Hearing it in the analog days was certainly more common.

Like you say, I'm not going to run out and test it, either. It's still nice to know, though!

There was also a shift back in the end of Analog Superiority Days where the tape manufacturers liked to use the word "coercivity" in the ad bumpf. They has switched the magic formula that held the pixel pixies on the tape so that it required greater effort or "coercion" to move them, which is when bulk erasers got a little bigger and supposedly tape became less susceptible to inadvertent modification due to leaving them on top of monitors.
In my early days there were old timers who had worked on the early days of tape that had stories of dropping huge 2" reels and erasing random bits of them. But they also tried to get me with the ol' drop out collector bit (a soup can that collected the microscopic drop outs) and I was pretty sure a lot of what they told me was at the very least apocryphal.

The other reason to not leave tape near a monitor was due to the much more prosaic reason of heat. Pro CRT monitors have a faraday cage and huge power supplies and generate a lot of heat so a monitor isn't the best place to leave your master or your wallet, iPod, and headphones for that matter.

I am still trying to balance my network HDCAM masters on top of my LCD. Keepin' it old school, yo!

ak
Sleeplings, AWAKE!

Hold on a minute. The drop out bucket WASN'T real. Holy cow. It used to be my job way back when to go around to all the quad machines and empty those.

Interesting story about dropping the tape. I think your apocryphal take is dead on. However, If you take a hammer to iron you can magnetize it. Still, I have reservations about being able to randomize a tape by blunt force.

I can JUST get an HDCam tape to balance on my 30 Cinema Display. I hope no-one slams a door downstairs tho.

Well those 2" reels were huge, and almost all metal.

The second "welcoming" gift after your drop out collector was a complimentary box of bars and tone. That and leaving the tone generator on full volume and running out to see how long it would take the new person to hunt down the amp and DA and follow the patch cords to the source without taking anything off-air. Some people are jerks...

ak
Sleeplings, AWAKE!

About ten years ago I spent an hour scouring the tape room for the keys to the DVW-A500.

I never have forgiven the tape op who sent me on that little errand.

VPiccin

Most of the tapes play fine (90%). There are just a few with blue out at the beginning moving to blur horizontal lines then clean video. its mostly in the 1st 20-40secs of the 9 tapes i have found it on. Thank goodness for my pre-roll habit of 30s.

I believe it was dust. I recently (2 months ago) had the last 2 rooms in the basement finished. At least i hope thats what it was.

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

Humm these are DV tapes right? The usual symptom of a mechanical problem with the tape in DV is much of the screen will freeze with horizontal stripes of moving video. The stripes, which are about 10% of the screen height, will change positions as well. Basically chunks of data are missing and the buffer is holding on to the last stuff it had. This happens in blocks, but often presents as stripes. Is that what you are describing as "blur horizontal lines"?

If that is the case, dust could be the problem, or tape damage like stretch or crinkling.


-V

thats exactly what i am seeing.

last year it happened while we were filming from a helicopter. My theory for the occurrence is that as we enter the chopper the dust that formed from the propellers got into the camera.

the tape itself looks fine. No crinkly edges but in 1 tape i notice some very light grit or dust. It wasn't much just 3 or 4 grains/particles. However i believe this to be the main problem.

I am adding a dust filter today and building a smaller version of my 3x5x2 storage case with a plexiglass door for my desk to keep my tapes in. I hope sdhc will end this for me in july.

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

How "active" was the helo ride? In the mid '80's I worked on a project for the Air Force Red Flag exercises in Nevada. The producer and DP mounted a couple of Hi8 cameras in the cockpit of a fighter jet.

An air force pilot then took them for a ride. A real rocking 8G jinking and jiving hop over the desert floor at mach speeds. During the high G turns and pulls the tape mechanism couldn't hold the tape to the head drum and recording was lost.

I have no idea how much force it would take with a DV camcorder to dislodge the tape, but if your pilot was pulling G's that might have been your problem.

-V

Another important point is that analogue tapes are much easier to wipe than digital ones. The digital recording heads use a lot stronger magnetism to record the data.