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Old May 24th, 2007, 06:22 PM   #1
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Is there such a thing as contaminated tape?

If a camera with a misalignment, dirty heads or pinch rollers records pixelated or banded video to a tape, is that tape then contaminated? In other words, can that tape be used again in another known good camera to successfully record over that bad video or will all future passess recorded in that section of tape be bad?
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Old June 4th, 2007, 04:26 PM   #2
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Don't re-use that tape, you might damage the heads of your camera, especially when the previous recording device had a misalignment. Don't damage your gear to save a few bucks!
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Old June 5th, 2007, 02:31 PM   #3
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It's not about saving money. I just wanted to know if a corrupted tape could affect another camera. How could the data being recorded to the tape incorrectly damage another camera? It's just data, not hardware.
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Old June 5th, 2007, 03:40 PM   #4
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One might assume, that the 'corrupted' tape has bad data on it, because the heads were clogged with 'gunk' in the first camera. One might also ask if that 'gunk' was then deposited on the tape as it traveled through the tape paths. One could also posit, that such 'gunk' might be deposit on a NEW camera's tape path, once it is run through it.

If one were so disposed to assume such.

One might assume that the tape is corrupted, because of bad formulation, causing drop outs. Such a tape might continue to 'drop out' (IE Leave oxide particles) on the new camera's heads.

Just a thought. Not worth four dollars in my book.
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Old June 5th, 2007, 05:47 PM   #5
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Let me simplify this. If the camera is brand new out of the box and it has issues and records banded video, dropouts, pixelation on a brand new tape, will placing that tape in another known good camera harm that camera?
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Old June 5th, 2007, 05:52 PM   #6
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No way to answer that with one hundred percent certainty, if that's what you're looking for.

I'd say the chances are slim for 'cross contamination' from the scenario you've finally gotten around to outlining.

I'd also point out for the record, Canon recommends cleaning the heads as soon as you get the camera. (Xl2 Manual) Just what exactly might be on the drum heads shipped from the factory? Who knows. But they do reccomend it, so I'm assuming there is some element of the manufacturing process that deposits ... what? .... on the tape heads and path.

But my question still remains, is the possibility of transferring gunk from one camera to the next, worth the cost of a tape?

I'd also refrain from stating that it would 'harm' the camera. Dirty the heads? Yes, but they can be cleaned. Is that the same thing as harming the camera, or just plain wear and tear? And to answer an earlier question, it's not the corrupted data that carries the contamination, it's the contaminant that corrupts the data that might POSSIBLY be transferred via tape from camera to camera.
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Old June 5th, 2007, 06:20 PM   #7
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Originally Posted by Richard Alvarez View Post

But my question still remains, is the possibility of transferring gunk from one camera to the next, worth the cost of a tape?
And my answer still remains, It's not about saving money. I just wanted to know if a corrupted tape could affect another camera. How could the data being recorded to the tape incorrectly damage another camera?

I have 4 XL-1 systems all bought new at the same time. The one I have used the most finally started acting up, as expected, causing the errors described earlier. Well, I put that tape with those errors in camera 2 which has very few hours on it and shortly after it started having the same issues as camera 1. Then I put a new tape in camera 2 and it still had those issues. I am now using camera 3 with very little hours but only with a new tape and not having used the original corrupted tape at all. So far there hasn't been any issues. I don't know if it's an unlucky coincidence or if that first tape was corrupted by the first camera and has caused the second camera to go bad. If the third camera goes bad in a short time since I started using it, I'll have one more camera to go. If the last one goes bad in a short time too, then it's possible that Canon has a timer in the firmware that forces an owner to send it in for maintenance after a set time with or without heavy usage!

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I'd also refrain from stating that it would 'harm' the camera. Dirty the heads? Yes, but they can be cleaned. Is that the same thing as harming the camera, or just plain wear and tear?
What?! Anything that would make a device malfunction is harming that device.
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Old June 5th, 2007, 07:36 PM   #8
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"What?! Anything that would make a device malfunction is harming that device."

Well, by that definition, using the device 'harms' it.

Look, tape heads and paths get dirty over time. That's why it's always good to clean them before an important shoot. (Some arguments about 'regularly' vs when needed... but the point is, you have to clean them every now and then.)

That's NORMAL WEAR AND TEAR - heads getting dirty through use, needing cleaning. Heads WEARING OUT after a lot of use, so by your definition USING the camera harms it.

YOU WROTE: "And my answer still remains, It's not about saving money. I just wanted to know if a corrupted tape could affect another camera. How could the data being recorded to the tape incorrectly damage another camera?"


I don't know what answer your looking for. I explained that yes, contaminants can be carried from tape to camera. I explained its the contaminants, and not the contaminated DATA that is the problem. I explained that the chance of transfering contaminant to a BRAND NEW camera and contaminating it was slim... (only my opinion mind you.) I explained the Canon reccomends cleaning heads of BRAND NEW cameras before you use them.

It sounds like you have two cameras with dirty heads. I assume you have run tape head cleaners through them, and had no results? Then send them back to Canon for repair. It happens. Stuff gets in the gears/paths/heads when we aren't thinking about it.

I know. I just got my entire drum assembly replaced. They did a great job.
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Old June 6th, 2007, 12:28 PM   #9
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What I meant was that a somehow damaged tape, especially one that has been crumbled by a misaligned head/tape transport can actually damage the video heads in a perfectly good device. And, as said before, dirt and gunk from one bad/old device can be transferred to a good device via the tape.

Our repair technician always warns us not to re-use tapes that have been corrupted in only the slightest way. You dropped a tape on the floor: dump it. A tape showed visible errors during playback: dump it
In his opinion even re-using tapes more than 10 times or so can damage video heads in the long run. This guy is really good and he has seen it all (he repairs a lot of stuff from low budget productions and regional tv stations) and he owns a small eng truck which he designed and built, so he's not talking from an ivory tower. I have no reason not to believe him.
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Old June 6th, 2007, 09:31 PM   #10
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One thing that I didn't mention that happens with camera 1 and 2 is that they both record fine in VTR mode via Firewire. I wonder why that is? Both of them also have playback issues with video recorded through the lens but no issues with playback of video recorded via Firewire. There isn't a different circuit for recording through the lens and through Firewire is there?

Heiko, thanks for your info. I'm sure that your tech is competent but he's not the only one that's been doing this for a while. There are plenty of worthy techs in the Atlanta area as well as other cities anywhere. It's not hard to build an ENG truck either, I have a 4 camera truck package myself. I've been doing this a while too and luckily have had no issues up to the last few months with these cameras.

Camera 1 has been a workhorse traveling with me everywhere I have gone and has performed very well with a few hundred hours on it so it's about time for it to get serviced. I noted the details of what happened earlier so maybe it's just a coincindence that camera 2 started acting up or maybe it did get screwed up by using that tape after it was used in camera 1. I cleaned the heads in both and that didn't fix either of them so I will have to send them off eventually. So far there haven't been any issues with camera 3.
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Old June 8th, 2007, 01:14 PM   #11
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Quote:
There are plenty of worthy techs in the Atlanta area as well as other cities anywhere.
I didn't mean to imply that there are no other good techs :)
All I wanted to say was that this guy really knows a lot about recorders and video heads and he told me to be extremely careful with damaged or dirty tapes... and that he's not some freak who only repairs stuff (and might therefore be overly sensitive) but also works in daily eng productions.
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Old June 8th, 2007, 06:21 PM   #12
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Originally Posted by Heiko Saele View Post
I didn't mean to imply that there are no other good techs :)
Okay, okay, I meant what you knew.

What's so aggravating to me about this is that my other 3 cameras have less than 40 hours on them and this shouldn't be happening with such little usage.
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Old June 8th, 2007, 10:06 PM   #13
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Yup, "shouldn't" but it is. Could be a number of issues not just 'dirty heads'. Could be dirty heads on one, bad tape tension on another. But the only way to know for sure is to send it in. TEST it when it comes back too. C
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Old June 14th, 2007, 12:55 AM   #14
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Perhaps the first camera's tape path alignment is putting a microscopic "dent" onto the tape, so when you put the videotape with the indentation into the next camera it is wreaking havoc on the next head drum, and so on and so on.
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Old July 11th, 2007, 06:25 PM   #15
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Here is a relative thread that discusses the probable cause of this problem.
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