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Old July 1st, 2003, 09:03 AM   #1
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Is it possible for dirty heads to contaminate tapes?

My friend recently had a problem with his XL-1s. All the footage from his camera on our last wedding was ruined by graphical artifacts. In an attempt to retrieve the footage he bought an inexpensive Sharp DV cam to use as a deck to avoid capturing from the dirty heads of the XL-1s.
It worked somewhat- we were able to salvage some footage off the tapes, where as none of it would have been salvagable via the XL-1.

Now he's using the camera again to capture footage shot with my GL-1 (on fresh tapes mind you)...and he's starting to get the same graphical artifact he did on his XL-1s. There's nothing wrong with the GL-1 so it's something to do with the play head on the new Sharp. Do you think running the tapes that were recorded by the dirty XL-1 in the Sharp contaminated the Sharp heads? And is this even possible for tapes to cross-contaminate?
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Old July 1st, 2003, 09:16 AM   #2
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Dirty camera heads are caused by problematic tapes in most cases (other causes can be dirty operating environments and misaligned or excessively worn heads). Problematic tapes could be defective in manufacture, damaged by shipping, storage, handling, repeated use, operating conditions and dozens more possibilities. So, yes, the tape was probably the cause of the XL1 heads getting dirty and now the tape is causing contamination of the Sharp DV camera and probably any other camera you put it into.
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Old July 1st, 2003, 09:34 AM   #3
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It's quite interesting you mention that because that would make a whole lot of sense- the defective tape part that is. Only once before did he have any problems with his recordings, but was cured easily by simply running the head cleaner. This time we figured it was the same thing but the head cleaner didn't even dent it. Mabye it was a bad batch of tapes- that is possible right? Now if that was the case how are they bad- in other words how would they "dirty" the heads. Would the tape have some sort of contamination from the factory. Oh and they were Sony tapes- which I've heard, once, that they have been known to have "bad" batches. I'm so inquisitive because I've heard things here and there but never knew the hard fact about these allegations of "bad tapes" ect. I didn't know if that info was true or just rumor.

Lastly the thing that concerns me most is the fact that now some of the tapes that were originally fine now play crappy even after running the head cleaner in the sharp. Does that mean that the contamination from the original tape spread to the sharp then to another, fresh, tape?! If so how do we get around this- you can clean heads but not tapes right?!
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Old July 1st, 2003, 09:56 AM   #4
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There can be many causes for problem playback. Have you ruled out mixing tape brands?

Defective batches of tapes are rarely possible, if ever. Quality control measures from any of the name brands would preclude an entire batch of bad tapes. I would be suspect of no name tapes of Chinese origin though.

A box of tapes can be damaged in shipment (heat, humidity, dropping etc.), Storage (same). Manufacturing defects can include defective shells (molded improperly, defective assembly), and defective tape (bad coating, defective in loading into shell).

Heat and humidity play a big part in damaging tapes. Grey market tapes and their shipment to US is a cause of concern. Tape manufactures take necessary precautions to insure proper shipment of their tapes to the US (many are made here). Grey market importers just ship by cheapest route with little care for the goods shipped.
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Old July 1st, 2003, 11:10 AM   #5
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Well how could a tape if damaged in the ways you described "dirty" camera heads? I have ruled out brand mixing because my friend specifically sticks with one brand (Sony Premium).

Now I'm worried because I ordered 20 Panasonic MQ tapes from TapeStockOnline- they are being shipped from CA. to NJ. (where I live) via UPS. I know darn well how UPS handles their goods- UGH! Plus the fact their trucks are very HOT and HUMID! Should this be cause for alarm regarding the tapes I'm going to be recieving this week?
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Old July 1st, 2003, 12:53 PM   #6
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Depending on the type of tape (Metal Particle, Metal Evaporated or Oxide) the magnetic material is bonded to the tapes polymer backing. Excessive heat, humidity can cause the magnetic material to loosen and pieces to flake away from the backing. The loose material is further weakened by winding through and across the many posts, capstan and other parts in the camera and cassette. The metal particles can attach to all or part of the video record, playback and erase heads. The clog may be for a brief instant or may require professional cleaning. In any event the signal may not record (dirty record head) or may not play back (dirty playback head) or leave a latent or residual image (previously recorded image not erased fully).

In most cases normal shipping is not a problem. But excessive heat and humidity during the summer months, especially in the southern climates, can create problems. Inspect the tapes carefully for obvious external damage to the shipping box and the cassette itself. If something looks amiss contact the shipper and retailer immediately.

I fast forward and rewind every tape before I record on it. Do a search on this I have posted several lengthy replies on this topic. Do not use tapes more than once. Keep the playback of the original recorded tape to a minimum. Repeated fast forwarding, rewinding and pausing is just asking for trouble. The tapes can stretch and you'll have a whole new set of problems.
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Old July 1st, 2003, 01:12 PM   #7
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Here's an odd one- I specifically remember when we we were watching the footage in the Sharp and switched tapes, the beginning of the next tape had digital artifacts in which you could see the image from the last tape! What would cause that?! Reminants of magnetic material from the other tape on the heads? It was so bizzare because we couldn't explain it beings theres no sort of buffer in-camera, that could cause such a problem. It had to be something physically with the tape.

Before I try and trudge through articles on here to find your posts is there a basic explanation for ff and rewinding a tape before using it? Is it something to do, simply, with tape slack? How will this benefit me when I actually go to record on it?

Lastly, when I recieve them and the box doesn't look damaged and the tapes "look" pristine, how do I know they weren't damaged from heat....does it always show visible physical wear?
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Old July 1st, 2003, 01:39 PM   #8
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The residual or latent image you saw was the result of a dirty playback head or heads. Similar images occur when the erase head is partially clogged and a tape is reused. During recording an incomplete erasure occurs and a mix of old and new recording is seen upon playback.

Fast forwarding and rewinding allows the tape to have equal tension and lay flat. It also allows loose particles to dislodge from the tape surface and minimize their exposure to the various heads.

The only way to guarantee with near 100% certainty that your tapes are fine is to record black on the new tapes and watch the playback for any abnormal effects. In most instances if the tapes were hot enough to cause damage there would be some signs, wrappers look distressed, cassettes not loading quite right (tight fit would indicate shell is wrapped from heat). If you're worried that the tapes might be damaged, record black on one tape and watch the playback. If it got hot enough to damage one tape it would probably effect the whole box (unless you ordered a pallet).
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Old July 1st, 2003, 02:11 PM   #9
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Hmm, so apparently the bad tape from the XL-1 gunked up the brand new Sharp! I never knew tapes could cary that kind of contamination...especially is used properly. Now will the cross contamination from the dirty XL-1 tapes onto the Sharp heads threaten any new tapes that are inserted into the Sharp? In other words when supposed "good" tapes play in the Sharp...and look pixilated...is that because of the dirty heads or does that mean the tape is now contaminated.
If the tapes that were played in the Sharp after being contaminated by the bad XL-1 tapes are also contaminated....can that be reversed or is the footage off the new (good) tape now BAD.
I'm sorry if I'm a bit redundant in my questioning I'm just a bit stressed about this and am trying to get the best grasp of it. Me and a friend were doing good getting our wedding video business off the ground only to be slammed with this problem. I appreciate all your input- thanks in advance!
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Old July 1st, 2003, 09:46 PM   #10
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The error correction (pixilation) could be caused by the tape being damaged or defective. It can also be caused the heads on the playback unit being partially clogged. It could have been recorded that way to begin with because the record heads were partially clogged. There is no way of knowing with a little detective work.

You'll need to try the playback in several units to see if it clears up. You might also want to stop the tape at the point if pixilation and visually inspect the tape for damage (creases, wrinkles, scratches etc.). If the tape is physically damaged there is little you can do. If the tape is recorded that way, there is also little you can do. Best case scenario is the tape is fine and the heads on the playback unit are partially clogged.

I read one of your post about using a rewinder. I don't recommend their use. Most rewinders run a full speed until the end of the tape. The abrupt snapping at the end of the tape can stretch the tape and cause problems. Rewinders also tend not to pack the tape as evenly as the camera.
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Old July 2nd, 2003, 08:23 PM   #11
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Wont fast forwarding and rewinding in camera wear out the heads....or does the tape not even run over them while in ff and rewind? Also wont it wear out the tape transport mechanism much faster?!
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Old July 2nd, 2003, 09:43 PM   #12
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Good rewinders will both FF & Rewind tapes. Not certain if the available DV rewinder will do this.
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Old July 2nd, 2003, 11:38 PM   #13
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I have never seen a recent tape transport worn out. They are all direct drive, and you're just not going to wear out the gears. I'm not saying tape transports don't get replaced, they do. But they are replaced because they get bent or misaligned because of careless handling, not FF and REW tapes. Some cameras my have the tape in contact with the heads during FF and REW, most don't.

I've seen mini DV rewinders the FF and REW, but they don't slow down near the end of the tape. They all snap the tape, which I view as a problem area.
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Old July 3rd, 2003, 05:49 AM   #14
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Do you know if the DVX100, in particular, has the tape in contact with the heads while rewinding/fast forwarding?
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Old July 3rd, 2003, 08:21 AM   #15
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I don't know, I'll try to get one of the people I know that has a DVX100 to look, or you can ask in hte DVX100 forum. Steve might know.
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