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Old November 2nd, 2006, 06:32 PM   #16
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Quote:
Originally Posted by John Vincent
I believe that for those who use Sony tapes that their head cleaners use a different method ("wet" vs "dry").
Hi John. Are you sure about this? I thought the wet and dry referred to lubricants on the video tapes themselves, and were nothing to do with the cleaning tapes. Would be good to get a definitive answer to this because it comes up every now and then.

Richard
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Old November 2nd, 2006, 07:10 PM   #17
 
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In more recent years, makers of tape and the lubricants used have standardized such that the gum formed by cross mixing tape brands has all but gone away.
On the subject of Fast Forwarding and rewinding a new tape, this is done to get all the loose recording material out of the tape where it is sandwiched between the tape layers on the reel. When DV tape is manufactured, the process, beleive it or not, is quite dirty. A lot of the recording oxide flakes off and gets trapped between the layers. The loose material then finds its way into the tape transport on your camera.
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Old November 3rd, 2006, 03:09 AM   #18
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I got into talks last time I was at JVC updating my HD100 with the technician.
I asked him honestly what is the deal with Cleaning Tapes? He said using the cleaning tape regulary 10 sec every 5 tapes is better for the head then having dirt stuck inside the video-heads due not cleaning enough. With the result that the cleaning tape cannot clean it anymore.
He said, doing that will give you more lifetime of the head that way. He could not count the video-heads he already replaced through the years due to people think in their mind the cleaning tape is a kind of scratching device. Of course if you run the cleaning tape over and over it damages the heads.
He also adviced not to use the first minutes of a tape for important footage. I always record a lead-in with colorbar the first 3 minutes.
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Old November 3rd, 2006, 11:02 AM   #19
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Quote:
Originally Posted by Richard Hunter
Hi John. Are you sure about this? I thought the wet and dry referred to lubricants on the video tapes themselves, and were nothing to do with the cleaning tapes. Would be good to get a definitive answer to this because it comes up every now and then. Richard
Nope, not sure. But I have read, on this site and over at DVXuser, at least a few posts where people came to bad ends using different brand tape cleaners. Bill Ravens is undoubtedly right when he says that the brands are becoming more alike and that there is far less danger in mixing brands.

But all most every thing I've read or advice I've heard says to stick to one brand of tape once started and then to use their cleaner. I do believe that the wet/dry aspect is relevant simply because you'd think there would be a (slight) difference in how the cleaner actually works.

The heads on these cameras are very small of course, and from my own point of view, I don't want to take any chance on upsetting what is already a fairly delicate process. But I make full-length films - I have the time for this - for run & gunners, it might not be so easy.

As for FFing a tape, it does seem that doing it in a 2d unit-type camera would be best, as the 'dirt' would be stuck there and not in the main camera. The three minute lead-in is also very good advice... Good stuff guys.
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Old November 8th, 2006, 07:39 AM   #20
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There is no real cure for this. Dropouts will always be there (as long as we're using tapes) - you can only minimize the frequency. Just as stated by most others:

1) Always new tapes
2) Never re-use tapes (that's the same... but you get the point)
3) Always use the same brand - due to possible different lubricants and slightly different tracks

I also FF to the end of the tape and REW to the beginning again.

It is all a matter of 'just to be sure', because there are always some dropouts (just not 10 in 1 tape).

The (small) SONY DVCAM cassettes are all I use. Not because of the brand, but because that are the only ones that feature a dust-proof case.
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Old November 8th, 2006, 06:53 PM   #21
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but is this normal?

so, let's say i just shot a 6 hour session with greenscreen and my footage is RIDDLED with these dropouts and artifacting. am i just hosed?!! this sucks because i did just shoot the above and it has a ton of artifacts and dropouts!

camera has less than 30 hrs on it, brand new JVC ProHD tapes...

previously, we had shot some SD footage using the recommended panasonic AY-DVM83MQ tapes.

is this normal? so, when shooting with this camera, do you just have to hope you're getting good footage without dropouts and artifacting?!

not only that, but i can't get the footage into FCP without it splitting all of my clips randomly.

i need help...

arg.
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Old November 8th, 2006, 07:29 PM   #22
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Quote:
Originally Posted by Eric Kome
so, let's say i just shot a 6 hour session with greenscreen and my footage is RIDDLED with these dropouts and artifacting. am i just hosed?!! this sucks because i did just shoot the above and it has a ton of artifacts and dropouts!

camera has less than 30 hrs on it, brand new JVC ProHD tapes...

previously, we had shot some SD footage using the recommended panasonic AY-DVM83MQ tapes.

is this normal? so, when shooting with this camera, do you just have to hope you're getting good footage without dropouts and artifacting?!

not only that, but i can't get the footage into FCP without it splitting all of my clips randomly.

i need help...

arg.
I hate to say it but you'll not get your footage back if it's riddled with dropouts. The tape you list (Panasonic) is definately not recommended for your JVC, nor is any 83 minute tape.
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Old November 8th, 2006, 08:18 PM   #23
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I wrote this some time ago but it relates to this discussion. Sorry about its length but it does describe what is happening during recording and playback.

The error indicator "Head Clog" is a generic data error rate indicator. This means that all data related error conditions are reported with the message “Head Clog”, not just when there is debris on the heads. Therefore, some people think this is a common problem when that really isn’t the case.

The message head clog or “use cleaning tape” is generated when the total data error rate is greater that a pre-determined threshold. The threshold is set to occur approximately when the error total would create artifacts in the image. But remember these errors occur and add up during recording AND during playback. So sometimes you see the artifacts without the head cleaning message.

The error rate you see during recording and/or playback is the TOTAL of the errors from 5 aspects of the record process:
Electronic or physical conditions
Dirt on the heads
Alignment of the tape
Tensioning of the tape
Condition of the tape itself

Just to give one example of how it works, imagine your camera is not perfectly aligned but is just within specs. This creates an error rate that is not visible. But if this camera then encounters just a small bit of dirt on the heads it will have artifacts during playing back the weaker portions of the tape. During service the technician checks for all 5.

1. Electronic or physical condition - It is possible through wear, pre-mature wear, or fault for one or both heads to record or read the tape signal with less than proper electronic signal strength. This results in more errors.

The electronics which read and amplify the data from the tape can have faults which result in their providing a weaker signal from the heads and this can increase the read error rate.

Head cleaning will not effect such a thing.

2. Actual contamination on drum - There can be tape debris on the heads that reduces the effectiveness of the recording process.

Head cleaning can take care of this.

If the head clog error returns, there could be a defective cylinder surface eroding the tape surface or the tape could be defective. Try another tape. If it happens on a few tapes the camera needs service. This is where the cleaning tape clears it for a short while but then it comes back and the cleaning tape clears it again but only for a short while.

3. Tape alignment problem - If the tape isn’t going through the mechanism with the proper alignment, the RF envelope will be poorly shaped (don’t ask). This will create data error rates that are too high and the head clog message will come up. No amount of head cleaning will help an alignment problem. The camera must be serviced.

Note that this can occur when you stop recording and the tape backs up and does a review. If the tape isn’t positioned properly as the review is performed you will get a head clog message but it is due to the tape alignment error rate not dirty heads.

4. Tape tension - The “mating” of the tape and head drum must be very precise. If the tape tensioning arms lose their ability to hold the tape closely and smoothly against the drum, the error rate will climb creating a high error rate and therefore the Head Clog message.

Possible causes are weak springs, evaporation of mechanical lubricant so the tension arms don’t move smoothly, and guides that aren’t perfect or are worn.

The head cleaning tape has no effect on this. This type of problem could happen at certain places on a tape as the tape reel diameter changes, causing a change in the “tension environment”.

Also this "mating" is improved if the same type of tape is always used.

5. Tape - A tape can be defective and have an area of lowered recording ability. A tape could also have picked up a tension bias during manufacturing that causes it to go through the mechanism in a less than correct path. And every tape has a bit of variation in its recording ability along its length.

It isn’t possible to tell which single condition is causing a given Head Clog message.

It is interesting to note that if we had used different error messages to indicate the above different conditions, the “head clog” message would only occur less than a fifth as much and no one would ever discuss such a thing as a “head clog” problem.

For most consistant tape operation we recommend:
Using 63 or 30 minute tapes, not 80 minute tapes. And if course you should never use LP.
Don’t switch tape brands, pick one you like and stay with it.
Use a head cleaning cassette from the same manufacturer as the tape you use.
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Old November 8th, 2006, 08:30 PM   #24
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Quote:
Originally Posted by Stephen L. Noe
I hate to say it but you'll not get your footage back if it's riddled with dropouts. The tape you list (Panasonic) is definately not recommended for your JVC, nor is any 83 minute tape.
awesome. these were the tapes that were recommended to me when i bought the camera from tapeworks.

so, the JVC ProHD M-DV63PROHD, these are ok to use?

so what exactly would my problem be? using 2 different tape manufactureres back to back? gumming up hte heads? and if so, would a head-tape cleaner fix this? i've got another big shoot this saturday, and i got to get htis figured out...

man, i feel like i've just been the victim of a very cruel (and expensive) joke. i'm sure i'll laugh about it months from now...

again. arg.
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Old November 8th, 2006, 08:32 PM   #25
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oh, and if it's the tape-head cleaner, can someone recommend one for me?

i'd be greatful.

and, when shooting SD, what is the recommended tape?

thanks
e.
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Old November 8th, 2006, 11:57 PM   #26
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Quote:
Originally Posted by Eric Kome
oh, and if it's the tape-head cleaner, can someone recommend one for me?

i'd be greatful.

and, when shooting SD, what is the recommended tape?

thanks
e.
Eric,

We recommend the MDV-63PROHD tapes for both SD and HD recordings. If you use these tapes, then also use a JVC DV head cleaning tape. They are economical enough to use for both applications.

As others have already said, DO NOT use any tapes longer than 63 minutes.

Also: Many customers purchased our DR-HD100 series hard drive recorders to augment their cameras. The tape issues are then eliminated, your record time goes up by several hours, and you save much time in the capture/editing process.

Regards, Carl
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Last edited by Carl Hicks; November 9th, 2006 at 06:55 AM.
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Old November 9th, 2006, 12:02 AM   #27
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Eric it is ok to use JVC and Panny tapes because they have the same lubricants, mixing Sony and some other manufacturers tape is wrong because Sony is the only brand with a different lubricant. Do not use 83minute tapes because the longer tapes have less tension and the film inside it is of lesser strength, they stretch. I would strongly recommend the Pro-HD tapes, I would have started with them from the beginning but they are very hard to find and if I run out of tape between takes you can't go down to the local store to pick 1 up. I have from the beginning used Sonys' HDV tape and have not failed me.
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Old November 9th, 2006, 08:47 AM   #28
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thanks guys. i'll run the tape cleaner through, and hopefully will fix things for my next shoot.

i appreciate everyone's help on this board. i've learned loads.

e.
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Old November 9th, 2006, 04:24 PM   #29
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Hold The Phone!!

SOOOoooo. just out of curiosity, i took my drop-out ridden tapes back to the camera, and viewed it on my HD monitor. guess what? no drop-outs or artifacting.

so, the problem i'm having (which looks identical to the jpeg that started this thread), appears to be with the BR-HD50 deck and not my tape, or tape heads in the camera. this makes me very happy that i don't have to reshoot! but, am not excited about capturing hours of footage on the camera either.

is it possible i'm just missing a settting or something on the deck?

by the way, i also tried batch capture in FCP with the camera, and there were no problems with the clips being split up.

thanks.
e.
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Old November 10th, 2006, 06:06 AM   #30
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Just clean the deck now and see if it still happens. By the way, does it also occur when you play back other tapes (shot at a different time) on the deck?

If the deck is really dirty and gives this kind of errors I wouldn't use it again before it had a torough cleaning...
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