DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Open DV Discussion (https://www.dvinfo.net/forum/open-dv-discussion/)
-   -   mysterious fluctuating tape dirt (https://www.dvinfo.net/forum/open-dv-discussion/17621-mysterious-fluctuating-tape-dirt.html)

Federico Martini November 26th, 2003 10:26 AM

mysterious fluctuating tape dirt
This is my PAL setup:

1997 XL1
2001 XM1 (GL1)
Miller DS10 tripod
Boom+directional Sennheiser+Rycote
Lowell Rifa light 1000W

1997 DSR-20P
Titanium1Ghz+FCP (begun w/PromaxG3+Premiere)
2 LaCie 500GB FW discs (very recent)

I've been working with this setup for several years now, moderate use. Mostly commercial, short things to pay my bills. This year I finally got the opportunity to make my first feature documentary and put to use my humble somewhat beatup setup in something I really liked. The cameras were both working perfectly. So was the deck. If I ever got a drop, headcleaner and back to normal.

Since day one, I must have used around 60 Sony Premium or Excellence tapes with the cameras. Probably half of them about 2 or 3 times. No problem. I couldn't avoid using the non-Sony tapes that came with the cameras or that a client bought. No more than five. Still no problem. No adversary lubricants sign.

Of course the problem comes now, after I shot 75 hours of brand-new Sony Premium for my doc. I don't think the heads of cams and deck needed to be sent in yet. The deck has only @ 800 hours of head use. My theory, during the shoot, was not to watch anything until back home. Wanted to capture the whole tape in the first pass. The XM1's head died in the middle of the trip. The older XL1 kept going.

When I got back from this month of shooting out in the country (very dusty and humid province of Corrientes, Argentina) I popped those minidvs in the DSR20 just to check a few. Sound was fine. I find video drops galore. Squares and rectangles here and there. They repeated in the same spot but they weren't recorded!!! If played frame-by-frame, they were not there. The drops only appeared if played normal speed. Played back from the XL1 made it even worse.

I took a couple of these droppy tapes, in representation of the others, and checked them in other DVcam decks and cams, the same thing happened. My deck was not the problem. After this tour of decks with the same tapes, I stick one of them back in my deck: in play, out of all the drops in the hour, only 2 appeared. The tape was cleaner? It miracolously improved at least. Happy, I decide the problem is gone and I can capture the 75 hours on to 2 LaCie 500gig discs. Tape 01 is fine. Tape 02 is full of audio drops. So are subsecuent ones. Audio drops and comes back up. I notice that the parts of the tapes that were played a couple of times are OK. No video nor audio drops.

The only conclusion I can approach to is that the tapes have a lot of dirt, particles or whatever it is, moving in there, and that they (the tapes) need some good cleaning, in order to be able to use the material.

Now the question is HOW TO CLEAN THE TAPES?

One way would be to play all of them a couple of times in my deck. Just PLAY or in fast SEARCH? Is it the same?

Or is there another way to clean them that won't leave all that dirt in my deck's head?

Specific answers highly appreciated.

Federico Martini November 26th, 2003 03:13 PM

I have to add that I have tried some tapes with the recently maintained XL1 and with someone's VX2000. On the XL1 the both audio and video drops persist. On the Sony only very few. This shows that the drops are not recorded. They show up or not depending on the head that reads them.

Should I go to a post house have them read (and captured) by a big DVCAM deck? Would a heavier deck have less issues with these problematic tapes?

Frank Granovski November 26th, 2003 04:27 PM

Some story!

I don't know if the tapes themselves can be cleaned without destroying some of the 1's and 0's.

I don't consider myself a pro, shooting is more a hobby for me. But I am ALWAYS careful with:

1) sticking with 1 tape brand/type (Fuji)
2) keeping everything dry and clean, which means covering the cam in dusty or wet conditions. Saran Wrap or a Zip-lock bag works for me. When the cam is not in use it goes back into my cam bag.

Federico Martini November 26th, 2003 04:54 PM

Of course I'm not thinking of grabbing a cloth with alcohol and wiping the tapes. I notice that, when played several times in my DSR20, the tapes tend to improve into minimal dropping. But the deck must collect the residues, I guess. And maybe then spread them in other tapes. So I thought there might be some mechanism to play the tape over a head that accumulates the dirt without spreading it on to others. Something like a tape rewinder with extra cleaning capabilities.

All times are GMT -6. The time now is 09:27 PM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2020 The Digital Video Information Network