timecode/blacking tape at DVinfo.net

Go Back   DV Info Net > The Tools of DV and HD Production > The Long Black Line

The Long Black Line
Tape, tape and more tape; and decks; HDV, DV, VHS and more.


Reply
 
Thread Tools Search this Thread
Old July 10th, 2005, 07:41 PM   #1
Regular Crew
 
Join Date: Nov 2004
Location: la, ca
Posts: 87
timecode/blacking tape

Is it the case that you can hit record (on a miniDV cam) with the lens cap on in order to lay down an unbroken sequence of timecode?

If so, does recording black reduce the quality of future footage you record over that black?

Thanks;/
Steve Watnet is offline   Reply With Quote
Old July 10th, 2005, 10:09 PM   #2
Inner Circle
 
Join Date: Jun 2003
Location: Toronto, Canada
Posts: 4,750
1- Yes.

2- No.

If you do a search here, you will find some posts about blacking tapes. If you are newer equipment and know your equipment well and know how to avoid TC breaks, it's probably better not to black your tapes.
Glenn Chan is offline   Reply With Quote
Old July 11th, 2005, 09:44 PM   #3
Regular Crew
 
Join Date: Nov 2004
Location: la, ca
Posts: 87
Thanks, Glenn.

Thanks, Glenn. You had an interesting post regarding generating new timecode for an existing tape using a 4pin-4pin firewire cable in the post "Do any of you "black" your tapes before using them?"; thanks for that.

There seems to be wide disagreement on the subject of whether blacking is or is not a good idea--a lot of people people seem to feel very strongly that it is a waste of time, destructive to equipment, blah blah blah.

For my part, I have had so much trouble "up-res'ing" offline footage that I never, ever want to deal broken timecode again. I've wasted far more time and energy on that process than could ever be wasted on blacking tapes. Further, with everything going on on in the field or on a set, the last thing I want to do is fuss with rewinding the tape. It seems like (please correct me if I'm missing something) that blacking tape is the simplest, as well as most definitive way of avoiding timecode breaks on one's tapes.

All of that notwithstanding, I'm still concerned about the head-wear question. People complaining about head-wear sounds suspiciously like something people repeat because they've heard it said, rather than because they've experienced the problem first-hand, but I'm just guessing. How much of a problem is head-wear, really?
Steve Watnet is offline   Reply With Quote
Old July 11th, 2005, 10:01 PM   #4
Inner Circle
 
Join Date: Oct 2004
Location: Port St. Lucie, Florida
Posts: 2,614
I'm not sure what you mean about "up-res'ing" off line footage, and how that relates to pre-blacking or pre-time coding the tape. In my tests on pre-blacked tapes, the time code was not maintained. What I mean is that, when I recorded to that same tape again, there was time code, but it did not maintain a continuous link. It droped or gained a frame or so from the previous record.

When you record on your tape, just make sure you don't go forward and start recording. If you do that, all will be OK! It is only in capture that you can have trouble, and as long as there is timecode, there is no major problem, except another scene. Why put two hours on your camera to record one hour of footage?

There are many threads here on that same subject.

Mike
Mike Teutsch is offline   Reply With Quote
Old July 11th, 2005, 10:22 PM   #5
Inner Circle
 
Join Date: Jun 2003
Location: Toronto, Canada
Posts: 4,750
Steve:

(working with DV)
Suppose someone gave you a tape with TC breaks on them. It's unprofessional for them to do that, but you gotta deal with it.
If you know the tape has a TC break on it, just dub it. Most equipment will generate new, continuous timecode. Some equipment has options to clone the timecode (i.e. DVX100a), which can be useful but not in this case.

Sometimes you aren't sure if the tape has a TC break on it or not. The following workflow wouldn't have a problem with that:
Capture the whole tape.
If it has a TC break, your program will likely report it. Delete the captured footage, dub the tape, and try again. Or put the captured footage onto tape, and then capture from that. **CAVEAT: FCP3 and before would lose audio sync if there were TC breaks, from what I remember.
Once captured, split the clip up using date/time DV scene start/stop detection.
Buy more hard drive space if necessary.

In some cases you can't do that, in which case you need to be vigilant about TC breaks and possibly look at blacking tapes.

2- Blacking tapes does add more wear and tear on your equipment. Video heads have to be replaced every few to several hundred hours on camcorders (consumer equipment may be less robust?). Decks last a little longer.
Such a repair costs several hundred?
Glenn Chan is offline   Reply With Quote
Old July 11th, 2005, 10:27 PM   #6
Regular Crew
 
Join Date: Nov 2004
Location: la, ca
Posts: 87
Mike, you've done exactly as I described and simply repeated something ("why put two hours...") without justifying the repeated statement with first-hand experience. Just like in those other posts you cited. You've actually managed to outdo yourself by repeating Glenn's point within the space of the same thread.

What I mean by up res'ing is when you capture at a low resolution so you can edit on a laptop or memory-poor computer. You know, like to save space and rendering time and to improve the response of your software?

What happens is this: when you re-capture the cut at full resolution, timecode breaks are a big pain. There are a lot of posts on the subject. You should read up on it. Further, when you shoot in widescreen, as I often do, up-res'ing provides yet a whole new dimension of problems relating to the dimensions of the frame (it distorts and shrinks the image). So instead of going from one hours to two (as one does with blacking), one goes from one hour to wanting to die. As I said, the "time-waste" complaint associated with blacking is, for me, moot.

However, my reality is that I can't afford a new deck or even cheapie camera to black tapes, so I'm trying to ascertain how bad blacking is for heads based on anecdotal evidence, rather than by counting how many times people repeat "blacking is bad". See the difference?
Steve Watnet is offline   Reply With Quote
Old July 11th, 2005, 10:37 PM   #7
Regular Crew
 
Join Date: Nov 2004
Location: la, ca
Posts: 87
Glenn,

You seem to be a proponent of not blacking tapes because:

1. equipment wear and tear
2. dubbing is a more definitive way of getting continuous timecode.

Just to double-check, no generation loss to speak of when dubbing from one cam to another (especially if one cam is cheap)? I don't know how the compression/data trasfer works in this case.

Quote:
Originally Posted by Glenn Chan
Once captured, split the clip up using date/time DV scene start/stop detection.
Buy more hard drive space if necessary.
What's the value of this, apart from having a complete backup of the footage?


(For the time being, I:

1. can't afford another tape deck/cam
2. often have to shoot with batteries, which inevitably die mid-tape
3. often can't even afford new tapes

However, at the risk of repeating myself, I need a solution to broken timecode. I assume, in my case, blacking would be the recommended course? Or is it the case that blacking tapes produces significantly more problems than rewinding to previous timecodes after turning off the camera or switching tapes?)

Last edited by Steve Watnet; July 11th, 2005 at 10:57 PM.
Steve Watnet is offline   Reply With Quote
Old July 11th, 2005, 10:56 PM   #8
Inner Circle
 
Join Date: Oct 2004
Location: Port St. Lucie, Florida
Posts: 2,614
[QUOTE=Steve Watnet]Mike, you've done exactly as I described and simply repeated something ("why put two hours...") without justifying the repeated statement with first-hand experience. Just like in those other posts you cited. You've actually managed to outdo yourself by repeating Glenn's point within the space of the same thread.

Man, I'm not sure but I think I should be insulted by a personal attack! I don't understand exactly what you are saying, with upresing, but you are dealing with 1s and 0s at the time of recording, and timecode should not have anything to do with how you download or capture it. Time code breaks do not have anything do to with how you record or what format you use. It is only a potential problem with capturing, and breaks. Upreses - downres, time code has nothing to do with it!

I give up!

Mike
Mike Teutsch is offline   Reply With Quote
Old July 11th, 2005, 11:17 PM   #9
Inner Circle
 
Join Date: Jun 2003
Location: Toronto, Canada
Posts: 4,750
Mike:
Steve might be doing an "offline" edit by capturing footage at lower resolution. Final Cut and Avid can do it.

I don't think he meant to offend you. (at least, I hope not!)

Quote:
2. dubbing is a more definitive way of getting continuous timecode.
It's not a more definitive way. It's just a way to rescue yourself from timecode breaks.

Blacking tapes:
A- takes time
B- adds some wear and tear
C- allows you the opportunity to accidentally overwrite footage. Happened to me. :( LABEL YOUR TAPES AND USE THE WRITE PROTECT TAB.

Quote:
What's the value of this, apart from having a complete backup of the footage?
I find it faster. It's a matter of taste.

Benefits:
A- fastest way of capturing.
B- Least button pushing for me. I take log notes on paper while you watch the capture go.
C- You never need to waste time recapturing footage, because it's already captured.
D- (minor benefit) Least wear and tear on equipment.

Quote:
(For the time being, I:

1. can't afford another tape deck/cam
2. often have to shoot with batteries, which inevitably die mid-tape
3. often can't even afford new tapes

However, at the risk of repeating myself, I need a solution to broken timecode. I assume, in my case, blacking would be the recommended course? Or is it the case that blacking tapes produces significantly more problems than rewinding to previous timecodes after turning off the camera or switching tapes?)
You don't need another deck/cam to dub tapes, depending on your editing system. If your system can capture over TC breaks:
capture the tape in one shot.
print the captured footage back to tape. It will now have continuous timecode.
Delete the captured footage, and capture off the new tape.
Watch out for preroll (it may be hard for your editing system to capture off the first few seconds), and FCP3.

Another option is to avoid TC breaks in the first place when you shoot. There are posts on this. Methods:
A- Use end search function on camcorder.
B- If your cam doesnt have A, manually rewind to the do the same thing. Take more time before you stop rolling camera.
C- Or black tapes.
D- Or never rewind to review footage.

If you can't afford new tapes then you might have a problem?
They're like $3USD in the US if you don't buy from a dvinfo.net sponsor. dvinfo.net sponsors are a little more. Tapes are cheap.
In any case, there are free solutions which I've mentioned above.
Glenn Chan is offline   Reply With Quote
Old July 11th, 2005, 11:30 PM   #10
Inner Circle
 
Join Date: Oct 2004
Location: Port St. Lucie, Florida
Posts: 2,614
Thanks Glenn!

Still don't fully understand what he is saying, but time code may be the least of his worrys.

Mike
Mike Teutsch is offline   Reply With Quote
Old July 12th, 2005, 12:24 AM   #11
Regular Crew
 
Join Date: Nov 2004
Location: la, ca
Posts: 87
Of course you should be offended, Mike! I hoping at least you would pause and say something considered. Objective not achieved!

But you did say something I found interesting:

Quote:
Originally Posted by Mike Teutsch
In my tests on pre-blacked tapes, the time code was not maintained. What I mean is that, when I recorded to that same tape again, there was time code, but it did not maintain a continuous link. It droped or gained a frame or so from the previous record.
Mike
There seems to be a variance of experience here. Some find blacking fixes their timecode problems. Others find that to be the case not at all. Why that discrepancy exists is not clear. It certainly isn't resolved anywhere I could see. It seems like the discrepancy can ultimately be rendered moot if you apply the technique Glenn described.

(To address your question, Mike, by up-res'ing I was indeed referring to editing in "offline" mode. The term "offline" has an ambiguous meaning--whereas the term "resolution" is more or less concrete.)

Unanswered questions:

- Is there some form of compression applied in dubbing footage that causes generation loss?

- What is the real world, qualitative result of tape head wear?
Steve Watnet is offline   Reply With Quote
Old July 12th, 2005, 12:46 AM   #12
Inner Circle
 
Join Date: Jun 2003
Location: Toronto, Canada
Posts: 4,750
Timecode discrepancy:
The discrepancy might come from the way drop-frame timecode works?
NTSC video runs at 29.97frames per second. The timecode counts up with 30 frames a second. To maintain a close relationship with actual running time, a few timecodes/frames are skipped every once in a while.
It might be possible for the tapes to be slightly off because of this?

It should be easy to test this out, but honestly I'm too lazy.

Quote:
- Is there some form of compression applied in dubbing footage that causes generation loss?
If you're transferring over firewire, the transfer is lossless.
*If you're transferring from camcorder to computer, there is the potential for the capture program to strip away some information (timecode, date/time, user bits). iMovie/Mac does this (definitely lose timecode; not sure about date/time and user bits), while Final Cut/Mac doesn't (as far as I know).
But video and audio quality remain the same.

Quote:
- What is the real world, qualitative result of tape head wear?
Your camera's heads will need to be replaced faster.
Glenn Chan is offline   Reply With Quote
Old July 12th, 2005, 02:25 AM   #13
Regular Crew
 
Join Date: Nov 2004
Location: la, ca
Posts: 87
Obsessing about heads, etc.

Very informative, thank you very much.

To beat a dead horse, have you ever:

1. noticed a difference in footage quality caused by worn heads?
2. replaced your heads because of it?

Bonus head questions: Are there separate heads for recording vs. playback? How much damage does does recording do to the tape heads vs. playback, roughly?

Last edited by Steve Watnet; July 12th, 2005 at 04:07 AM.
Steve Watnet is offline   Reply With Quote
Old July 12th, 2005, 05:40 AM   #14
Inner Circle
 
Join Date: Mar 2005
Location: Hamilton, Ontario, Canada
Posts: 5,742
Quote:
Originally Posted by Steve Watnet
Very informative, thank you very much.

To beat a dead horse, have you ever:

1. noticed a difference in footage quality caused by worn heads?
2. replaced your heads because of it?

Bonus head questions: Are there separate heads for recording vs. playback? How much damage does does recording do to the tape heads vs. playback, roughly?
Don't know if there are separate heads or not but the question is moot. It's the physical movement of the tape against the heads (actually since the heads are on a spinning carrier it's the movement of the heads against the tape) that causes the wear and not the signals involved in the act of recording or playback, thus the same wear will occur regardless of mode and it wouldn't matter if there were separate heads or one set doing double duty. If there were two sets, they would still be on the same carrier drum and in contact with the tape even if not being used. It even occurs when the deck is in "pause" as long as the heads are spinning.
Steve House is offline   Reply With Quote
Old July 12th, 2005, 10:23 PM   #15
Major Player
 
Join Date: Nov 2003
Location: ontario
Posts: 445
I was following this thread and wanted to say thanks for the input Mike
Jack Smith is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > The Tools of DV and HD Production > The Long Black Line

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 05:52 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network