Stripping/Blacking Tapes For Z1P

[Chris Hocking]

Hi Everybody,

I've been doing a bit of Googleing tonight and I still can't seem to find an conclusive answer to this question.

I have been told by some Z1P gurus that you should always strip/black your tapes before use (meaning, record "nothing" for the complete duration of the tape). The theory behind it is that by doing this you record timecode onto the tape, and then when you film your "proper" footage at a later stage, it uses the original timecode, helping prevent nasty timecode-related issues.

I'm no expect, but I've always thought that video cameras, when in record mode, send the tape through a eraser head (effectively deleteing the vision, audio and additional data such as timecode) before re-recording the new data onto the tape. If this is the case, then stripping/blacking your tape is useless as the timecode you record will be erased anyway!

What are the facts in regards to specifically the Z1P? Should you strip/black your tapes? If so, why? Are there eraser heads in the Z1P? Do they have the ability to "delete" only the vision and audio whilst retaining the pre-recorded timecode?

I'm new to the whole "camera" side of film/tv production and only heard the term stripping/blacking recently. In the past my mini-DV prep has always been: run the tape to the end & back (to "flatten" the tape) and record 30 seconds of colour bars at the start. I always was thought this was the best way to go. Am I wrong? Is stripping/blacking nessessary to help prevent timecode issues?

I look forward to your replies...

Chris!

[Boyd Ostroff]

Welcome to DVinfo Chris! Personally, I don't stripe my Z1 tapes as I don't have a separate deck and don't want to double the hours on my tape heads. Aside from that (in my case) I think it would probably be a "solution in search of a problem." But perhaps someone else can make a compelling case for striping?

[Edward Slonaker]

I've read that it's a "good practice" to black a tape before use simply to lay down the time code for the tape. Nothing more. I can relate to this because I've had a situation (using the FX1) where I've turned the camera off, during filming, and then turned it back on to record something else later in the day. Somehow in doing that, the tape advanced enough to where the camera reset the timecode to "0". It was pure hell trying to get footage captured off that area.

By blacking a tape you establish a single time code for the duration of the tape. All video and audio can be recorded (and re-recorded) without ever losing the original timecode established.

However, I agree with Boyd that, if I didn't already have a separate deck to do this, I wouldn't risk wearing out the heads on my camera; just be a little more careful when turning the camera off and on.

[Dylan Pank]

In my experience, with DV and HDV, striping can also introduce nasty time code related issues.

The way to avoid it is to record additional material at the end of each take, a few seconds. Then if the tape does advance into a blank area, you simply rewind it a second or so and pick up from where you left off.

I don't know who these "Gurus" you speak of are, but they sound like people to me who can't be bothered to keep an eye on their timecode. if you see --:--:--:-- in the view finder, then you just need to back up until you pick up time code.

Originally Posted by chris Hocking

I'm no expert, but I've always thought that video cameras, when in record mode, send the tape through a eraser head (effectively deleteing the vision, audio and additional data such as timecode) before re-recording the new data onto the tape. If this is the case, then stripping/blacking your tape is useless as the timecode you record will be erased anyway!

What you thought is entirely right Chris, so despite seeing yourself as no expert, you appear to know more than these Z1P "gurus".

Just to make something clear. When you've striped the tape, the camera does not re-use the existing timecode, it records new timecode*, and there can be discrepancies between the old and new timecode that cause problems for NLE batch capture that are as bad as timecode gap resets, in some cases worse, as, often being only one or two frames, you'll not pick them up until AFTER you'd done your offline edit. At least timecode gaps are as clear as daylight before you even capture.

This is true of EVERY sub $10,000 dollar DV and HDV camera I've ever used.

*In VT editor language, the camera always records in assemble edit mode, not insert edit mode

[Chris Hocking]

Thanks for your replies...!

Chris!

[Chris Hocking]

From the FCP Manual:

Here are some techniques for avoiding reset timecode counters when shooting with consumer DV camcorders:
- A Prerecord a video signal (preferably black) on each tape before production to create a continuous timecode signal on the entire tape.
This is called blacking a tape. You can do this in any camcorder by pressing Record with the lens cap on and the microphone disconnected (to avoid recording any audio signals). The more professional solution is to use a DV deck and its internal black generator. Some DV decks also allow you to choose what timecode number your tape starts with.

Your thoughts?

[Chris Barcellos]

My two cents:

Unless you are in a heavy production setting and are automating your capture process and absolutely require unbroken time code, striping is a waste of time and equipment. I started out doing it with my DV cameras, trying to avoid time code breaks, but in the end it became a silly excecise not offering any real benefit that I could tell. I do tend not to capture a whole tape for any project, but that would be a reason to want unbroken time code and consider striping if that is inherent in your work flow.

[George Griswold]

I can't stand by any longer. Blacking or striping tapes is for formats like Betacam SP when you black a tape to produce a continuous TC and blacked tape for INSERT edits. DV, DVCAM and DVCPRO erase everything when you record in a camera. Striping really does not do anything, except repack the tape which thankfully is a historical problem, not a current one. The one thing I have found useful is to record 10-15 seconds of black before you turn off the camera and use the method you prefer to back up over the tail of the blank recording. Many NLE's have a check box for ignoring TC breaks.

[Chris Hocking]

Thanks Chris & George for your replies...

Yes as Dylan clearly stated previously and George has further confirmed, STRIPING FOR DV DOES NOT DO ANYTHING.

I'm just wondering why so many people claim that it does (ie. Apple)?

[Paul Doherty]

I guess it still gets recommended for historical reasons despite the fact that as has been clearly stated above it isn't appropriate for DV tape.

As Dylan points out it can lead to minor timecode errors which are difficult or impossible to detect visually, but which are enough to throw an NLE.

Leaving aside the question of extra wear and tear on the camera/deck, it will also waste a fair bit of your own time.

This question crops up regularly and ought to be a sticky on "The Thin Black Line".

[Heath McKnight]

The Z1 doesn't seem to go forward or backwards when turned off and on again, like my old XL1 (forward) or the film school I work at's DVX100a (backwards). You're also putting stress on the tape by striping the whole thing once then recording again, then searching the tape, logging and capturing, etc. Keep it to a minimum by NOT striping the whole thing.

I recommend ALWAYS rolling a minute of color bars, striping the head of the tape. Sometimes, there's flakes of metal at the beginning of the tape from the factory, after it was put in. Which makes for ugly drop outs. And it's a great way to calibrate monitors. If you have tone-capabilities going through the camera, run it to calibrate sound, too.

If you're going to turn off the camera, run 5 seconds of bars--good habit to have, esp. with other cameras.

When there's around 5-7 minutes left on the tape, stripe the tail for around 30 seconds with bars.

heath

[Joe Lawry]

What i we've been taught to do at film school when ever we put a new tape into the 170s or 250s was to go and change the time code setting from regen to preset, then record 30 seconds of bars, and then go and switch back to regen and record everything in that. This method has always worked for me, i never get any drop outs.

You should always record 30 seconds to 1 minute for bars of brand new tapes, as thats where tapes are most likely to have errors - i see it every time when i digitize at school (i actually specilised in post) however i also still get tapes coming in with drop outs, some camera opps never learn.

[Anthony Bristol]

To add to the chorus, don't blackburts your tapes....but remember the END SEARCH button on your camera. WHen in VCR mode if you have been looking back over your footage press it and it will go to the last frame, so when you switch to camera and begin recording the TC runs from the following frame. I have NEVER had a TC break with my Z1.

The other suggestions for recording a little more than you need to and colour bars at the beginning makes very good practice also :)

Good Luck!

[Boyd Ostroff]

Originally Posted by Anthony Bristol

remember the END SEARCH button on your camera.

I've never tried the end search function on my Z1, but on my other Sony cameras (VX-2000, PDX-10) it only works if you're using the same tape and (I think) if the camera hasn't been turned on and off. If you buy the expensive tapes with the chip in them then end search will always work.

Does the Z1 have limitations like this?

[Heath McKnight]

One more thing, if I'm using more than one tape, I go into the timecode settings on the Z1 and change the first set of digits in the T.C. to say 01 for tape 1, 02 for tape 2 and so on.

heath