Fastforward VHS tapes?

When our family first got a VCR (over 15 yrs ago) I was told that you should always fastforward a new, ie blank, tape through to the end and back “to stretch the tape”, and that just whacking the tape fresh out of its wrapper and hitting record was somehow bad.

Is this true? Does giving a blank VHS tape a little stretch before you start recording with it have any benefit? If it doesn’t now, did it ever?

Or is it just a load of bollocks?

The only thing FF’ing a tape will do is re-spool the film onto the rollers at a rate that your VCR sets, not the factory. This might save you from having a tape that is too tight(you know the ones your VCR thinks have reached the end and rewind your tape all the way?).

-Sam

Well, it goes to show that there are just some things that even GaWd does not know.

I have it from a very reliable source, my brother’s sister’s mother’s husband’s son, that you do indeed need to Fast Forward a tape before you use it for the first time.

See, first you have to understand how a VCR tape works.

Everytime you play a tape with a VCR it stores the data on the tape in local memory then it removes the data stored on the tape and then it cleans the section of tape and then replaces the data back on the tape (this keeps the information fresh so that you keep the quality of the image over time, you know how dusty those tapes get).

However, if you have a blank tape, it has no data to store, so the VCR does not really know what to do, fast forwarding it is kind of like formating it much like you do with a floppy or hard drive when it is new. The fast forwarding process knows that there is no data so it writes blank data to the blank tape and gets it ready to record data on the tape. Not fast forwarding it could cause you to be writing new data on top of the old blank data instead of the new blank data, this could cause poor image quality and so the cleaning of the image in the future will not be as effective.

So, remember to always fast forward your new tapes to format them properly and to occasionally fast forward your exisiting tapes just to keep them clean and minty fresh.

Glad to be able to clear up the confusion.

Jeffery

777: I will not absolutely, positively swear to it, but I strongly suspect that your brother’s sister’s mother’s husband’s son is nuts.

What I think you’re describing (badly) is what’s known in the TV biz as “blacking” a tape. It is done to imprint “time code” on the otherwise virgin tape stock.

Time code is like a sequential series of reference points that a tape deck can read; it is a string of placeholders that contains no image or other “information.” To use a film analogy, virgin videotape is like a strip of blank celluloid with no sprocket holes or frames; a blacked tape (w/TC) is like a film strip with sprocket holes and defined frames, but the images inside the frames are still blank.

Now, IF what your brother’s sister’s mother’s husband’s son is saying is that you must black the tape before you record on it, there are two problems in his logic: 1. VHS tapes are not blacked because they have no time code (only broadcast format tapes like Betacam need to be blacked), and 2. tapes are blacked at real time speed, not fast foward speed (thus a 60 min. tape takes 60 mins. to black).

I will also add that the arrangement you describe whereby a tape is read, stored, erased, and rerecorded sounds highly dubious to me, and in all my years in the TV biz I’ve never heard of such a thing. I would argue that given how video images degenerate after multiple generations of duping, such a process would result in an unviewable image after about a half dozen plays.

But hey, maybe you know something I don’t…

Don’t you guys think that if such a thing was necessary the manufacturers would say so on the box. Wouldn’t there be a notice that said “For Best Results, Fast Forward Tape Before Use”. Think about it. Wouldn’t they want you to get the best quality??

My YooHoo drink says “Shake Well Before Opening”
My Towels say “Wash Before Use”

Why would the tape company be holding out on everybody?? I think the formatting idea is crap.

The neighbor of my mother’s cousin’s half-nephew’s hair-dresser says your brother’s sister’s mother’s husband’s son is off his rocker if he told you that.

Fast-forwarding does absolutely nothing to the encoding on the tape, so even if the “no initial data” hypothesis was true, fast-forwarding wouldn’t do anything to help.

Secondly, unlike your floppy or hard drive, the signal encoded on the tape is an analog signal, not a digital signal. Your disk drive needs to align any future data it writes to the disk with the data currently on it; formatting the disk places specific markers on it so that the drive can do so.

On the other hand, your VCR, since it encodes an analog signal, has no such restrictions. If you start recording over a partial frame-in-progress of the current contents, as soon as your TV gets the vsync token from your new recording, it can realign itself.

Now, in defense of your brother, the previous data almost always leaves a small trace of itself behind embedded in the new content, which can create minor visual artifacts. I believe that there’s even enough of a trace left that someone, with the right equipment, could approximately reconstruct the previous signal, at a very low-quality. But recording a blank signal on a tape prior to recording some new content should get rid of most of that ghosting. The initial data on the tape is white noise, so some ghosting from that versus a pre-blanked tape might have been what he showed you.

As far as the statement that playing a tape erases data that is then re-recorded as it passes by, I believe it to be at strong difference with reality. A magnetic field strong enough to alter the tape would prevent the VCR from reading the original signal on the tape. When you record on a VCR, there are two recording heads – the first one erases (mostly) the previous data, and the second one puts down the new signal. But the only thing that I’ve ever heard of that does destructive reads is the sense amplifier of a DRAM buffer.

ok. i shoot and edit video for a living.

yes, FFing a tape and then rewinding it before use is of great benefit.

there are probably a few reasons for it. i only know one.

you see, the tape wasn’t just made 10 minutes ago. it has been sitting on a shelf, been transported, banged, etc.

by FFing and REWing it, you are tightening up the slack that occured in the tape from sitting around and being jostled.

[/quote]
Don’t you guys think that if such a thing was necessary the manufacturers would say so on the box. Wouldn’t there be a notice that said “For Best Results, Fast Forward Tape Before Use”.

[quote]

they do. i use DVCAM and betacam at work. maybe the manufacturers don’t care about you mere consumers. : )

but it is still a good idea.

that nonsense with the formatting is ridiculous.

damn. i hate screwing up the quoting.

As far as recording the tape, it really makes no difference. But… bear with me for a moment:

I have a very plain VCR with a very plain tape counter which is what most of you have. To know how muchtape I have left I set the counter to zero as I start the tape. As I record or play the tape advances at a constant rate but the counter does not because it is coupled to the spool.

I can make a table telling me the correcspondence between counter reading and time elapsed. But my next step was to find a mathematical formula that would link these two variables. This was not difficult.

But… once you have done this, you realize you do not need to set the counter to zero at the beginning of the tape. Just by measuring the speed of advance of the counter you can know time elapsed and therefore time remaining. You can insert a tape that is in the middle (unrewinded) and by measuring the speed of advance of the counter know exactly where you are on the tape.

But, this is unique to every tape, it is not universal. To do this you need to establish these parameters:

  • Duration of tape (say 120 minutes)
  • max reading of counter at end of tape if started at zero (or what is the same, reading at end of tape minus reading at beginning of tape, say 7450)
  • ratio of speeds at beginning and end of tape (say 3.27)
    (these numbers are actual numbers I have used on my VCR)

having determined those parameters for a tape, I can measure the counter speed and know exactly where I am on the tape without need to set the counter to zero at the beginning of the tape.

I do this by hand on my VCR BUT I have seen higher end models that will do this automatically. To do this you have to tell them the tape model or let the VCR figure out the parameters by itself which can only be done by a full rewind.

So there you go. Everybody’s right.

well, not you.

it does make a difference, as i mentioned in my earlier post.

>> it does make a difference, as i mentioned in my earlier post.

Sure it does. I am trying to remember the last time I heard someone say “Man, I messed up trying to record that show because I forgot to rewind the tape and it totally screwed up the recording”.

Well, I don’t know if it’s of great benefit at home, but it’s a necessity for offline editing.
Well, maybe not a necessity, but it sure helps. Basically, there is something called “pre-roll” when using an offline video-editing suite. You set your marks on each tape (In-Points and Out-Points), then the suite rolls back to between 3 and 10 seconds before the In-Points (when the recording starts). To quote the reason from Ascher & Pincus’s The Filmmaker’s Handbook page 407, “This preroll is needed to get the machines up to speed before the edit occurs.” So you can’t just throw a tape in and start editing. Usually when I’m editing I black a tape first, so I don’t have to worry about that.
However, this is to get the machines synced and running at the right speed to each other. This is the obvious reason for doing this for editing, but I don’t see why you “need” to do this for recording off of a TV. If you don’t, you’ll get a couple of seconds (if that) of static at the beginning. If you do fast forward and rewind, you might get rid of the static, but it’s not like you’re saving your VCR a lot of wear and tear. It took the same, if not more, energy to get FF & Rewind the tape as it would to start it. With cameras which are higher quality, and since you are then most-likely going to edit it, this would be beneficial. Unless you’re editing and you need the tape ready for the speed of the editing suite’s VCR, I really don’t see the purpose.

Sorry, I should have clarified the preroll. The reason you can’t just throw a tape in and record is because if it can’t roll back, you can’t record. When you black a tape (giving it a steady signal), you then FF into the tape so you can have the preroll.

I dare say that no expert could tell you whether a recordings been done on a tape that’s been FF/RW vs. one that hasn’t. Even you, Kilgore Trout. Do a little test for yourself. Make two recordings of the same thing. Then have someone else play each one and see if you can tell the difference. There is no way you’ll detect a difference.

Sometimes they get a little slack. Remember those little thumbsize things that you could put in the reel takeup to tighten it? Yep. No necessary anymore. Modern vcrs & modern cassettes very well made.,

i guarantee that i couldn’t.

not until the picture drops out or there is a glitch in the tape.

go ask any person in the television or video industry what the first thing they do when they black a tape is.

…and i probably couldn’t see the difference between 7.4 IRE and 7.5 IRE NTSC black, either.

but it matters.

i just called the national video tape co. in seattle, washington and asked them the benefits of fast forwarding and rewinding.

they say that by doing this, you retension the tape and remove debris resulting in fewer video dropouts.

dropouts are quite noticeable. even to you, bill h.

http://www.natlvideo.qpg.com

All very enlightening.

Kilgore’s explanation is along the lines of what I was told. And FFing/RWing is a useful way to remove debris from a tape, as I’ve discovered over the years.

Wow!

What’d I say?

I guess GaWd DOES know a thing or two…

-Sam