Why your magnetic video tapes have a short life.

By now, everyone knows that the shelf life of a videotape is about fifteen years and this only if the tape has been handled and stored correctly and played...only occasionally.

In 1996, I received my certification as a VCR Technician, in doing so I learned many interesting things about how analog signals work and how they are stored on tape and read back by the amazing VCR.

There are many factors working against the longevity of your videotapes. Most Internet based video conversion businesses will tell you all about the magnetic binder on the tape and how environmental conditions and usage will eventually wear away the magnetic signal deteriorating the tape until it is useless. If you want a further explanation of this click HERE.

There's another equally, if not more pressing, reason to convert your video to DVD now. this has to do with the control track on the video tape. The control track is recorded linearly on the edge of the tape.

To understand why this is important, you need to have a basic understanding how the video signal is recorded on the tape. Video signals use a great bandwidth of frequency to hold all the necessary information. This equates to a lot of information that must be stored on a videotape and read back by a VCR. In order to accomplish this, the video is recorded in a helical scanning method (see fig 1.) The signal is recorded at an angle. If a VCR were to record the information needed in a linear fashion, you would need a tape the size of most living rooms to hold a movie and it would have to be pulled past the video head at a lightning speed. So, in order to accomplish what seemed to be impossible, the video signal is placed at an angle, thereby allowing much more information to be held on less tape. The video drum has two heads on opposite sides of each other and rotates at a high speed in the opposite direction that the tape is moving. When one head reads from the bottom to the top of one line of information the second head is just beginning to read the next line. Together this creates on full frequency signal and is repeated over ad over again. Neat huh?

HERES AN ENLIGHTENTING FACT:

No VCR in existence has ever used more than two video heads at one time. There are some VCR's that have two sets of video heads, each 180 degrees apart with each set having a matching gap in the actual head (get's real technical) but the 'second' set of heads are only used for slow motion playback and never used with the first set. They have a different head gap width that allows the picture to be played back slower without too many artifacts in the picture. The companies that made seem that the more video heads you have the better the picture were deceiving you. Sure some brands of VCR heads are better than others but quantity doesn't matter here. Some companies actually consider the stationary erase head, tracking head and audio head as "heads" to sell the machine for more money! Ever hear of a seven head VCR? There you go. Four on the drum and the other three I just mentioned. Every VCR has a stationary erase head, tracking head and audio head.

Getting back to the control track. As you can now imagine, the timing of the heads to the video signal has to be absolutely precise. This is where the control track comes in. It delivers a steady pulse that is read by the VCR to keep the drums in sync with the video signal on the tape. Were talking precision here. Ever have to adjust the "tracking" on the VCR because the picture wasn't coming in good? What you were doing was electronically slowing or speeding the drum to match the video signal on the tape. This is something you'll do more and more of as the tape gets older.

Now, here's the main point. If your tape gets stretched at all the control track gets damaged and the heads cannot properly sync to the video tracks. At best, you'll get what's called "tearing" of the video picture. That's when the top or bottom of the picture looks warped. This is a time base error that effects the video head to signal synch and can affect the middle of the tape as well. Depending on how bad the control track is you may lose the ability to play any video at all!

Now, here's the kicker! VHS-C tapes, you know, those cute little compact tapes that get put into the motorized adapter to fit in any VCR were so poorly designed that every time you put them in that adapter YOU STRETCH THE TAPE. For this reason, alone, VHS-C tapes do not last very long. You ruin your tape every time you put it into the adapter. So, even if you decide not to go with converting your VHS-C tapes do yourself a favor and NEVER use the adapter. Always run it from the camera itself - don't worry, you wont break your camera any faster but your tapes will last a little longer.

Another way the tapes get stretched and ruined is by cheap machines that do not slow the tape down before bringing it to a stop when rewinding or fast-forwarding. These machines rely on a clear leader (see-through part of tape) at the beginning and end of the video. An infrared light is always shining across the video path into the tape and when the clear leader appears the light gets read by a pickup on the other side and stops the machines spindles cold. This stretches the tape! Even most stand-alone tape rewinders (that were supposedly made to spare your VCR from extra wear and tear, more misinformation) work the same way! Even worse, some spin faster! I've fixed many tapes that had stopped so abruptly that the clear leader actually pulled away from the inside reel of the cassette or worse, the tape itself snapped! can you imagine how that damages the control track?

I use professional equipment to capture analog video - specifically, a Canopus ADVC300. This device has professional features that correct some time base errors via a hardware linear time base corrector. It has the ability to enhance poor video, correct white peak and black expansion (balance) and increase color saturation and hue. It separates the luminance and chrominance and allows for 3D noise reduction for an overall clearer picture. My system has the ability to adjust a weak washed out picture, bringing back dull video via the hardware capture settings.

A lot of other "video capture cards" or "converters" are what's commonly referred to as "garbage in, garbage out." Sure, they may be able to capture clean, undamaged video without dropping frames, but they will do nothing to save a slightly damaged or aged videotape. The ADVC300 is highly regarded among video professionals and is an expensive part of a system that costs thousands of dollars to yield the results I expect. This year the ADVC300 was voted as the best hardware video product of the year by BYTE.COM (Mar '04) - Congratulations Canopus!

I no longer repair VCR's I now specialize in analog to digital conversion with or without editing, DVD authoring and also digital to analog recording for those people who have refused to give in and buy a DVD player.

I currently limit my work to the NTSC Standard. Mini DV, standard VHS and VHS-C tapes only. Inquire about other formats.

If you are thinking about video conversion to DVD, please consider Metabol-Video, you won't be sorry, I guarantee it.

Don't let others fool you - even DVD's do not last forever as some sites say. They, too, are susceptible to high heat, warping, scratches and extended periods of bright sunlight, but are far more durable than your vanishing magnetic video. DVD's are easily duplicated and have no generation loss. It is for this reason that I will not put copy protection on your finished product unless you specifically ask for it.