Buying Videotape (page 2)
Receiving and Retaining
The technical terms for a tape's ability to record and hold signals are coercivity and retentivity. Coercivity is defined as any magnet's ability to be "coerced" into receiving an electrical charge (such as a video signal), measured in Oersteds (Oe). Retentivity, on the other hand, is any magnet's ability to retain a charge over time, measured in Gauss. These are perhaps the most important technical statistics regarding videotape quality, but unfortunately, they're usually not statistics that the manufacturers are willing to provide. The one thing you can usually be sure of is that a certain manufacturer's higher grade tape will have greater coercivity and retentivity than its lower grades.
In Conclusion
Several factors - price, tape format, brand name, casing type, and whether to buy bulk or not - may play into your blank videotape purchasing decisions. In general, higher-quality videotapes will not give you higher-quality pictures. However, as a result of more solid construction, they may last longer.
3 Rules of Thumb
Three of the most important things for consumers to consider when purchasing videotape are:
- Buy only name-brand tape from reputable vendors.
- Buy the best grade of tape you can afford; the benefits are usually worth the extra cost.
- For best results and long-lasting videos, buy shorter tape lengths; 60 minutes or less is a good rule of thumb.
How a Signal Gets Recorded to Tape
The simplest way to record a signal to tape is to apply a magnetic charge to it as it passes over a stationary record head. This is how most audio tape recorders function.
Videotape, on the other hand, utilizes the helical scanning technique. Inside a camcorder or VCR, you'll find a circular drum that's positioned at an odd angle relative to the tape; that's the record head. It rotates at precisely 30 revolutions per second, corresponding to video's 30 frames per second. As the tape moves past the record head, it usually records a single frame of video for each angular (helical) pass. 8mm tapes reserve a tiny portion of the end of each helical scan for recording audio and time code, whereas VHS formats generally utilize a simple linear audio track or two for audio. VHS-family hi-fi stereo audio is the exception to this rule. In VHS hi-fi systems, the audio track is actually embedded within the video signal. In the case of digital tape formats, the record head spins much faster, and each pass records a discrete block of data rather than a single frame.
Is Bulk Tape Worth it?
In the pages of our magazine, in mail-order catalogs and on commercial Web sites, you'll often find ads for large quantities of blank tape offered at substantial discounts. To discover whether it's a good idea for videographers to purchase this bulk tape, we spoke with John Waring, a professional videographer and tape duplication specialist. John specializes in creating tape duplications for local school districts, and he uses bulk VHS videotape for the majority of his distribution projects.
"The thing about bulk tape," Waring said, "is you have to use it for what it's intended for, which is large-scale distribution. Say you're a wedding videographer, and the client wants 200 copies of the ceremony to give to family and friends. Bulk tape is a great way to go. It'll hold up pretty well over time, especially when you consider that people probably won't play it very often over the long haul.
"Shooting and editing, however, is a whole different ball of wax. You should always, always use professional grade videotape for shooting and editing professional jobs, period."
