AUDIO & VIDEO FORENSICS: STANDARD OPERATING PROCEDURES

Videotape Clarification
Many videotapes are submitted to Primeau Productions forensics examination. More often than not, the quality of these tapes is less than optimal. Causes for poor video quality may include:

• Dirty video recording heads
• Worn video recording heads
• Recycled/reused videotape stock
• Misaligned video recording heads (which produce inconsistent picture quality)
• Low lighting
• No lighting
• Images out of focus
• Operator error.

Essentially, video clarification is the process used to address these less-than-ideal video conditions – to produce a sharpened, enhanced video product.

Our Adobe Premiere video program uses a process that allows us to break a video down into its components and enhance picture quality and sound. The components are adjusted then realigned, resulting in a clearer, crisper image. Once the video has been downloaded into the computer, we can then adjust gamma color tints and intensity, ratio of black to white to grey tones, contrast and phase, plus sound-quality attributes.

Note that no video clarification steps used by Primeau Productions will cause damage to the original recordings; maintaining the integrity of an original videotape is, of course, of paramount importance.

However, working with the original master recording always produces superior results. The master tape is much higher quality than a copy – or a copy of a copy, and so on; in point of fact, the original is the highest-quality available. Our clarification process will be measurably more successful if we have access to the original tape.

It is far more difficult to enhance and clarify a copy. In copies, much of the quality is lost in the transfer process. The copy is fuzzier than the original; each generation of copy adds more “noise” to the subsequent copy, decreasing clarity and quality.

Although the copy is showing the same image, the information contained on the tape will never be as sharp as the original. When you examine a copy closely, you find that the image will often be too low in quality to enhance and identify. As few as five re-records of a videotape can cause enough degradation to prevent identification of the desired image.

To save on materials costs security and surveillance systems often use the same tapes over and over. However, if it becomes necessary to submit the footage for forensic examination the forensic expert may require twice as much time to enhance the quality (and, therefore, the ‘usability’) of the footage. The cost of using fresh, new videotape is considerably lower than the expense in time and labor involved in attempting to clarify and authenticate tapes that have been used and re-used.

If you are recording a video that may require forensic examination, it’s in your best interest to use new tape stock for the recording.

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	Forensics Services – Audio and video services
	Forensics: Audio clarification services