Yes, but not noticeable until the 6th or 7th generation …
The video signal degrades slightly every time it passes in or out of a device that processes the signal. Generation loss can be avoided by making an exact copy of the digital video file recorded on the tape. The dub, or “file transfer” will have no “generational loss”. – Similar to copying a file on your personal computer.

Processing Video… The Digital Betacam VCR processes video using the following parameters; color sampling at a rate of 4:2:2, a maximum data rate of 90 Mbps, 10 bits per sample, and a compression ratio of 2:1.

Compression of the video signal, by its very nature creates some loss of information. The compression software (algorithm) is tasked with evaluating the video frames for similarities. As similarities are identified, the video data can be recorded for the first frame with a flag to re-use the data for the next video frames. When a change in the picture content is detected, the process starts over.

Loss of Picture Information… For instance, if our picture has a blue sky that “basically” doesn’t change for 30 frames, we can record the blue sky data for frame 1 and re-use the data when playing back frames 2 to 30. This provides a significant reduction in the amount of data to record on the tape.

If our original blue sky contains slight differences in color, we may lose some of the blue shading during the compression process. Satisfying the compression ratio may require compromising on the picture detail. This is why video processed at a high compression ratio tends to lack detail.

The DigiBeta format has been successful because it has a low compression ratio and is very efficient in recording and playing back the video signal.

File Transfer… At the beginning of the article I mentioned it was possible to avoid generational loss if you could make an exact copy of the digital file recorded on the tape. On the rear of some of the current generation professional VCR’s there is a BNC connector labeled “SDTI” – Serial Data Transport Interface. The SDTI connector “allows for lossless transfer of data to other devices which have the same codec”. Since this is a “file transfer”, the video can also be dubbed faster than real time.

For additional information take a look at the following links…
Compression in Digital VTRs – http://pro.jvc.com/pro/d9/ARTICLES/WATKINSON.htm
What is SDTI? – http://www.digitalpostproduction.com/Htm/Tutorials/WhatIsSDTI.htm

Watch for more about video engineering with Chris here on DavidRyanMediaSolutions.com

Chris Vazquez can be contacted at chris.designsmith@verizon.net or 301.953.1427