[MacDV] Re: forcing iMovie to display the dialog

[Gregg Gorrie]

on 2/21/08 8:07 PM, Mike Rehbein at rotorwash at mac.com wrote:

> Either storage media can be used to store the DV file.
> There is no difference in compression, saving a DV file to tape or a
> hard drive saves the same video quality.
> 
> The topic is then simply, which media is going to give best service
> over time, and ease of use.
> 
> The tape can be referenced any way you wish but you will need to
> manually move the tape to the location and begin reading and stop
> reading, again, manually.
> 
> Moving tape across the heads is a wear and head contamination issue
> over time.
> 
> Tape is not as robust a storage media as is a hard drive.
> 
> Tape wears with each use, much more so than a hard drive does but that
> won't be a factor if you don't use the tape much.
> 
> When a spot on the tape becomes unreadable, there goes the file.
> Tape is not stored inside a nice clean environment as the disk of a
> drive is.
> 
> Think of It an external storage media, subject to changes in heat,
> moisture, contamination.
> 
> Mike

I would have to disagree with you on these points.

Firstly, I believe the original poster was talking about outputting the
final video sequence to DV tape. This is not a file - it is linear digital
video. You can access and capture any part of it (albeit much slower than a
hard drive) a number of ways. The easiest would be to do a batch capture in
something like Final Cut Pro or Premiere, where you can simply input the
time codes of the clips you want (TC is on the DV tape) and they will
automatically shuttle the DV machine to the appropriate points to capture.
Alternatively, you can manually shuttle to the desired points and capture
them in iMovie or other programs that don't deal with time code.

While tape has it's issues (degradation over time), for long term archival
storage it is far superior to a hard drive. All it takes to lose a file on a
hard drive is to have a head crash (slight bumps at the wrong time), have
the directory or a file corrupted, or sometimes the drive just stop
spinning. I have a box full of dead drives that have bitten the dust over
the years, and with most of them there were no early warning signs. Hence
the absolute requirement to always have a complete backup.

Let's say you had a single 12 GB file that held the complete contents of a
one hour DV tape. One flaw in that data file and everything is gone. If you
get a dropout or two on the DV tape, the media before and after it is still
good and you can still salvage the rest of it.

Ultimately no matter what format you choose, it's wise to have a regular
backup strategy and also have a plan to move your archives to new forms of
media as they come into play. At least with digital stuff, you're not losing
quality as you do this.

For what it's worth, my suggestion would be to keep the stuff on DV tape,
get a Blu-Ray burner and make two copies of everything that is important
enough to back up, keeping one copy at a separate physical location. Save
the hard drives for shorter term works in progress.


Gregg