#Help needed
9 messages in this thread
Hi there,
I'm new to video editing and could do with a crash course on the technicalities
of timecode, tape formats etc.
I'm involved in producing video tapes for medical teaching. We have a large
collection of VHS masters which have been used to produce crudely edited VHS
copies for students. However, we have recently invested in a desktop video
editing suite consisting of Fast Electronic's Video Machine, S-VHS and Hi-8
source decks and an S-VHS edit deck, and Hi-8 cameras. We need to edit our
master tapes down to VHS (they need to be played on domestic VCRs) from the
Hi-8 and VHS masters (all new source tapes are now recorded onto Hi-8 but much
of the old VHS material is extremely valuable and we will continue to use it).
Many of the VHS master tapes were made up to 10 years ago on an old domestic
quality VHS camera (I don't know the make/model) and have no timecode on them,
as far as I know. My main question is this: In order to get accurate edits
should I make 1st generation copies of these 'source master' tapes with
timecode added and use these as my 'edit masters', even though this will mean
my edited 'master' tapes will be 2nd generation. Also, should I move up from
VHS to S-VHS when copying, and will this in any way minimise the quality loss
during copying.
I would be extremely grateful for any helpful advice anyone can offer me.
Also, some technical overview of the various timecode standards: VITC, control
track etc would be useful.
Thanks in advance.
– Andy
Andy,
It is a very good question, that regarding losing a generation from VHS and
gaining timecode. My guess is that you will want to do this, at least for the
repeatability of time-code, where you can bang out duplicate tapes from an EDL
(Edit Decision List) with little operator intervention. The fact is that you
will lose quality in this step however.
What may be the optimal solution is to bump-up your VHS tapes to SVHS while at
the same time adding VITC (Vertical Interval Time Code). Theoretically the
loss will be "minimal" and you will end up with VITC, SVHS masters, that should
provide the benefit of Time Code for repeatable edits.
-John
John:
>What may be the optimal solution is to bump-up your VHS tapes to SVHS while at
the same time adding VITC (Vertical Interval Time Code). Theoretically the
loss will be "minimal" and you will end up with VITC, SVHS masters, that should
provide the benefit of Time Code for repeatable edits.<
Wouldn't it also be possible to dub the time code onto one of the audio tracks
of the master and use that? Although maybe having a copy for dubs would be
better…
Also, how about bumping up to 3/4"? The problem I've found w/bumping from VHS
to S-VHS is that what you end up w/is a VHS dub on an S-VHS tape (since what
makes S-VHS better is partly that it splits your image into chrominance and
luminance components). 3/4", OTOH, is also a composite system (like VHS), so it
will grab as much info as your VHS tape can output.
Also also <g>, whatever the dub, it should be done w/the aid of a TBC, so that
he loses as little of the signal quality as possible.
Obviously, the ideal solution would be to dub it somehow to a digital format
(or digitize it into the computer) so he doesn't lose *any* quality in
succeeding generations, but I'm not sure that's possible yet–or possible given
what he's got to work with.
Just a few thoughts,
Tim Liebe
Tim,
You raise a number of good points and I guess it depends on his current
equipment and or budget. I don't believe that Fast Video Machine, without the
optional Studio Control Box, will support LTC time code, and depending on what
he has on his linear tracks (track?!) he may or may not be willing to give it
up.
-John
John:
>I don't believe that Fast Video Machine, without the optional Studio Control
Box, will support LTC time code, and depending on what he has on his linear
tracks (track?!) he may or may not be willing to give it up.<
Okay, that's a good point, too (sorry, I wasn't sure).
What about dubbing to 3/4", tho?
Tim
Tim,
I didn't think he had a 3/4" deck so I didn't count it as a possiblity for him.
I think that it would be a solution if he did…
-John
John:
>I didn't think he had a 3/4" deck so I didn't count it as a possiblity for
him. I think that it would be a solution if he did…<
*Ah, so des ka* <g>! (w/apologizes to any Japanese here for my undoubted
misspelling of the term)
I'd still recommend that, if he doesn't yet have a 3/4" deck, he might want to
consider getting one. I know that everyone keeps touting the superiority of
S-VHS and Hi8, but most consumer decks (which I assume his hospital uses)
aren't able to play component tapes, so he'll have to dub it down eventually.
My experience has always been, in cases like that, that 3/4" dubs down better
than S-VHS–even when using a TBC for the dubdown.
Just a thought,
Tim
Even with plain VHS, it's possible to make a Y/C dub, thus preserving as much
signal quality as possible. Both VHS and S-VHS are recorded with separate
luminance and chrominance channels, it's just that the S-VHS luminance channel
has wider luminance bandwidth.
If you take the VHS tape and dub it on S-VHS gear (playback and record decks)
with Y/C cabling, you'll at least avoid the cross-chrominance and
cross-luminance artifacting seen on composite video.
If the editor could accomodate it, adding LTC to the original would be better
yet. One needs to be careful so that a cockpit error doesn't result in erased
video and audio.
Bruce:
>If you take the VHS tape and dub it on S-VHS gear (playback and record decks)
with Y/C cabling, you'll at least avoid the cross-chrominance and
cross-luminance artifacting seen on composite video.<
Really? I didn't realize it was that easy…
Thanks for the tip!
Best,
Tim