A/B editing, B-roll, etc.

megabit wrote on 5/5/2008, 1:50 AM

Guys,

I'm relatively new to "pro" video editing (Vegas 7 was my first Pro level tool), so the whole concept of the A/B layers, B-roll etc - while intuitively obvious - is something I have no hands-on experience with. I'd do with some practical explanation of its uses. Some links, perhaps? TIA

Piotr

PS. I have a feeling I actually did do something like A/B editing by simply using several video tracks, and switching between them using the Mute envelopes. How does Expanding Track Layers, and using A/B, differ from that in practical terms?

Comments

PeterWright wrote on 5/5/2008, 2:15 AM

Vegas does A/B editing on what seems to be a single track - as you've already mentioned, Expanding Track Layers shows what's "really" happening - two tracks with a transition track between them - that's how it used to be, but most prefer the single track/transition by overlap approach, which is much better on space.

B Roll is another term - often used for "supporting footage" - shots you get to cover interruptions or omissions in the flow of the "main" video, or to break things up and make it more interesting.

No doubt others will add other uses for these terms ...

megabit wrote on 5/5/2008, 3:26 AM

OK - so after adding several clips (events) to a track, and later Expanding Its Layers, I end up with them alternating on the A and B layers, and with the transition track between them.

Is that ALL there is to it? What if I really have an A-roll and B-roll, and would like to intercut the A with the B pieces here and there: how do I place them on my timeline? As I said, before digging into the Expanded Track Layers, I simply put them on separate tracks and used the Mute envelope...

My questions:

1. How do I place the A-roll and B-roll material on the timeline, in order to be able to use the A/B editing (is the alternating method the only one)?

2. After inseritng a transition effect between adjacent clips (alternated between A and B layers), and then collapsing the layers - I can see the second clip is not synchronized (pink), which is understandable. However, using the right-click menu's Synchronize option produces weird results. How is it supposed to work?

winrockpost wrote on 5/5/2008, 6:13 AM

Thank goodness we dont have to use the ole linear a/b editing. Meg , not sure what you are trying to do but sounds like you are doing a multicam edit and vegas has a pretty good feature for that, as do some third party guys.
good luck

megabit wrote on 5/5/2008, 6:22 AM

While indeed I am preparing fro my first multi-cam edit, this is not the case now. I am just trying to acquire a more insight knowledge of Vegas, that's all ;)

BTW, I know the A/B editing is sort of a past thing, but frankly learned about it first from the Edius forum (and NOT from the DSE's book on Vegas I bought recently). This inspired me to check it in Vegas - hence my questions. Purely academic; but still I'd like to know the philosophy.

As I said: after putting all my clips on a single track and expanding its layers, I can see how the clips can be alternating between A and B, and transitions applied between them, etc.

However, assuming I have the A-roll and some B-roll, what is (or used to be) the way of A/B editing using them? How would I arrange them on Vegas timeline to try and use this approach?

farss wrote on 5/5/2008, 6:28 AM

"Is that ALL there is to it?"

YES!

Overall you're confusing two terms.

A/B Roll editing with "B Roll footage" They are totally different things.

If you were cutting real film with a work print you'd cut your A roll shots using A/B rolls, you'd do the same with your B Roll footage.
Typically the second unit crew shoots the B roll footage, the stuff that doesn't matter so much. That footage doesn't go onto the B roll in a A/B Roll edit, no sir.

If you're trying to intercut second unit footage then it's more like a multicam edit if anything however that's a bad analogy as drama isn't chronologically accurate.

The A/B roll paradigm (sorry) probably came over into NLEs from the film world where you had to have two rolls. Scene 1 goes into roll A and there was a matching length of black stock on the B roll. Scene 2 this reversed. If you wanted a dissolve the two had to overlap the cut by the length of the dissolve and you'd mark the dissolve with a chinagraph pencil as a long "X". You only got to see the dissolve after you got the answer print and every dissolve cost money.

So in summary, forget using A/B Roll editing, it gains you nothing apart from confusion. I started out doing it in Ppro because before that (decades ago) I had cut 16mm. Once I made the transition (a slow dissolve :) ) I never want to go back to working that way.

Bob.

farss wrote on 5/5/2008, 6:31 AM

"However, assuming I have the A-roll and some B-roll,"

See my post below. You CANNOT have some B-roll. You must have as much B-roll as A-roll strictly speaking.

busterkeaton wrote on 5/5/2008, 6:38 AM

I would suggest you're not going to get much value out of this academic exercise.

I would suggest, using DSE's book and learning the Vegas way of working by doing a sample project in Vegas. I think you'll find it's more intuitive for a new editor and a quicker way to work.

Are there any Vegas editors out there who still find A/B editing useful?

Grazie wrote on 5/5/2008, 6:43 AM

Bob - Yes.

Buster - No. I have tried and just can't do it.

Actually I found the whole "adding" a clip to an A/B session the A/B tracks change places - very off-putting.

Grazie

winrockpost wrote on 5/5/2008, 6:43 AM

http://www.videomaker.com/article/3650/

this is an old 1999 article that has nothing to do with vegas but may be of interest

megabit wrote on 5/5/2008, 6:56 AM

OK guys, got it now. Thanks - I'll stick to the way of doing things I adopted intuitively since my first days with Vegas.

rmack350 wrote on 5/5/2008, 8:08 AM

The main value of expanding track layers (to me) is to demonstrate that Vegas is doing A/B editing automatically, and also to show that it's totally unnecessary to know it's happening.

It's a good way to demonstrate what's happening behind the scenes.

Rob Mack

baysidebas wrote on 5/5/2008, 8:24 AM

Actually, expanding the layers is helpful in seeing exactly what your edits are, particularly when there is a lot of short cuts of similarly looking material. When all of these are on a single track [collapsed layers] it's often very difficult to keep track of what's what.

rmack350 wrote on 5/5/2008, 8:57 AM

Very true. I was forgetting that. It's very easy to see a 1 frame long snip of footage this way.

Rob

xberk wrote on 5/5/2008, 10:41 PM

My recollection on film editing was that A/B and sometimes C rolls were used in the negative cut to make an answer print (or married print). Scenes alternated between the rolls with black leader filling the spaces so the A/B/C rolls were always identical in length. Even a straight cut between scenes had to have A/B rolls to look seamless on film. You could not physically splice two pieces of film together and expect a print to look clean. An A/B roll dissolve overlapped and was kind of a cheap optical effect as really it was a fade out and fade in on opposite rolls.

Camera original was used in a negative cut to conform to the final cut of workprint. Neg cuts were done by specialists -- film editors rarely cut their own negatives. When editing workprint I never used A/B rolls. I never used more than one roll of workprint. Some moviola flatbeds I used could handle multiple sound tracks, but only one image. You marked the workprint to show a dissolve. TItles over could not be shown without an optical being done to one piece of film.

A and B cutting in video editing is just a carried over term to indicate using two alternating tracks of image and all the kind of effects that you can do (dissolves, superimpose etc) when two tracks are used. It certainly appealed to us old guys who didn't imagine that overlapping scenes on a single track (as in Vegas) would make a nice dissolve.