Why black edging on video?

[Tom Matthies]

What kind of camera was the video shot with in the field? Many cameras, especially analog cameras like BetacamSP, will have the black edges along the sides of the frame. These are not mistakes but are usually just the “blanking” of the camera. Most cameras have a blanking adjustment that will purposely bring in the edges of the video. It’s a throwback to the analog, linear editing days. Blanking can also get added depending on how the video was captured. Some capture cards, again, especially ones that capture analog signals can add this blanking while capturing the video. As they say, “It’s not a bug, it’s a feature!”
Depending on your setup this isn’t unusual to see.
How to get rid of it? A slight blow up of the video? Depending on how and where the video is being shown, it might now even show on a screen or a TV monitor. You usually only notice it while playing on a computer in a window on the desktop.
Tom

[Ian Smith]

Thank you for the response and helpful information. I had never heard of “blanking” before. Is that the actual technical term for that?
– I’m using a GL1
In this case, the final footage will be placed in a DVD, and it’s unknown where all it will be seen. The most important of all is it’s soon to come debute, in which it will be shown in front of a very large crowd, so naturally I want it to look as good as it’s content, and with some shots filling the entirety of the frame, and many with the “blanking”, I don’t want this glitchy effect. I’m not actually certain on what they will do the presentation on, though I asume a large projector screen, or a very large screen television. But then copies of the DVD will be sent out too. So, unfortunately I’ve got all the venues to cover.

Is it something I just have to deal with in the exporting process, and crop… or can I change a setting on the camera OR capture process? I’ve not known this camera for long, and as far as capturing I’ve looked over the settings pretty well, but there’s always room for error.

Thank you very much for your help!

[William J. meyer]

ibsmith,

This has been plaguing me also. One of my frustrations was not being able to correctly identify the source of the issue. Besides appearing in footage shot in-house, I would also see it in many high-end productions delivered to us as well in fantastic demo reels on the web (when it appeared in a collection of 20th Century Fox trailers I was even more perplexed).

Many of the deliverables at work tend to be web-only or computer-only, and we’ve had to do essentially the same as you (generally I’ve done the cropping in Compressor). My past attempts to discover the nature of this beast proved futile. But Tom provided me with the correct vocabulary! It made all the difference. From what I have just read and experimented with in FCP, blanking, in our case, is a function of our capture codec, DVCPRO50. Here’s a link to a Panasonic pdf document about the codec.

As Tom mentioned, they even refer to it as a “feature.” But as I understand from this Wikipedia entry, blanking is a hold-over from the early days of television.

So maybe if you change your capture codec the blanking will not be there. When I switched to 8-bit uncompressed, for example, it was gone.

ciao!
-wjm

[Ian Smith]

Wow, that’s very helpful information. I don’t feel out of the norm by going about my cropping solution now.

Thank you very much for this information, very useful!

[Paul Dickin]

Hi
Do a Google search for 702 pixels, and you will find a ton of stuff about CCIR-601. now ITU-R BT.60…
The problem with a ‘Standard’ is that it is immutable, and hasn’t been changed for today’s situation.

Here’s a quote:
“Full NTSC is actually 486 lines (@29.97frames/sec) but since the DCT algorithms used in the DV codec use a block size divisible by 8 or 16, the frame is cropped to 480. The NTSC active line period actually represents about 710 of the 720 total samples. An analogue source or many digital camcorders blank the outer 10 samples. This active period and the original 486 lines represent the 4:3 full image. If we crop 6 vertical lines to make 480 then we ought to crop 8 horiz samples to leave 702.
It happens that in PAL, the equivalent active period is also 702 samples (even though no lines are cropped) so it is a curious coincidence.
So to repeat, the active 4:3 picture for NTSC occupies 702×480, and for PAL 702×576.”

[Alan Lacey]

Same thing happened to me years ago when I bought a couple of JVC cameras. The Digi-S (can’t remember the model number) was full D1 and gave a ‘complete’ 720×576 picture (I’m Pal here).

Then I purchased a JVC DV700 (I was lead to believe it had the same chipset so would match up nicely) but this recorded with analogue blanking (it’s 704×576) to JVCs ProDV. JVC in the UK never did understand my gripe.

Alan

[Tom Matthies]

I too have a JVC DV-700 camera and see the same blanking problems as well. Just the design of the camera, I guess.
In the old days, horizontal blanking was fully adjustable by tweaking the “pots” inside the camera. These days, most of these adjustments are done by software tweaks that are often not accessible by the user. Ah, progress!
FWIW.
Tom

[Alan Lacey]

Nice camera otherwise though Tom. Mines still giving good service. V nice colorimetry.

Alan

[Tom Matthies]

Yep. I use it weekly. I’ve hung a Firestore FS3 on the back and record mostly to disk these days. Really speeds up the editing process. Just copy to the raid and start editing. It’s a great time saver when I shoot in DV. Always record to tape for backup as well..
I’m also still using a tried and true BetaSP camcorder as well.
Just got a nice new Sony XDCam HD at work though. Might see myself getting spoiled soon.
Tom

[Alan Lacey]

We obviously think alike Tom, I bought a PDW350 last year – love it but don’t have much call for the HD bit of it yet. Doesn’t the FS3 on your DV700 make it a bit unwieldy? I was temped some time ago but chickened out with all the FS horror stories.

Alan