black line on video

asafb wrote on 7/16/2002, 4:44 PM
hello

i have a sony pd150 camera..when set to auto exposure the video capture video preview looks fine; when i switch it to manual exposure, all of a sudden an extremely thin line colored black apperas on the video! When played back on a tv, i see absolutely no difference - i do NOT see the black line on my tv when going preview on external monitor -- this did not happen before -- what the heck is this!?!?

Comments

asafb wrote on 7/16/2002, 4:45 PM
the line appears on the top (the first line)
Chienworks wrote on 7/16/2002, 4:58 PM
Most likely the reason you don't see it on your TV is because of the "safe areas" issue. The television display cuts off some of the outer edge of the image.
asafb wrote on 7/16/2002, 5:09 PM
should i be concerned with this - is my cam defective?
asafb wrote on 7/17/2002, 2:08 PM
<html>

<head>
<meta http-equiv="Content-Language" content="en-us">
<meta name="GENERATOR" content="Microsoft FrontPage 5.0">
<meta name="ProgId" content="FrontPage.Editor.Document">
<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
<title>New Page 1</title>
</head>

<body>

Okay, here is this black line I'm talking about. SF - what is this? It's only
when i go to manual exposure on my PD150 Sony DVCAM.</p>


<img border="0" src="file:///D:/Documents%20and%20Settings/Asaf%20Blasberg/My%20Documents/blackline.gif" width="516" height="401"></p>

</body>

</html>

asafb wrote on 7/17/2002, 2:09 PM
woops,i guess it doesn't support html ---

anyways here is the picture:

go to

http://fortissimostudios.com/blackline.gif

thanks, asafb
SonyDennis wrote on 7/17/2002, 5:29 PM
Well, that's in Draft resolution, so I can't really tell what it is. Put it in Best quality and "Display at Project size" (rt-clk in video window). It will be a bigger picture, and we'll be able to see if there is a black scanline up there.

Even if there is, I wouldn't be too concerned, it's never going to be seen, it's in the overscan area. Many older camera put multiple-pixel-wide black bars on the sides.

///d@
Tyler.Durden wrote on 7/17/2002, 7:02 PM
I suspect it is the way the cam was designed.

Ocassionally digital video processing delays the signal significantly enough to utilize correction in the picture area.

Manufacturers have used the technique of masking portions of the image to cover partial lines and other artifacts that processing delays throw in.

This might be moot in the total digital era, but if this only happens when you flip a switch, it might be applicable.

Frequently, the masking is not in the active picture area (rather, in the blanking), or if it *is* in the active picture area, it may be at black-level to meet specs. And as stated, it is so far outside the safe area, that the manufacturer is willing to rationalize its presence. That notion may be of little consolation if you are projecting the footage or encoding for the web (since you do), 'cause those presentations display edge-to-edge.

You may want to make a similar mask to keep the top edge of all the video consistent.


HTH, MPH

asafb wrote on 7/18/2002, 12:08 PM
Well my concern is on the computer screen after mpeg2-ing it, it still shows, so my dvd, if played back on a computer monitor, WILL display that stupid black line... :(

A shutter speed of 1/30th of a second is important for me because it diminishes the video look a little bit.
Tyler.Durden wrote on 7/18/2002, 12:17 PM
Well...

If you can't beat 'em, letterbox 'em?

Since yer reducing the video look, a bit of letterbox will mask the line and give you a more film-like aspect.

Just a thought.

Regards, MPH
asafb wrote on 7/18/2002, 12:49 PM
yes i guess i could letterbox it, but what will it look like on 16:9 tv's
Tyler.Durden wrote on 7/18/2002, 1:01 PM
"what will it look like on 16:9 tv's"

Just more letterbox, I think. (if you just use masks to letterbox)

Cheers, MPH