DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Canon GL Series DV Camcorders (https://www.dvinfo.net/forum/canon-gl-series-dv-camcorders/)
-   -   Line at top of picture (https://www.dvinfo.net/forum/canon-gl-series-dv-camcorders/11423-line-top-picture.html)

David Deehan June 29th, 2003 03:19 PM

Line at top of picture
Hi everyone,

I have just completed my first wedding shoot. In post I applied a slow motion effect to a number of clips. On playback, at the top of all slow motion scenes, there was a flicker along the top. I therefore examined the clips in more detail. On close inspection I noticed a thin black line and a faint coloured line below that on all captured scenes. The colour of the faint line varied depending on the colour directly below it. I then examined many shots going right back to when the camera was bought. All exhibited the same lines along the top. When a clipís velocity was slowed the re-sampling method used by VV4 introduced the flicker. This flicker does not occur on clips captured from an old Sony DV cam, using exactly the same hardware and software.

I realise that this is only visible on computer and not on television since there is no overscan on a monitor, but I often demonstrate my video on laptop.

I have posted examples of above at http://homepage.ntlworld.com/david.d...r/flicker.html

Additionally and to go over old ground again, I need some more advice on the Colour Bleed problem.
In my previous post (see http://www.dvinfo.net/conf/showthrea...t=colour+bleed )
Jeff Donald recommended the use of an 85B filter. This I got, but sadly it had no effect on the bleed problem.
I have recently updated my web page with more examples of this problem (
http://homepage.ntlworld.com/david.d...XM2/index.html ). Maybe Iím expecting too much from the XM2.

Thanks in advance


Chris Fangio June 29th, 2003 04:25 PM

Hi David,

I also see this line when capturing via Premiere. I don't know if this is normal and if this also occurs when shooting in normal mode as I was using frame mode.


Jesper Hallen June 29th, 2003 04:28 PM

maybe it's the top ending of the picture you mean? it must have an end somewhere i believe. =)

Chris Fangio July 1st, 2003 07:22 AM

Are we the only ones with this line on top of the picture?

Rob Lohman July 11th, 2003 11:45 AM

I have a similar thing on the bottom with my XL1s. Do you guys
have a GL1 or 2? You might want to add a very small black bar
on the top before rendering out your final version. You won't
see it on a TV due to underscanning and on your laptop it will
look "natural/ok" because we are used to see black surrounding
movies etc.

David Deehan July 12th, 2003 05:45 PM


My camera is an XM2. The problem is not restricted to a single black line along the top, but also a faint coloured line below that. Have you checked out my website (see address in previous post) where there are some examples.


Rob Lohman July 14th, 2003 03:56 AM

I did check it out. But since I own an XL1s and not a GL/XM2 I
don't know if this is "normal" for your camera. I was hoping
someone else would respond to confirm or deny this....

Sorry I can't be of any more help to you.

David Deehan July 15th, 2003 08:49 AM


Iíve just discovered this thread from last year, which describes your problem with the XL1S in detail, namely a black bar along the bottom and a bright bar above that. (http://www.dvinfo.net/conf/showthread.php?s=&threadid=1743&highlight=black+line). This was certainly a very lively thread.

With my XM2 the problem is reversed Ė a black bar at the top of the picture with a coloured bar/bars below that. I am hoping those with an XM2 (or GL2) exhibiting the same will provide some feedback. Have many others also experienced this or is it a QC problem? Could this be a generic defect in XM2ís as it is with the XL1S (my little Sony TRV 25E does not exhibit this)? Have Canon only moved the symptom from the bottom of the picture to the top? Is it only evident on 3CCD cameras? Would I be right in saying that Canon semi-pro cameras are restricted to 720x574 (PAL) pixels or less (the coloured line can be stretch up to 3 pixels)? Having to crop all video is not an acceptable resolution.


Chris Fangio July 15th, 2003 11:55 AM


as I mentioned before I also do have this problem with my XM2. So it would really be nice to hear from other people if they have this problem. I tried capturing via Scealyzer and Premiere and the problems keeps the same.

Did you use interlaced or frame mode?


David Deehan July 15th, 2003 03:35 PM


I have looked at some clips shot in normal and frame mode. Both modes show lines at the top.
Are you just getting the "black line" or "black and coloured lines" as described above?


Graham Bernard July 15th, 2003 10:40 PM

Called to the Bar!
David, where does this become a problem for you? If it is a problem for you, then I'd be very interested for my own piece of mind, to know where I should start concerning myself? For example, does this bar stuff appear in Pan/Crop in V4? Can you see this happen in frame size reduction? Is the bar visible in frame manipulation in general? Hmmm...


Chris Fangio July 15th, 2003 11:26 PM


my footage looks exactly like yours (at least the bars are the same). I will post some framegrabs this afternoon (it's 07:25 am here in Germany right now).

Grazie: As mentioned before the lines are visible right aber capturing no matter which software is used. At least this is my theory.

Graham Bernard July 16th, 2003 12:35 AM

. . . yes, I understood that, but do they or can they be seen in any V4 manipulation? Or are you only asking if there is an issue with having, as you go onto editing?


David Deehan August 1st, 2003 02:07 PM

Hi everyone,

Apologies for plugging on about this problem, but I have just downloaded a clip mentioned in the following recent thread http://www.dvinfo.net/conf/showthread.php?s=&threadid=12679 . This uncompressed clip shows exactly the same black and coloured lines at the top of picture, which I experience. It is an extremely large clip (140MB), so to download a broadband connection is advisory. For those who have downloaded it, could they stop the clip at the 6 second mark and inspect the top few lines. I have in the past downloaded other clips but these were all GL2(NTSC), not XM2(Pal). The GL2 clips do not seem to exhibit this phenomenon.

By the way, if Jonathan Richards reads this post, I hope you donít mind me making reference to your video file.


Bud Kuenzli August 1st, 2003 07:56 PM

my gl2 is free of such lines
in the fwiw category, my gl2 is indeed free of such lines.

All times are GMT -6. The time now is 05:34 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2021 The Digital Video Information Network