View Full Version : Fluctuating Line at top of HDV image


Aren Haun
June 18th, 2006, 09:01 AM
Hi All,

I appreciate some advice: I'm using FCP 5.1.1 to capture from a SONY HC1 camera and it's working fine, no problems, except one. The top of the image, after I capture, fluctuates. By this I mean that the top border of the image, in the timeline (or the browser, or on Quicktime), shakes. It looks fine on the camera and when I'm capturing, but afterword it has this aberration.

I've tried changing all my settings on the camera and in Final Cut, but nothing has helped. I suppose it could be on the tape, but this is several tapes that I've captured with the same problem. I've also scanned all these threads on this site and haven't found anyone with exactly the same symptom.

Any ideas?

- Aren

Boyd Ostroff
June 18th, 2006, 03:14 PM
Welcome to DVinfo Aren. I've never seen anything here about that problem either. But I'm just wondering.... the HC1 has electronic image stabilization which uses extra pixels that are outside of the image area. Could the fluctuation be caused by that?

Were you shooting handheld or on a locked down tripod? Was image stabilization (steadyshot) turned on?

Cole McDonald
June 18th, 2006, 08:34 PM
I've done some work with deinterlacing tricks and have seen something like this (may not be the same abberation). When switching from odd to even fields in my 60i > 60p experiments I get a flickering line at the top. Is this footage being deinterlaced in anyway? This may be something to look at.

Aren Haun
June 18th, 2006, 09:10 PM
The de-interlacing image filter worked. I'm not sure whether or not I've had image stabilization turned on or not, I'll double check that.

Thanks for the help.

- Aren

Aren Haun
June 18th, 2006, 09:52 PM
By the way, is my image quality going to be deteriorated by using the de-interlacing filter? Anyone?

Thanks again for the advice. This is a great site.

- Aren

Boyd Ostroff
June 19th, 2006, 06:51 AM
Depends on exactly what you did... the basic deinterlacing filter in FCP simply discards every other scan line and doubles the others, so yes, you would be losing 50% of your vertical resolution in that case. I'm guessing that the reason the flickering line disappeared is because you've thrown it away!

As a practical matter, this problem is probably a non-issue because consumer TV's won't show the image all the way to the edge anyway...

Laurence Kingston
June 19th, 2006, 08:34 AM
You could just mask the top line by overlaying a black line at the top.

Aren Haun
June 19th, 2006, 08:44 AM
I think you are right, I'm losing the line because I'm losing 50% of my image. I've tried putting a black line over it, which is what I'll probably do if I don't solve the issue - I just didn't want there to be an extra line, but more importantly, I wanted to know what the problem was. I've also tried blowing up the image to 101%, and that works, too, but again the question of quality loss.

I think the problem is something to do with the interlacing on the camera, but I'll probably end up just covering over it.

Anyway, thank you all for your help.

Boyd Ostroff
June 19th, 2006, 10:54 AM
Aren, it seems like you've stumbled upon something interesting, and even though you are using FCP I suspect it has more to do with the HC1 than the software. So I'm moving this thread to the HC1 forum; let's see if other HC1 owners have noticed this problem.

Heath McKnight
July 9th, 2006, 09:15 PM
I saw that flicker at the top when I captured footage using Apple's Apple Intermediate Codec, but not when I captured native HDV in Final Cut Pro 5. Not sure why that happened. Did you use the AIC in FCP 5, Final Cut Express HD or iMovie HD?

heath

Aren Haun
July 11th, 2006, 10:41 AM
I'm using Final Cut 5.1.1. And I'm not using Apple's Intermediate Codec. But I'll make double sure that I'm not.

I still haven't found a solution to this problem...

For now I plan to just cover the line with a black bar.

Thanks for all the replies.

Mikko Lopponen
July 11th, 2006, 02:09 PM
I'm seeing exactly the same line. It's probably an hc1 thing as I'm editing the mpeg2 stream natively.