"Clamped" file has out of range colors!

chewbonkay wrote on 4/12/2002, 10:32 PM
Quick question. I recently rendered a 30 minnute file using the Clamp filter for broadcast colors. When I check the file within the original project using the invert out of range feature, there are no out of range colors once I've selected clamp.

I then added the clamped render to a new project. When I check the new project with the invert colors option, the clamped clip shows out of range colors! Is this real? How can a clip rendered with a broadcast clamp, show out of range colors when simply dropped onto a new track in a new project?

Thanks.

Comments

Ron Lucas wrote on 4/14/2002, 9:05 PM
I just tried this and have the same results as you. After I bring my newly rendered file that had the 'clamp' preset for broadcast colors into a new project, then add broadcast colors and check with the invert setting, many places still show up with the zebra pattern.

No matter what settings I try for the low bound before I render the file, the new project still shows the low bound area always shows out of range.

However on the upper bound setting, if I make the value 1.000 it seems to keep this range legal on my new project.

Ron
winrockpost wrote on 4/16/2002, 9:48 AM
I got the same results,, keeping thread going for an answer from sf
SonyEPM wrote on 4/16/2002, 2:38 PM
Two questions:

Are you seeing the out of range colors in areas of fine detail, (like tree branches, water etc) or are you seeing large blocks?

Have you checked the video on a hardware scope?

Ron Lucas wrote on 4/16/2002, 10:12 PM
I am seeing out of range colors on fine detail. I don't have a hardware scope to do further investigating. I'm just relying on what the broadcast color plugin is telling me when I check the invert button to highlight out of range colors.

Ron
chewbonkay wrote on 4/18/2002, 1:47 PM
Ditto. Ron and I seem to be experiencing the exact same symptoms.
craftech wrote on 4/22/2002, 6:50 PM
So what was the final answer on this?

John
SonyEPM wrote on 4/23/2002, 8:26 AM
After you compress (to DV, MPEG, MJPEG for example) you may see a few pixels in areas of fine detail that are still slightly out of range even after clamping (out of range as reported by the BC filter w/invert). This is mostly due to encoding artifacts, but we are looking into some tweaks to smooth out these errant colors.

PAL and NTSC DV output with clamping checks out on a hardware scope (Videotek TVM-710, others), and you should not have any problems airing these programs. A Sony-certified broadcast engineer (non-employee) has "signed off" on our DV video output being broadcast legal. To my knowledge, no Vegas-generated program has ever been rejected for broadcast. No worries at all for you DVD producers.

If you are creating spots or program masters for national broadcast, please send any evaluation reports from the broadcasters to drdropout@sonicfoundry.com...and of course we'd like to see, and know about, the project!
craftech wrote on 4/23/2002, 9:11 AM
SonicEPM,
Do you think the broadcast colors filter should be used for projects intended for VHS duplication? Thanks.

John
SonyEPM wrote on 4/23/2002, 9:31 AM
To be safe, use the BC filter w/ clamp for your commercial dupe master.
craftech wrote on 4/23/2002, 12:32 PM
Thanks,

John
swarrine wrote on 4/29/2002, 9:11 AM
Where is the invert colors option that shows out of range colors?

I have used the Histogram - Luminance feature to check color safe, but can't seem to find invert colors option (showing out of range colors).

Thanks.
kkolbo wrote on 4/29/2002, 12:36 PM
on the filter setting of the BCC FX dialog. It is not on the preview window.

k
swarrine wrote on 4/29/2002, 3:01 PM
Thanks kkolbo.

It is a preset now, hehe.