Re: why does my waveform say my blacks are below 0 IRE after I change the levels??/ by Jeff Brown on May 8, 2008 at 2:24:43 pm
Ah-- the built-in software WFM. Does it read less than zero if you turn off the checkbox for the "chroma" display? And if so, maybe you could post a screen shot.
I've adjusted the levels, taken off the levels filter, and still having a weird reading of less than 0IRE after I render out....during the tweaking of the levels i can set it to where i need it to be but once rendered it goes wonky.
the only way I can get rid of this problem is to Check the box at the top of the waveform monitor that says "setup (7.5 IRE) in premiere pro cs3....but i don't really get what this has to do with anything
Re: why does my waveform say my blacks are below 0 IRE after I change the levels??/ by tyler smith on May 9, 2008 at 9:25:41 am
here's a frame grab pic from my cell phone....the line directly below the double line represents 0 IRE.....
keep in mind I used the three-way color corrector to set the levels....i've used the "levels effect" but it automatically tells me that my levels are between 0 and 100 when I don't even adjust the settings....which is really strange....
Re: why does my waveform say my blacks are below 0 IRE after I change the levels??/ by Jeff Brown on May 9, 2008 at 2:23:00 pm
A screen grab would be clearer: Shift+Ctrl+PrtScrn (usually near the 'break' key), but----
I don't see anything truly below zero, except the heavy line on the right; that presumably includes the sync pulse, which had better go to about -20 IRE or your signal is out of whack.
Re: why does my waveform say my blacks are below 0 IRE after I change the levels??/ by tyler smith on May 9, 2008 at 3:05:54 pm
i thought the green line on the right side of the waveform was represented peaks of blacks and whites....i was using this to balance the black and white peaks.
am i balancing my levels completely wrong? Should i also be stretching the blacks and whites as close to the 0 and 100 IRE level as closely as possible?
Re: why does my waveform say my blacks are below 0 IRE after I change the levels??/ by Jeff Brown on May 9, 2008 at 6:30:09 pm
[tyler smith]"i thought the green line on the right side of the waveform was represented peaks of blacks and whites"
Hoo boy, do i feel stoopid. You're right. I'm used to hardware 'scopes; so I made a wrong assumption. But in the image of your overall waveform, I don't really see anything below zero. Obviously, Premiere sees something there, and I'm not sure what.
[tyler smith]"Should i also be stretching the blacks and whites as close to the 0 and 100 IRE level as closely as possible?"
In my opinion --and take it for what it's worth-- see above ;>), you should not be stretching the levels "blindly". Scopes are good to make sure the technical aspects of the video are correct, but for visual decisions, you really need a calibrated monitor to judge the image. Use 'scopes to check your decisions, but trust your eyes too.
Re: why does my waveform say my blacks are below 0 IRE after I change the levels??/ by tyler smith on May 9, 2008 at 7:44:31 pm
Thanks for all the help Jeff...I played around a bit with it and you're absolutely right. I set the whites and blacks as close to 0 and 100 as possible, that is if those levels are relatively close to the 0 & 100 values. I'm careful not to over do it to a point that ruins the image quality. If stretching & tweaking the levels improves the overall quality while keeping the technical aspects in check, then it's a bonus. After that I might tweak the gamma in order to match it better with the preceeding & following cut, this really makes the flow of images so smoother...but it seems that the image is easily distorted and gamma is almost better to be used sparingly.
I Think I have a pretty good grasp on things now, and now only need to learn about color grading. :)
