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-   -   How to color correct using vectorscopes and waveform monitors??? (https://www.dvinfo.net/forum/adobe-creative-suite/119053-how-color-correct-using-vectorscopes-waveform-monitors.html)

Jose Milan April 10th, 2008 12:03 PM

How to color correct using vectorscopes and waveform monitors???
 
2 Attachment(s)
Hello,

I recently got a dsclabs Frontbox chart to color correct both, single camera recording and multi-cam projects.

I've search the dsclabs website and many webs about waveform and vectorscope monitors I kind of get the idea of knowing what the do (at surface levels). In the places I've search the tell you what they do one is for color correcting and the other for luminance levels, but not how to use this tools with real examples of recordings or what to look in using the chart from dsclabs. I live in Pal world, and dsclabs is made for NTSC but people here in Spain are using them with great results despite being made for a different system.

I would like to know how to use the clips of the Frontbox chart and how to color correct with the help of the monitors, everyone says is very easy but I dont get it, I need to know what premiere color filters I need to use (fast color corrector, rgb balance, gamma corrector...????) to get the colors where they belong, and "know" how to look at the monitors at the same time and keep applying the controls in the filters.

I've enclosed to screens to see what I mean, the vectorscope seems to show that colors are almost there, but the colors in the chart dont seem to natural to me.

Tripp Woelfel April 10th, 2008 03:04 PM

Unless you know something about the technical aspect of color correction and the scopes I'd recommend getting a good book. I tried searching the Web for info and really didn't find anything valuable.

I bought "Color Correction For Digital Video" by Hullfish and Fowler and found it very helpful. Read most of the way through it then worked on a short project. I felt reasonably sure that I was on the right track after that. Good reference to go back and check things later too.

It's on Amazon.

Perrone Ford April 10th, 2008 03:33 PM

Well first thing, it would help if you shot the "chart" and not the chart, the hands, the arms, etc. That would get some of that noise off the chart.

Second, does Premiere Pro generate color bars? If so, place about 5 seconds worth of color bars on your timeline and see what that looks like on your vectorscope. Notice where the dots fall. White should be DEAD center, and each primary color should fall into it's box.

Once you see that, bring up a filter that will let you alter hue and saturation. Play with the saturation of the color bar clip to see how the colors move in relation on the Vectorscope. You should seem them all contract and expand equally toward black/white and away from black/white.

Next, slowly change the hue and watch the colors move around the vectorscope. This should show you what happens if your white balance is off toward the warm, or the cool, or even the green side.

The Vectorscope is ALL about colors. The Waveform monitor is about luma, or light intensity. For the purposes of computer video, you would LIKE to keep your values between the 0 line and the 100-105 line. In NTSC, you want to keep your intensity between the 100 line and the 7.5 line which is just above the 0 line, and off to the right usually.

You will see this in perfect color bars as to how black, white, and the shades of different intensity fall. When shooting your own video, you are looking to make sure you don't exceed the extremes, and that you have a nice spread of tonality between the two extremes.

You make changes in the shape of the waveform monitor with the brightness and contrast filter. Brightness will move the entire waveform up or down depending on how you adjust it. Contrast will expand or contract the waveform so keep it between the extremes.


Now this is a very rudimentary introduction, but it's basically how things work. The DSC charts do a number of things. They cane be used to check camera alignment (for cameras that can be adjusted) they can tell you about how your camera is responding to lighting, and if you shoot the chart right before you shoot your subject and make no changes to the lighting, it will tell you when you get to post how to make things look as they should. The same adjustments you make to get the chart correct in the vectorscope are the same ones needed to get accurate color of your subject under the same lighting conditions.

Make sense?

Jose Milan April 11th, 2008 05:31 AM

Quote:

Originally Posted by Perrone Ford (Post 857879)
Well first thing, it would help if you shot the "chart" and not the chart, the hands, the arms, etc. That would get some of that noise off the chart.

Okay should only record the chart and only the chart.

Quote:

Second, does Premiere Pro generate color bars? If so, place about 5 seconds worth of color bars on your timeline and see what that looks like on your vectorscope. Notice where the dots fall. White should be DEAD center, and each primary color should fall into it's box.
Yes premiere can generate color bars, but also the cameras...should I use the ones genereted in the camera? Is it better? what do I win?. But anyway, to get it clear: first I should do the color bars and check and then I should start checking the staff for the chart, right?

Quote:

Once you see that, bring up a filter that will let you alter hue and saturation. Play with the saturation of the color bar clip to see how the colors move in relation on the Vectorscope. You should seem them all contract and expand equally toward black/white and away from black/white.
Okay.

Quote:

Next, slowly change the hue and watch the colors move around the vectorscope. This should show you what happens if your white balance is off toward the warm, or the cool, or even the green side.
Okay

Quote:

The Vectorscope is ALL about colors. The Waveform monitor is about luma, or light intensity. For the purposes of computer video, you would LIKE to keep your values between the 0 line and the 100-105 line. In NTSC, you want to keep your intensity between the 100 line and the 7.5 line which is just above the 0 line, and off to the right usually.
This is for NTSC, what should change for PAL? do you know? This is for television purposes, mainly our stuff is for viewing in web, should I change those settings you suggested? I know that correcting for tv will get me better results anyway even tought we do it for web I think (sometimes we do stuff for tv too).

Quote:

You will see this in perfect color bars as to how black, white, and the shades of different intensity fall. When shooting your own video, you are looking to make sure you don't exceed the extremes, and that you have a nice spread of tonality between the two extremes.

You make changes in the shape of the waveform monitor with the brightness and contrast filter. Brightness will move the entire waveform up or down depending on how you adjust it. Contrast will expand or contract the waveform so keep it between the extremes.
Okay

Quote:

Now this is a very rudimentary introduction, but it's basically how things work. The DSC charts do a number of things. They cane be used to check camera alignment (for cameras that can be adjusted) they can tell you about how your camera is responding to lighting, and if you shoot the chart right before you shoot your subject and make no changes to the lighting, it will tell you when you get to post how to make things look as they should. The same adjustments you make to get the chart correct in the vectorscope are the same ones needed to get accurate color of your subject under the same lighting conditions.

Make sense?
Perrone this makes so much sense now, very well explained. Thank you very much...now I know much better. As you can see I still have some questions, like the ones above, plus some more:

1. Since I got the chart to make recording with different cameras look as close as possible, I should record some frames with the cameras, maybe record some seconds of color bars generated in each camera (better than in premiere, or should I use both: camera and premiere) and then for each camera do the whole process, that is make the chart look like it should, and then for the other cameras do the same, the process to make the chart look good for this camera again, and this should make the cameras look similar by itself, right???

Again Perrone, thank you for explaining so well, I'm getting there, I need I little more help and as suggested read some book to get deeper, but with this and a little more answering I can trully make a lot of things already.


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