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Color Correction! Is there a basic foundation?
I cant for the life of me figure out weather I should do "Color Corrector" Contrast and Brightness, HSL, Secondary Color adjustment....Curves...etc first and then apply the next FX, etc..
Is there a "basic foundation" and chain sequence I should be following when correcting my colors. Any good tutorials out there....(preferably one that exlpains the eye dropper tools) Thanks |
This is something I've struggled a lot with also. I haven't really found any good single resource, but there are many things out there that give you little bits of information. I've come to the conclusion that I will have to just buy a book or video on the subject, I just haven't decided which one yet.
VASST have this one: Absolute Training for Vegas+DVD, Vol. 4: Color Correction, Enhancement and Image Restoration It is co-hosted by Glenn Chan, who definitely knows his colour and Vegas. I will likely spring for it sometime. If you find anything particularly useful, let me know. Otherwise, the only thing I've really found helped was picking a tool, and playing with a known entity, like the SMPTE colour bars, or a solid colour, and watch what happens to a pure colour. Then apply it to an actual video and look for the colour you were playing with, and watch what happens. Get in the habit of looking for the presence/absence of detail in shadows and highlights, find something white and see if you can detect a cast on it, etc. Practise I think is the only one, as it's so very subjective. |
I would try to stay away from Contrast and Brightness as much as possible since it raises ot lowers all exposure and color thru out the clip.
I generally start with the 3 way corrector since you can not only change the color but also control the gamma and gain. Then I goto either the 2ndy CC to finish it off then Curves to adjust the highs and lows. As Craig said CC is kind of subjective and a lot depends on the monitor you're correcting on. How it's set can make a hugh difference. I use HSL to heighten the overall color, punch it up, or I use the NewBlue Essentials. Glenn Chan has some really good tutorials about color correction as does Edward Troxel in his newletters. I would start with the 3 way first and go from there. BTW, it was great talking to you yesterday. Stay dry! ;-) |
basic foundation is to 1st match all the shots in a given scene or sequence so they look similar... typical CC on an individual shot might use Levels, Curves or Color Corrector (my usual 1st choice).
Color Corrector (1CC) 1) normally i adjust Offset first to get the shadows looking right. 2) adjust the gain to get highlights the way i want 3) move gamma to locate the appropriate midpoint. 4) repeat steps 1-3 til happy. 5) adjust saturation to get desired amount of color (sometimes do this during 1-3) 1CC Eye Dropper a) click the + or - (plus is selected color (adjustment), minus is opposite color (complementary)) b) move cursor to target, left-click, draw mouse over area; it'll sample the colors covered and average a result c) adjust the Magnitude (0.000 to 1.000) to vary the amount of saturation (ditto Angle to vary color) d) double-click target to return to centre (neutral) After 1CC u may want to use 2CC to adjust elements within the shot... things like skin (especially skin), grass, sky, street signs... these are sorta non-negotiable; if they don't look right, everyone can tell and everyone notices; they need to look fairly believable no matter what style you're going for... sometimes its easier to do 2CC after 1CC, sometimes before... either way is fine. Secondary Color Corrector (2CC) anyway, 2cc allows u to mask an area by hue, saturation or luma so it's pretty easy to get specific items isolated, then tweak with the parameters in the top half of the filter. 2CC Eye Dropper a) click Selected effect range eyedropper b) drag mouse over area u wish to adjust c) check the "show mask" box and turn on/off each of the 3 limiters: luminance, saturation, hue d1) luma is often good to start with; get the Low/High approx set, then sweep Smooth to desired amount d2) saturation depends on circumstance; but use the same as luma d3) hue; drop Width/Smooth to less than 1.0, sweep the Center to find the sweet spot, expand the width the minimum needed, then open the Smooth up. d4) u may want to turn off each limiter as u step thru, then turn all on and tweak, or repeat d1-d3 e) now use the adjustments in the top half; i find Saturation, Chrominance (angle/magnitude), and Rotate hue, work with the least side effects... Gamma, Gain, Offset become noticeable more quickly. --- beyond this u should probably go to Glenn Chan's site and read his Sony Vegas Color Correction Tutorial (also check out other articles he's written there) Sony Vegas Color Correction Tutorial --- then consider buying Absolute Training for Vegas: Color Correction, Enhancement and Image Restoration Absolute Training for Vegas+DVD, Vol. 4: Color Correction, Enhancement and Image Restoration --- more? look for books by Steve Hullfish on Color Correcting for Video. |
Thanks for the info so far...you guys once again have armed me with lots of information. Im trying to sift through Ed Troxels news letters too... Anyone know which one pertaing specifically to Color Correction?
I THINK where I am getting confused is coming from the still photography world whe I shot in RAW format, I had a histrogram to help me do color correction. Im not big in color correction as my fashion photographer mentor was very anal about getting the image right.....Right out of the camera.. but when i needed to color correct i went by the histrogram, one eye dropper tool for white, the other for black, and one for gray midtones... Hmmmm perhaps i should throw my digital calibration target in my gear bag and shoot a few frames of this to help eh? (calibration target has a black, white, and gray stripe) I have been through my Class on Demand DVD....but they just touched the tip of the iceberg on color correction... Perhaps ill spring for the Vasst DVD. Don... you need me to send my Toro down? We are getting hammered up here! |
Hey David, yeah we're gettin' hit hard as well. Big one tonite and tomorrow. Thanks but my Craftsman will do the job and if not, I'm not going anywhere anyway so I'll just wait for it to melt. ;-)
Rob did a super job explaining the various pieces of Vegas CC, if you've got the time I would just play around with it and try all the various functions to see how they affect the clips. Beauty of Vegas, can't hurt anything. Save each different version under a different name. Then you can bring all the clips onto the timeline and compare. Way back when in the olden days, you know back when we shot real film in still cameras, ;-) I had an opportunity to work some with Victor Skrebneski, man what a artistic minds eye and a very well versed technician. Of course he also had 1 or 2 assistants to keep the camera runnin', but I learned a bunch, mostly how to light and shoot portraits and model composites with 1 light and make it something that had a life of it's own. Ahh brings back the memories. |
In a word.....
The Art and Technique of Digital Color Correction by Steve Hullfish... Absolutely fantastic!!!! |
David, one of the stickies in the newsletter forum is an index telling you what is in each individual issue. Just look there and you can easily find the issue you need.
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You might also find the chart at:
http://www.dvinfo.net/forum/what-hap...n-summary.html of help (use the one attached to my post of 9 September 2008). Good Luck, Richard |
Might I suggest that instead of reading quick charts you study Chapter 8 (Color-Correction) of Digital Compositing for Film and Video, by Steve Wright.
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Rather an impertinent comment, don't you think?
The chart is intended as no more than an aide-memoire or a quick introduction to the whole question of colour correction and I should have thought it went without saying that you need to educate yourself further by trial and error, by looking at instructional videos or by reading books on the subject. Richard |
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The book I recommended, on the other hand, is exactly pertinent to this thread because it offers exactly what was asked for, a basic foundation for color correction. |
In the RGB world 255 represents extreme white (fully opaque) and 0 extreme black. (fully transparent). That is an RGB of 0,0,0 will produce white and of 255,255,255 will represent black. These are the measures used by Vegas in identifying colours in, for example, its Sony Text Generator or in its histogram.
Richard |
Richard, the 256 values (steps) you're referring to are levels of luminance, not hue.
0-0-0 to 1-1-1 is one step, 1-1-1- to 2-2-2 is another step, all the way to 255-255-255. On the other hand, colour (not hue) has 16,777,216 values/steps (256 x 256 x 256). 0-0-0 to 0-0-1 is one step, 0-0-1 to 0-0-2 is another step, all the way to 255-255-255. That still doesn't sound right to me but I can't think of a better way to say it. http://en.wikipedia.org/wiki/RGB_color_model says and shows it much better than I can. |
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Here is the hue adjusting effect from Sony Vegas. It treats hue as a floating point value between 0.00 and 1.00. That seemingly only offers 101 values, but you can type in a more precise value (e.g. 0.123456).
Hue is actually an angle on the color wheel. It determines what color a pixel has regardless of its luminosity or saturation. That is, its value, while numeric, represents things such as red, green, orange, etc. |
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I was taught that an RGB value of 0-0-0 is pure black while 255-255-255 is pure white. |
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I think I'm trying to say something similar in that the RGB figures represent the colour values of R,G and B with the mix between them and the differing values leading to different colours or, if used within only a single R, G or B field, the intensity (value) of that colour. Hence the 16,777,216 steps you both refer to but Adam is right in that the hue itself is identified from its angle on the colour wheel.
To go back to the start of the debate, the chart (which has attracted a number of favourable comments from experienced colourists who have said that they wished they might have had a similar aide memoire when they were starting to explore what is a huge subject in its own right) was designed to give brief introductory guidance and to help the beginner take the step to the next level. It was never intended, nor could it ever be, a comprehensive or infallible guide to the subject as a whole Richard |
you guys are speaking different language here right now. Someday I hope to learn what your talking about...
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David, the DVD referred to in this thread is $60 and both books are less than $30 each.
All of them are very worthwhile investments in helping you to better understand what can be a very confusing topic. I have the DVD and have watched it several times. |
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If you look at the Sony Vegas vectorscope and move the cursor over it, a yellow line connects your cursor position with the center of the vectorscope (see the enclosed image, though unfortunately it does not show the cursor itself, but in this case I held the cursor at the point where the two withe lines connect). In the upper right corner, an angle is shown. In the enclosed example, the angle is 240°. That is the hue of any color that would lie anywhere on the yellow line seen in the example. As you can see, the yellow line crosses the letter G, which stands for green. So, the hue of any green pixel, from dark green to light green is 240°. When used in effects, such as the "add hue" example above, Sony Vegas expresses this angle in values from 0.00 to 1.00. If you multiply that value by 360, you will convert it to degrees (Vegas, and many other editors, uses the values from 0 to 1 instead of 0 to 360 because it is more intuitive, especially for people who are not aware of hue being the angle on the color wheel). So, if you "add" 0.5 hue, Vegas will rotate the hue of every pixel by 0.5 * 360° = 180° (or, if you prefer, it turns the entire color wheel by 180°). That is a particularly interesting effect as all colors look like the "negative" but without the change in luminosity that exists in a true film negative. In an actual negative, light green turns into dark magenta. In the rotation by 180° light green turns into light magenta instead, as neither its luminosity (brightness, from dark to light) nor its saturation (color vs. black and white) is affected. In other words, the color of each pixel becomes its complementary color. If you add 1.00 instead, Vegas will rotate the wheel by 1.00 * 360° = 360°, which means nothing will change (since turning a wheel by 360° just brings it back to its original position). I hope this explains it. If not, keep asking. ;) |
Excellent explanation Adam.
For more help, here's a newsletter from Sony on Using the Vegas Pro color scopes |
Thanks, Mike. And thanks for the newsletter link.
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Adam... Do you think my comprehension of this topic is somewhat limited due to the fire water I used to drink when i lived in Harshaw? LOL
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Next time you come up to see the Hodag, stop by and we can go over it. :)
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The Vegas Pro 8 Companion DVD set by Gary Kleiner covers it. I think in the DVD titled "Image enhancement". I contacted Gary to see if he is going to come out with a DVD set for Pro 10 and he said yes. I will definitely get it. A lot of good tutorials out there but I particuarly like his because it is 12 DVD's so much more comprehensive than most. This DVD set and the VASST ones I own have been a lifesaver when we get stuck and can't figure something out.
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Re: Color Correction for 5D footage
So we have been so used to colour correcting our Z7 & GH1 footage and now that we have moved to 5D and a new TV, everything looks orange.
How can I reduce the orange most effectively? I use colour correct, levels + colour curves as base settings in process. I have just tried to reduce the mid tones as an experiment towards the blues...I have no idea if that's right or not. All advice would be appreciated. |
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