I am curious why all flim have to be darken, but not to TV programs? What filters or color corrections have need added? When do they do that (before the editing or the final thing to do)?

The reason they color correct the way they do is because when you're making a film, that's just part of the process. Otherwise it would look like crap. TV stations don't usually shoot on film. They shoot on tape, and they usually don't color correct that much because they're at very tight deadlines.

When you edit film, usually you edit offline for a while, which means you edit with lower quality footage. When you put it online, you color correct and do all that stuff.

It's kind of difficult to explain. I hope this answer is sufficient.

Thanks for the information. Its very helpful.

However, I'd like to know still, if it is a good practice to do the color correction if I want to create a video clip with a normal consumer DV, where the videos are being shot on tape. What color corrections are needed? Are there a standard or a set of rules?

I understand its difficult to explain, and sometimes even there are no reason to explain. Just another curious question. You said the color correction is applied at the final stage, why dont the TV stations place the correction in their realtime boardcast systems? I know most of most of them can do real-time transitions while boardcasting them, and I don't think a color correction in between is a heavy load work to those systems.

Tommy

Hi Tommy:
Yes, in general, I think it's very important to make adjustments to video also. However, the latitude of video (or the degree to which you can make adjustments) is not nearly as great as film so it's especially important to get the video looking right while shooting.

In analog, you could adjust the black level, the luminance, the chrominance, and the phase of the chrominance. In the digital realm, there are basic equivalents to that, plus many more options. I would suggest adjusting the "levels" and possibly the hue/sat on every clip of video that is in the edit.

HTH, Cheers,

^^

I personally hate doing audio. I go in with a fresh face and hella' vigor, but just loathe it so much, since all I have to do audio with is Garageband and FCE...

i color correct everything. theres always ONE small tweek that needs to be made in terms of color correction.

Tommy, what do you mean darken?

On film, if post production is done in high definition, Grading as it is know, is completed after all work on changing the film (online, compositing, special effects) are completly finished. The film, usually in HD is then graded using a Grading System, most commonly at the moment a 'DaVinci 2k'.from there the film is then printed onto actual film to be duplicated and distributed. Grading generally is done by two people. The colourist, and the director of photography.

Colour correction is absolutly vital. generally i start with ProcAmp on Premier Pro. I correct the saturation, contrast and brightness levels. from their i use RGBCYM corection, with both channel contrast and brightness levels.

Colour correction is very rarely(never being the better word... but never say never) done at the tv station itself during broadcast. Generally if it is a live, or live to tape the production is monitored and corrected(to a point) by the technical director(TD), using camera control units (CCU's) to adjust focus, shutter speed, appeture etc. and various other tools like histograms etc.

This is limited, and not classed a grading, as gradeing is shot-by-shot, sometimes even frame-by-frame correction

I think what Tommy meant was that if you're going to edit some footage that needed color correction, are there standard values for hue, black color, luminance, etc. to get the "right" color?

Can anyone share his/her experience with the color correction tool in Avid Xpress Pro? Thanks.

OK, now I know color corrections are important to make the video good looking. But, that might be a stupid question, how do I know how much corrections should I achieve in each video? And what hue/sat value shold I looking for?
sorry I don't know how to ask the question correctly.

That's not a stupid question at all, and I bet there are a lot of people getting some knowledge from these posts. I'm curious myself.

There is no standard values, or simple answers for video, it is what looks good and experimentation.

however their is a set of limits that outside of which very rarly work with TV's. I generally just judge by eye, but the figures are somewhere, allong with the specific 'Danger' colours for PAL and NTSC respectivly.

For things to be Printed to film there is set guidelines, but im not a trained Colourist.

Just remember a minute setting up your camera properly before each shot will save you about fifty times that in post. You can white and black balance to what you want on camera and avoid problems.

No matter what we're using: film, video, or digital still cameras, we photograph a MACBETH COLOR CHART at the beginning of every tape, roll of film, or series of digital pictures.

Here is what it looks like:

http://www.pictureline.com/photographic/accessories/GretagMacbeth/

http://shop.store.yahoo.com/cinemasupplies/maccol.html

Those colors are the standard. Any color light that falls on that chart changes the colors slightly, and so when you view them by eye, by electronic calibration, or by density on the negative, you can tell how far off the colorchart you shot is from the standard.

When grading, transferring, printing, or manipulating your image, the technician in charge will use this chart to set everything to "zero". This insures that all your colors on the color chart will match up correctly, no matter what media you may be using. (It also insures different media will match up correctly to one another).

From this you can do color manipulation, color correction, etc. And by seeing how far off you are from the original chart in values (in terms of hue, saturation, RGB values, CMYK values) you can then make sure everything you shot is off by the same exact value to match it up.

Of course light is very complex, and there are a lot of nuances, so just because the charts match up, that doesn't mean everything else will, but it gets you into the same area.

You shoot a color chart at the beginning of every tape, roll, disk for calibration purposes later on, but also take a picture of one if the light changse drastically, or if you're shooting in different locations, or if you suspect the colors may be off. If you need to be VERY specific, you can shoot a color chart for every shot you do.

Here's an example of how they use it for standarizing a calbiration:

http://ise.stanford.edu/class/psych221/projects/98/colorConversion/olympus/color_balancing.html

http://www.editorsguild.com/newsletter/SepOct04/sepoct04_macbeth.html

http://www.akdart.com/macbeth.html


There are also grey scale charts to check your contrast in any medium:



the gray scale values are all made to reflect 18% gray values, the black rectangle in the middle is made to reflect NO light, and the white is made to reflect most of the light.


If you are only using video, you use a test pattern viewed through a vectorscope to calibrate you color accordingly from different cameras, decks, footage, etc.

You've probably seen the test pattern, they look like this:



when viewed through a vectorscope, it should look like this:



if it doesnt you adjust the settings until all of those points fall within the little target boxes. (knowing what adjustments to make to get the points to do that is a whole nother story)

To check your brightness/contrast on video, you use a waveform monitor, which looks like this:



here's some more information on adjusting to a color standard:

http://www.wideopenwest.com/~wvg/color%20bar.htm

http://videoexpert.home.att.net/artic2/210stcam.htm

http://www.extron.com/technology/archive.asp?id=vtg300signals

So that's the basics of it. Any color correction or color rendering you do afterwards is a departure from these standards, so if you ever mess up, you can "reset" everything by just going back to these standards. (conforming your media to match the standards)

for pal, the colour bar system is different to that of ntsc.

in tv stations the colour bars are used to ensure that what grading you do counts, and that your colours arent stuffed by differences in gear