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Old April 12th, 2004   #2
Join Date: Feb 2004
Posts: 26
Default Re: Question: How should I optimize video colors for lighting?

Sure - the easiest way is to follow these steps:

Quickie answer: make a new comp the same settings as your clip, drop in your clip, apply Levels, render it out.

Detailed explanation:

UPDATE: I just learned something the other week that I wish I'd known years ago - within the After Effects Project window, there is a New Composition button down by where the Create Folder button is at the bottom of the Project Window. If you drag one (or a bazillion) movies onto this icon, it will create a comp of exactly the correct size, duration, and aspect ratio for the footage. If you drag multiple files, it can create one comp for them all, or individual comps for each file, still exactly right for each one. Huge time saver. OK, skip to step 3.

1.) Launch After Effects and create a new composition, the same pixel dimensions, pixel aspect ratio, & duration of your clip. To keep your life simple, name the composition the same name as the clip. (If you have multiple clips, create a composition that matches the pixel dimensions, time duration, pixel aspect ratio, and framerate of your clip.)

2.) Drop your clip into the matching composition. If you drop it into the timeline window, it will automatically center itself. If you drop it into the preview/viewer window, it will snap to center when you get it close to the center of the composition.

3.) Single click on the clip to highlight it if it isn't already selected.

4.) Go up to the effects pulldown menu at the top of the screen, and go to Effects==>Adjust==>Levels

5.) This will pop up the effects palette. If you are familiar with Photoshop, this effect works just like the one in Photoshop. If you aren't familiar with it, what you are shown is a Histogram, with controls for gamma and black and white points.

A Histogram is a graph that shows how many pixels are what brightness. The far left of the graph indicates black, the middle indicates the range of grey values, and the far right is pure white. The taller the graph is at any point shows how MANY pixels are that brightness.

So if the graph seems all scrunched up to the left part of the Histogram with nothing on the right side, your image has a lot of dark values and not many bright values.

6.) The solid black triangle directly under the Histogram on the left side lets you set the black point. It starts out on the far left, and the further you slide it to the right, the darker it makes the dark portions of the image. Read the manual for a more technically accurate description, but hopefully this gives you the general idea. The more you slide it right, the more it sinks the blacks.

7.) The hollow triangle on the other end (filled with white) lets you adjust the white point. The further you drag it to the left, the brighter your whites get (you know, like Tide....). This will let you blow out the whites if you overdo it.

8.) Then grey filled triangle in the middle is the gamma value. Briefly, this control adjusts the distribution of greys between black and white. The more you push it to the left, the brighter the midtones get. The more you push it to the right, the darker the midtones get. In general, I adjust the black and white values first then mess with the midtones.

As a general starting guideline, I try not to burn or blow out the image. What does this mean? This means I try not to slide the black point so far in that it is beyond where the Histogram tapers out to the left, and the do the same thing for the white point - try not to let it cross the point where there is a lot of graph showing above it to the right. This is just a general guideline. Then adjust the midpoint (gamma) to your liking.

9.) So the image is adjusted, right? Well...sort of. You've just made adjustments to one frame of your image. Now click around your timeline to various times in the clip and see how the image looks, both on your monitor and in the histogram. If you are seeing parts of the graph beyond the edges of the range between the black and white points as you've set them, you are probably buring out the blacks and/or blowing out the whites. This might be necessary to create the look you want, but isn't (always) desirable. Sound vague? It is, it's a judgement call.

So check it at various points throughout the clip and make sure it is consistently satisfactory. Make adjustments as necessary. The way we are doing this now is one setting that will be the same for all frames in the movie. If you know how to keyframe in After Effects, you can get fancier and animate your adjustments throughout the movie. If not, read the manual.

10.) Once you are happy with the adjustment, it would be wise to see how it looks playing back. Press the "zero" key ON YOUR NUMERIC KEYPAD (the other zero key doesn't work for this) to render a RAM preview of your movie. Watch it play back and make sure it is satisfactory. If not, go back to step 6 and repeat as necessary.

Rinse. (I'm kidding.)

11.) Happy? Then press Command - M to render out the movie. Make sure the file is named the way you want it and is going to save it where you want it to go. Make sure the Output Settings are Render Settings are the way you want them. I'd recommend Best Settings and Lossless.

12.) Press the Render button on the Render Queue window to begin rendering. This will render out your digital master of the file.

13.) Using a product like Cleaner or Compressor, compress that movie to the desired codec. There is more information about these tools elsewhere in the forums. If you don't have these products, just open it up with QuickTime Player and Export it to the desired codec. We recommend DV or PhotoJPEG 50%. More on these elsewhere as well.

14.) Drop the file into your Catalyst Library folder with the rest of your media (rename to put a number from 0-255 in front of it if it doesn't already) and you're ready to rock. Or project. Or whatever.
mikecurtis is offline   Reply With Quote