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| "A prime example of using color grading and effects to make an image and scene better" - KERBEROS Directed by Kely McClung |
Over the past several years, doing the post processing on BLOOD TIES and several music videos, my short film AM SESSION, and starting in on KERBEROS, many people have asked for advice and help in tackling the color correction and enhancement of their own projects. I hope this page can help and at least point some people in the right direction. Note that I realize that that direction may be different than the one I am going, and that there are other talented people out there, some with more skill and experience, and certainly better tool sets, but maybe some one can benefit from this basic advice.
Some people do not have After Effects (my tool of choice right now). Cameras will range from cell phone video to the RED and Varicam's and Viper's. I did several years experimentation with earlier 1 chip miniDV cameras before I felt comfortable tackling BT. BLOOD TIES was shot on DVX100. So was AM SESSION, which I sold to HBO. KERBEROS is being shot on the Sony EX1. These ideas and approaches are meant for all. (or course if you are shooting on a Viper you are probably doing your color grading on a Da Vinci... with power windows and real time capabilities).
I work on uncompressed footage. I understand that it was radically compressed when it was captured to fit the compression schemes of the cameras, but I edit, then export my scenes to either Targa or Tiff and work on the full rez image sequences. I tend to work on Targa these days as it seems to be more universally accepted by some of the higher end editing systems. Once my color correction is done, my grading, adding shadows, vignettes, post diffusion, noise reduction, and of course any effects - smoke,or particle fx, or flashes of lights, and have manipulated my transfer modes to increase the original resolution - not by adding back the original image lost but creating a new image, I want to work and stay in an uncompressed format. For my own edification, I have imported a tiff or tga file, exported it again as a new file, imported it again, and maybe made that trip as many as 10 times just to determine that it indeed does not change on a pixel by pixel level. (Blow up in Photoshop to 3200% and checked pixel by pixel)
Once an image sequence is brought into After FX, I now have to split the sequence into individual cuts. A bit of a pain, but not near as hard as it sounds or as time consuming. Still, each cut becomes it's own layer, and so as fast as my edits tend to be, a 3 minutes scene can easily become a hundred layers or more. It's one of the reason I work on my films scene by scene. This sequence will be color graded, fx added, tweaked, and then rendered as a single image sequence to be brought back into my editing program - (Premiere) and laid above the original edit. As long as you've kept your output consistent in export to import to export with the frame rate - it will all line back up perfectly.
I also letterbox in post, re framing as necessary in order to make subtle adjustments to my story telling. i.e., I have two actors speaking and want one to be dominant at the first part of the scene as the other gets stronger and takes a more dominant position near the end. I would establish an eye line that helps the consistency of the cut but perhaps lets one actor's eyes be slightly higher in frame. By the end of the 3 minutes, the other actor may have gradually gone up in frame. Perhaps it is only a difference of 20 or 30 pixels total, but it can make a difference on a subconscious level to the viewer. Other times, the eye line or compositions point of interest is so different from one cut to another (especially on hand held action shots) that by raising one cut and lowering the other, the focus (point of interest) of the shot itself can be made to match much more closely, and a cut that looked jarring suddenly becomes perfect. It's one reason that BLOOD TIES, with its hand held BLAIR WITCH style camera work, still comes off so smooth and controlled.
Scrolling through the sequence, I'll determine a couple reference frames - maybe at the beginning or middle or maybe not even until he end. I'll correct those first and then use those as the reference to match or create the rest of the look. I'll also look for problem shots. Once in while, I will have a light or prop or something creeping into the edge of my shot. I can of course enlarge and re frame to remove it - but this is a last resort as my image quality will go down by enlarging. Still, you can probably get away with up to a 10% increase with very noticeable little damage.
I'll also try to determine really problem shots or ones I want to recheck - comp markers can become your good friend as you work through the file... Also After FX snap shots...
If for some reason - and it happens - I can not make my shot look right - I'll export the reference frames into PhotoShop - work there - and then import it back as the reference or goal to where I am going.
Using PhotoShop is also the typical way I work on other people's projects. I will not spend the time with them over my shoulder on the more time consuming effects program, but if they are either in my studio or in a remote location, we can quickly establish the look that we are going for and the goal of my work within After FX.
While there are comparatively few books on color correction for film, there is endless information for PhotoShop. Almost anything you can do in PS can be done in After Effects, and the principles are mostly the same for Apple's Color, or even Scratch and Da Vinci systems. Their tool sets and interfaces can be radically different, but the concepts, and end results can be remarkably the same. If you are an independent filmmaker, I encourage you to spend a lot of time with Photo Shop.
There is information out there to be found, (here is one of my own bookmarks by Stu Maschwitz ) Acting is not for everyone. Stunts are not for everyone. Writing is not for everyone. And neither are FX and color grading and correction. What one needs to understand is that like anything we do, not every one is suited for every aspect of film making. For me, my goal is to someday be the guy with the least amount of talent and experience on the project, being able to benefit from everybody else's superior skill sets. But for now, I am making movies, and at least trying to compete.
While I can make pretty fast decisions on the tools I use for each cut - and I frequently have to use a different formula for every single set up and shot, I do tend to have a relatively consistent approach.
I will usually start with levels. I use curves as well but I start with levels so as not to create color shifts just yet. One of the things you'll notice on AFX is that the effects you add are non destructive - so you do not have to work on adjustment layers, though sometimes they'll help in your workflow. Remember, you are remapping the histogram of the pixels, and it's easy to get carried away and degrade the image. Still, we are usually looking to create clean, noiseless blacks at this time.
A simple tip if you want to see how much you are messing with the histogram of the image is to place a levels adjustment on top of the layer, and then use it only as a reference. So now add another levels effect and make your adjustments in it. Gaps and fractures in the histogram are pretty good indications that you are degrading the integrity of the color space, and may show as a loss of resolution.
I frequently use color balance - though the controls are not as easy to use as primary and secondary color wheels that are found in some programs.
On KERBEROS, I find myself more relying on Hue/Saturation to remove color casts and remap colors. A bit of any one or multiple colors can be desaturated and I find it easier to create more pleasing colors. Like all the fx, it's easy to get carried away, and you may easily find yourself adding to the apparent graininess of an image, (by overdoing the desaturation - you are leaving more pixels dark which are read as noise) so investigate remapping and adjusting the hue of specific color range before desaturating.
It's a personal preference as much as anything, but I rarely add to the saturation of any color. Video tends to look more film like to my eye when it's dialed down. Film gets away with it much more, look at Jeunet's rich work or the nearly experimental looks that Tony Scott sometimes uses in very commercial projects, and of course a million commercials. I love rich vivid colors, but the films I am shooting on video tend to benefit from the rich browns and blues, and i try to add splashes of color to my set design and wardrobe choices, then emphasize them in post.
I will occasionally add post gels - in After Fx, I find myself using CC Color grad almost as added light - using the 4 quadrants of color to either emphasize, add, or counterbalance color in the scene. Of course. these are manipulated with transfer modes and very low opacity, and the position of the colors moved to accommodate. It can be very subtle, yet to my eye make major changes to how the scene is perceived. Sometime, the light is to help or correct, other times the splash of blue light I am adding to the side of a building is there only because I think it looks cool, or add a splash of color where there otherwise wasn't any. And sometimes, it's there into giving the scene a look as if we took more time than we had to light and bring in the artistic side of the DP work we would of done if we had more time, resources and money.
Also investigate the use of solids layered on top, and then controlled with transfer modes and opacity.
If the picture lacks the punch or impact I want, I may be able to get a bit more with Curves. The classic S-Curve can help bring some extra ummpphh to a shot, and sometimes the S is subtle enough to seem like a straight line. Still, I frequently make a pass with it. Again, check the histogram of your reference levels adjustment to see how you might be degrading the shot.
Sometimes, I add, or at least try to add a photo filter, generally for removing a color cast or particular color more than enhancing it. But it is easy to flip from one filter to the other and 'audition' basic looks as you determine the look of the scene.
Investigate glows and post diffusion filters. My expanding and filling blown out highlights, I have saved many over exposed shots, that resulted from our guerilla style filming using natural light.
I frequently use masks to limit or control correction to a particular part of the frame. The easiest way for me is to duplicate the frame, cut use a mask to limit the area, feather it, and either apply various fx and/or transfer modes. I may easily have a half dozen masks, and if the camera is moving like mine almost always is, they will have to be tracked and animated, though generally speaking, they will not have to be pixel perfect tracks.
I frequently use transfer modes. I have done a lot of experimentation, and many times, even when a shot is near perfect. i will duplicate it, use a transfer mode, dial down the opacity (sometime to just 2 or 3 %) and be happy with my result. There are some shots that benefited from several layers done in this way that in combination, created the final shot. By combining information and remapping pixels based on some of these modes, I increase the resolution and color space of the clip. Again, please note that I am not saying I put back information that was lost in acquisition, but am creating new information that when combined with what I have makes the image better. So while no longer being the original shot, it is an uncompressed. 4:4:4 color image. It's the talent, experience, taste, and effort that will determine if it's good or better that what was originally shot, but technically it certainly can be.
I look at every shot I do and spend time trying to make it better. A shadow, a light, a touch up, a hint of new color, the enhancement of an existing color, re framing, resizing, all go a long way into adding to the look that we wish we could have accomplished in the first place or maybe now have an even better idea of how its look can be modified to better fit the context of what we are saying.
I would say one of the biggest mistakes I see in beginner's or amateur looking work, is in trying to do to much too quick. The really good work is usually a result of multiple processes, and several small adjustments. Sometimes, it is very, very subtle changes and influences that create the most dramatic and effective work.
I will post more when I can - I do have suggestions on how to brighten or darken, on how to correct or augment our shots. I have my own ideas and opinions of video noise reduction and have discovered the hard way some of the work flows and 'gotchas' of working with such massive amounts of information. (BLOOD TIES exist in it's original form, then a half dozen incarnations on its way to completion of 192,000 uncompressed tga files, each one batch processed scene by scene in PhotoShop - more on that later - and of course this is just the image - I spend at least equal time and effort on the sound - the adr, the Foley, the sound design, and the mix.
I intend to post some of the more radical 'saves' I have done on my own projects so as to help illustrate the possibilities you might encounter on your own.
I'll also try to post the work flow and advice on typical fx in my work (gunshots and the like). All gunshots in BLOOD TIES and most in KERBEROS were done in post. After all, my huge crew of 2 and I were filming in foreign countries without permission or permits. The YouTube version of the trailer doesn't do much justice to it, but I did see it on the 60 foot screens at Disney during the INDIE FEST USA FILM FESTIVAL. (which it won Best of Festival) It looked amazing! I'll try to re encode and post a high quality version of it soon. One of the highlights of that fx work was on my last trip to Thailand, where I showed the film to Tony Ja's director and producers, that they encouraged me to spend less money on guns and put some toward helicopter shots, explosions, etc... They were more than shocked when I confessed that I spent less than 100 dollars on some plastic guns in Bangkok's ChinaTown!)
Hope some of this helps, even if just lets you communicate better with someone who knows more and can do the job for you.
Back to making movies!
kely mcclung
Color Correction and Desktop Grading examples from KERBEROS
KERBEROS Title Sequence Stills designed by heAring eYe doG cReatiVe with both thumbnails and reduced to 50%image size jpeg renders exported from uncompressed tiff's at quality 7