Home of Professional Cinematography since 1996

On Set Colour Correction

Published : 26th August 2003


Given the string of pros and cons for having a VC/Colourist on set, the BIGGEST "NO NO" is to put the grading in the hands of the DF/Recordist (nee Videotape) Operator. Sure, given the nature of a film style work flow, it seems logical that the DP would drive the grading operations of the DF, but I am reasonably positive that won't happen most of the time, as the DP will be too busy to actually sit down and drive the DF. Instead the DP will, invariably, "guide" the DF operator to do what he/she wants, and, in my direct experience, that is the case, with the DF operator invariably, influencing the grading.

Since the work flow of the Viper/DF implies an uncorrected, film style work flow, we would usually, at maximum, choose to have a DIT on-set, but not to include an experienced VC or Colourist, so why would we put even a rough color grading in the hands of a DF Operator or DIT who, if we are honest about the typical recordist/operator or DIT, has very little grading, colouring, or video control experience? That's part of my problem with putting color grading on the set in this manner.

Just as damaging to a color grading, I have not seen any evidence that the current DF screen is adequate for even a rough color grading, given its construction, contrast range, and colorimetry. Especially when placed in a typically poorly controlled on-set color correction environment. The only acceptable screen (for any kind of critical color viewing) would be either a high quality CRT or one of the new generation organic LCD's. And even with optimum monitoring any reliable color grading can only take place in a trustworthy on-set viewing environment, virtually impossible on a typical shoot, with DP’s walking in and out of that area from and to lighting conditions (from daylight, to HMI, to tungsten, to ???) which will destroy any sense of visual colorimetric continuity or accuracy, thence any reliable on-set color grading.

Every experienced VC or Colourist or DIT (with a VC background), such an environment can be created, and has been used very effectively for many years, but is usually eschewed by film style adherents in favor of space, speed (of work flow), set ergonomics, or simply, lack of crew expertise. Though I know I can't speak to European modes of operation or operational pre dispositions, the scenarios I describe are exactly what have happened so far in the U.S. Given the folks I have seen training as new DF recordist /operators, most with very little real on-set experience, the on-set viewing ergonomics, and the efficacy of the critical color monitoring equipment currently employed with the DF, I have every reason to strongly believe that that those scenarios work together to undercut the intelligent use of the DF for even rough on-set color grading in the U.S.

Such resultantly unreliable rough grades simply add cost to productions without any real benefit to the production, and that any production that would choose 4:4:4, uncorrected HD/film style Viper/DF work flow, should think twice before mixing their corrected/uncorrected metaphors.
Having made the choice to pursue uncorrected, film style workflow, just test shoot and grade, then shoot using that traditional work flow, then grade it in post.

GEORGE C. PALMER
HDPIX, INC.
HD and Digital Imaging Services
www.HDPIX.COM
www.angenieux.com



With the power that one can posses with post color grading systems like the Davinci-2k, the Lustre and heck, even with AVID DS, Shake or Color Finesse.

Why would anyone in their right mind want to try and color grade in the field?

To me this is as silly as saying that since you can put film lenses on a Canon XL-1 why use a Viper?

Another often overlooked aspect of this is that often certain things will be done during shooting in order to facilitate a better working image to achieve certain looks after a post color grade that would not otherwise be achievable with straight on set controls.

The simplest is something I have done for years with video and that also works even better with HD, raising the blacks and then crushing them in post. In fact, what I have been doing is very similar to what Kodak does with film during the line to log process used for converting 35mm neg to digital. On set the image looks murky and washed out, but after post it has a much wider dynamic range than you could get. This is of course similar to flashing and perhaps even pushing film.

There are so many variables with on set color grading.

1/. The DP has enough to do with their camera and lighting crew let alone deal with someone else affecting their image and vision.

2/. It is nearly impossible to create a viewing situation in the field anywhere close to a properly configured and calibrated professional grading suite.

3/. With the stresses of set, why be adding yet another step to getting the shot, that will then ultimately get rushed and potentially messed up. It adds time to the schedule.

Why pay a whole crew to sit around while the color gets tweaked? That would be so much more expensive than a day or two in post.

4/. If you color grade in the field, that is it. In post, you can apply and undo, and reapply. If you have an image in the middle, you can go in any direction. Given the time and budget, you can get very exotic in post, cutting masks for certain areas, adding light to just an actors eyes. This kind of artistry takes lots of discipline and time. If you are going to color grade on set, would you just as soon bring an audio mixing suite into the field as well? To get ADR and Foley sounds and live mix everything in surround as you shot, since most of the cameras can record 6 channels of AES/EBU 24-bit audio?

Heck while your at it, you might as well edit as you shot, and then not have any post costs. In fact, why have pre-production at all, lets just bring the conceptual artists to set and have them draw up sketches right there, and then the costumers can staple the costumes together...I think you get the idea, some things are better left to different stages.

Just because you can, doesn't mean you should, or that it is more advantageous to another option. The questions need to be what is the most efficient way of getting the desired end result.

Brett Shapiro



>The simplest is something I have done for years with video and that also >works even better with HD, raising the blacks and then crushing them in >post.

...which is a problem if you have a director and/or producer who don't have a lot of confidence and are getting nervous looking at washed-out images day after day. At least if there was some sort of rough grade on a monitor (such as the Viper's 4:2:2 output) some confidence could be restored.

>There are so many variables with on set color grading.

True...unless one knows in advance that the only place grading will take place is on the set.

>If you are going to color grade on set, would you just as soon bring an >audio mixing suite into the field as well?

I've worked on low-budget features where they spend more money in post on the audio than on the image. Not every project goes through a color correction process. If one knows in advance that this will happen, great; but for the kind of HD projects I've been shooting they'll never see a color correction suite. I have to color correct on the set or location.

If nothing else I think someone should be there maximizing the dynamic range of the camera during the shoot. I don't think color correcting on the set is the best way to go, but I definitely think that the "set it up in prep" model is flawed based on my experience working with a video controller in the field.

Art Adams, DP
Mountain View, California - "Silicon Valley"
http://www.artadams.net/



>,,,,,I don't think color correcting on the set is the best way to go, but I >definitely think that the "set it up in prep" model is flawed

Aren't you contradicting yourself here?

If you equate *colour correcting* with *video controller* then what you're saying is confusing.

This technology is evolving and we need to be open minded about the semantics. I think there has been a lot of swish put on the role under discussion - on set manipulator of camera set-up - shader, colourist, video engineer, DIT, DOP - whoever does this. They are doing the same thing in an on-set situation.

The extent to which they do so is a matter of personal taste - and skill set.

As (I hope!) things tend towards *uncompressed*, I think we'll see less and less on-set camera set-up manipulation. Particularly in terms of full time crew positions. It may be better to have the time, talent and means to have an on-set *person-who-improves-the-picture*. But I don't think in five years it will be as often seen as it is now.

David Perrault, csc



>Aren't you contradicting yourself here?

Not necessarily. Immediately before that quote I spoke of how I would always want someone on set who could adapt the dynamic range of the camera to encompass whatever I happened to be shooting. They could also rough in the color by doing a rough white balance and do some basic shading while making sure the gamma was neutral and the ped wasn't crushed.

As long as they weren't doing anything that threw information away I think I'd be better off than if I just sent an image with a pre-production-determined preset to post. This, of course, doesn't necessarily apply to the Viper, although I do like the idea of the roughly correctable output to rough in an idea of what the scene will look like so the powers that be don't freak out at the consistently green and washed out image.

Art Adams, DP
Mountain View, California - "Silicon Valley"



David Perrault wrote:

>As (I hope!) things tend towards *uncompressed*, I think we'll see less >and less on-set camera set-up manipulation.

I agree, this is the way of the future... much more film-like in workflow. But I suppose one could lay on a DIT to color correct a film camera's video tap output.

(No disrespect towards DITs intended.)

Jeff "dit-duh-dit-dit" Kreines



David Perrault wrote:

>As (I hope!) things tend towards *uncompressed*, I think we'll see less >and less on-set camera set-up manipulation.

Compression or lack of it is not the issue, although many people seem to think it is. The issue is manipulation of the information coming from the camera to the recorder - whatever recorder is being used. The philosophy of the Viper is diametrically opposed to that of Sony, Panasonic, and any other standard video camera. In the "traditional" video camera model, the image emerging from the camera is expected to represent the final look of what's being captured. In order to do this, gamma correction and other color manipulations are applied in the camera. The Viper does away with all of this and simply provides an output that is representative of the original capture, without regard to creating a final product, at least on the FilmStream output. It then encodes it in 10 bit log space to best preserve the full range of capture. The beauty of this is that with the proper LUT applied, this image can and should look like a reasonable facsimile of the final product on any monitor that can display it.

None of this, however, has anything whatsoever to do with compression.

Mike Most
VFX Supervisor
IATSE Local 600
Los Angeles



Michael D. Most wrote:

>None of this, however, has anything whatsoever to do with >compression.


True, if you're defining compression properly, which you of course are.

However, many also would consider Sony's decimation of the HDCam image (3:1:1) to be a form of compression, as it's intended to reduce the amount of data the system has to handle. The same could be said for Sony's horizontal "over-sampling" -- as you're only resolving (on tape)1440 of those 1920 pixels. While it's not technically "compression" it's really the same thing, de facto -- as it permits one to shoe horn an image that would ordinarily fill a one gallon jug into a hip flask.

(Perhaps my clumsy metaphor needs to be stirred, not shaken?)

It's hard to regain what's lost in gamut from that 3:1:1 image (which, again, many consider to be a form of compression) if you need to do extensive color correction in post. Were that not the case, Sony wouldn't be coming out with 4:4:4 recorders.

>The philosophy of the Viper is diametrically opposed to that of Sony, >Panasonic, and any other standard video camera.

Yes. Sadly, the philosophy of Director's Friend is not diametrically opposed to that of the Ryder Truck Company... it's a bit big for many types of location shooting. The Viper is a wonderful idea, a great leap forward in conceptual terms, but as the system is presently constituted, I don't see it being used for much more than effects work on stages. (Yes, I know about Russian Ark...)

Jeff "waiting for an HD camera/recorder (uncompressed, of course) the
size of my A-Minima"
Kreines



>The Viper does away with all of this and simply provides an output that is >representative of the original capture

It'll be interesting to see how the following conversation gets resolved on Viper sets:

Director: Where's the monitor?

DP: There's no monitor.

Director: Whattaya mean, there's no monitor? This is HD! There's GOT to be a monitor!

DP: There's no monitor for this camera. You shoot it like a film stock. We'll see dailies.

Director: Dailies? I thought HD was supposed to do away with all that stuff? I want to see what I'm getting RIGHT NOW!

DP: If I showed you an image on a monitor it would end up green and low contrast. Better to see dailies.

Director: You're making my project GREEN? Where's my cell phone...

Art Adams, DP



>DP: If I showed you an image on a monitor it would end up green and >low contrast. Better to see dailies.

While this may be humorous, it's not true. The Viper provides a full time corrected HD output in addition to the FilmStream output. That's what you display on the monitor.

Mike Most
VFX Supervisor
IATSE Local 600
Los Angeles



>While this may be humorous, it's not true. The Viper provides a full time >corrected HD output in addition to the FilmStream output.

And... who does the correcting...?


Art Adams, DP



> And... who does the correcting...?

Well, amazingly enough, unless you're going for some strange color effect, and assuming you're using proper filtration for color correction if you're not under tungsten light conditions, the image comes up properly balanced and the brightness or lack of it is driven by your lighting and exposure choice. I believe you can also get a paintbox from Thomson, but as with Polaroid photographs, it just seems right most of the time, probably because the mixing of the RG and B channels is not being mucked with in the first place.

Anyone with more experience than I have in looking at the HD feed from the Viper feel free to chime in here. Mark? Geoff? Joe?

Mike Most
VFX Supervisor
IATSE Local 600
Los Angeles



Jeff Kreines writes:

>Jeff "waiting for an HD camera/recorder (uncompressed, of course) the >size of my A-Minima" Kreines

An Apple laptop with the Magma expansion chassis and a CineWaveHD card fits in a shoulder bag, not all that bad really. Then there's the CineBricks that can hang on your battery belt. Not quite A-Minima sized, but you don't need the Ryder Truck.

Scott Billups - LA



What's a CineBrick?

Dale Launer
Writer/Filmmaker
Santa Monica



Scott Billups wrote:

>RAM recorders. Saw a number of them this week @ CineGear

Do they still cost about $20K?

Jeff Kreines



Dale Launer writes:

>What's a CineBrick?

RAM recorders. Saw a number of them this week @ CineGear and Plus8Digital.

Scott Billups
LA



Mike Most wrote :

>Anyone with experience in looking at the HD feed from the Viper feel >free to chime in here. Mark? Geoff? Joe?

Hi Mike,

I am comfortable looking at the Viper output, whether raw, through the "Cinematographer's Friend" or down converted. Just like learning to use a contrast viewer, or looking at uncorrected Cineon files, you learn to make distinctions, and you get used to it.

Dave Stump ASC
VFX Supervisor/DP
LA, Calif.



> Well, amazingly enough, unless you're going for some strange color >effect, and assuming you're using proper filtration for color correction...

Original versions of camera software did exactly what Michael alluded to. Future (near) versions will allow more customisation of that output. That output intended for monitoring only and has now (with more promised) the ability to show something much more reasonable than the greenish look of the dual-link output. Even that dual-link output now looks a little less greenish in a post NAB software release. As for the "CRP", it works fine on the LDK 6000 version of the camera but I haven't tried it on a Viper as yet.

GEORGE C. PALMER
HDPIX, INC.
HD and Digital Imaging Services



But then it's possible to get much of the way there using a CRT monitor. We ran some tests on our software correction (cineSpace) where we sat in a screening room with a print of a selection of shot looping and the digital version of the same on screen.

The only place where this breaks is on the really saturated colours which either get clipped or compressed back into range depending upon how you choose to handle them. Other than that, is was closer than anything I've ever seen (you'd need to make your own call on this though so I'm not just flogging our stuff!) .

The result is considerably better than looking at the files raw, which should surely be a consideration when you have uneducated eyes to consider on set.
The colour saturation issue can be solved by dumping the CRT monitor and shifting to a different technology (maybe Accuscene?)

We've recently timed a DI from Spirit using the version of cinespace that's built into the DaVinci 2k Plus Data and the film required no trims at the print stage to the one negative that was shot out. What's missing for us in the Viper workflow is someone to build the hardware into which we can put the software... Any hardware folks out there looking to build a solution?

Tony Clark ACS
Rising Sun Pictures
www: http://www.rsp.com.au



Tony Clark wrote:

>The colour saturation issue can be solved by dumping the CRT monitor >and shifting to a different technology (maybe Accuscene?)

Have you actually seen Accuscene?

I spent a lot of time looking at it at NAB and was a bit under whelmed.

Jeff Kreines



>Just because you can, doesn't mean you should, or that it is more >advantageous to another option.

Brett, have you ever heard of Robert Rodriguez?

Everything you said can’t or shouldn't be done…he does, quite effectively. The big reason is well stated in your last line "Most efficient way of getting the desired end result". For me the most efficient way is Get as close as practical/ possible on set go the rest of the way in post when available/necessary.

I wrote a post a while back "H-D All of the above" then reposted a similar philosophy a few weeks ago.

Your post here seems to overstate the apparent problems and you may not really see the practical wisdom behind that which you condemn.

Everything you mention BTW will someday happen in the field on the set LIVE
and sent to the audience.

As an Analogy :

For example when a Studio Musician buys a Guitar off the shelf. It came from the Factory. Does he make the assumption that its tuned already as good as its ever going to get???


Then does he just plug it into the recording studio and play the song then look to the engineer and say that now every note can be adjusted to sound the way the engineer wants it to sound later???

The engineer would likely not be as excited at the requirement of FIXing every single note rather than taking that same time to ENHANCE the overall sound. Recommending that taking a few minutes to "use the tuning nobs to make the proper sound" would be best.

A little tweaking (Lighting, Filtering, White balancing) on the set can save lots of time in post later and creates a much better image to start with. Its OK once you get the hang of it its not that complicated.

And is after all a practical Art.

Remember Vanilla is also a Flavour. Its a Lie to say that whatever you do you can't undo later so do nothing so you can do anything. Truth is doing nothing is itself doing something and you may not be able to recover from Vanilla to get where you want the images to go.

Take control of everything you can whenever you can to achieve the best
images at every stage of the game.

Then again the more people take the do nothing Philosophy the less justification we have as professionals for being on the set. Why does a Director need a DP, or a Engineer/VC/DIT, at all if she intends to fix it all in Post?

"Fix it in Post" the Battle Cry of the Incapable.

B. Sean Fairburn
LA DP



Tony Clark wrote :


>The colour saturation issue can be solved by dumping the CRT monitor

Could that different technology be some flat screen display (Apple cinema display for instance) using your cineSpace software ?

-Sam Wells



Sam Wells wrote:


>Could that different technology be some flat screen display (Apple >cinema display for instance) using your cineSpace software ?

Possibly. LCD and plasma screens would seem to offer wider colour gamut’s and therefore be capable of showing more of the colour range of film, but have odd off-axis viewing problems which make them tricky to use in colour grading. I think they'd make good on-set monitors though; lightweight, wide gamut, high resolution, etc. Just need to keep your head cantered on the screen!

Tony Clark ACS
Rising Sun Pictures



Jeff Kreines wrote :

> Have you actually seen Accuscene?

No, but the concept should work as it's a display with a very wide gamut, which if driven with a correctly built 3d LUT should produce decent results.

What in particular was it that didn't work for you?

Tony Clark
Rising Sun Pictures



Tony Clark wrote :

> What in particular was it that didn't work for you?

Size, aspect ratio, clumsiness (external board). Nothing to do with gamut...

Jeff Kreines



Art,

The simple solution for a director or client who cannot understand the concept of the Viper is to feed them the "video tap" output in black and white. Tell them it's just like a film "video tap. " The image really sucks whereas the final color corrected image will look great. It is pointless to send the raw output to anyone other than the DP. If the client has to see a color image then the 4:2:2 HD-SDI might be more suitable as long as they don't start to second guess the DP.

I recently finished an Saab spot in which the director used both HDCAM and 35mm film. After I spend some time looking at the agency monitor which was a feed from the film video tap I was amazed that no one complained about the film "video tap" which was three stops overexposed with grain the size of golf balls. If clients can understand that on a film shoot the "video tap" does not represent the final image than I can't see why Viper clients could not be trained to do so also.

Based on my test shoot with the Viper I foresee the film DP's will choose to shoot without a monitor and maintain the same techniques used for shooting film (on set monitor will be strictly "video taps".)

Tony Salgado



I have not worked with the Viper as of yet but have worked with over 4000 RAW still images in the last 2 years. If you modify settings in a non controlled environment you almost always regret it.

Shoot at the optimum electronic settings that have been set for the camera (ie: RAW) being careful to remain in the dynamic range of the electronics (exposure levels). Use the on set monitor for framing, rough focus and VERY rough color balance being aware that lighting conditions on set will greatly influence on what you see on the monitor.

If you truly want to see what you are getting in Digital Cinema, PROJECT IT! Suddenly you will see why dailies matter and shooting RAW will save your ass. At least with RAW you can tailor what you want without destroying the original. Think of RAW as the digital negative and you won't go wrong.

My 2 1/2 pence

Mark Forman
Mark Forman Productions, Corp
http://screeningroom.com
"Screen it and you won't go wrong"



Mark Forman wrote :


>I have not worked with the Viper as of yet but have worked with over >4000 RAW still images in the last 2 years.

Earlier in the year I shot a series of stills for a project and had the option of using RAW files on the Nikon D1x. I chose the JPEG because of my, and the editors, unfamiliarity with the RAW format . Is RAW a standard still photo file format or a Nikon proprietary file format? Is RAW available as a video file acquisition format? Is there any special software needed to integrate RAW files into video editing programs?

Thanks.
Jim Sofranko
NY/DP



>I chose the JPEG because of my, and the editors, unfamiliarity with the >RAW format

Once you go RAW, you'll never go back!

All of the manufacturers have RAW formats, but I don't believe they're all compatible - you need the appropriate software to turn them into files everyone else can use. May seem like a pain, but the advantages are well worth it.

For instance - if you were shooting JPEGs, it probably took the camera 4 - 5 times as long to save each shot as it would have to save the RAW files - the camera doesn't have to process & compress the image, it just saves "raw" information directly from the CCD.

For this same reason, RAW images are actually smaller than, say, uncompressed TIFFS... yet they contain all the information, if not more. Most importantly, RAW files allow you to defer all of the signal processing until the editing process. That means everything from white balance to exposure adjustments to gamma curves, essentially the software does everything the camera head would normally do, using the RAW files as input. I believe you can effectively get an increase in exposure latitude because of this...not to mention much better colour reproduction in unusual lighting conditions.

I don't know that there's any way to use RAW files directly in video editing programs... but generally the photographer edits the RAW images and supplies the client with whatever format they need for their application. I like this because I get to edit my images before anyone else can see them.

George Hupka
Director/DP, Downstream Pictures
Saskatoon, Canada



Jim,

RAW is not a standard still photo file format but a Nikon proprietary format. Nikon do supply a plug in for Photoshop that comes within the Nikon Software (Nikon view) supplied with the camera. My computer takes over two minutes to convert one RAW file to TIFF.

You will have to go through Photoshop to convert the RAW files although After Effects may be able to use the plug-in. I would suspect no Video Editing software would be capable of reading RAW.
The RAW format is alien to video although the Viper data stream shares a similar philosophy.

Tom Gleeson D.O.P.
Sydney Australia


I really enjoy shooting RAW in stills with my Nikon D1x and D100 because it does give me the control I need in post processing which can yield fantastic results.

White balance is not an issue for me since I can do it later without worry. Issues that are very important are exposure levels and dynamic range especially when dealing with highlights. Digging into the shadows is one of the great things that can make a seemingly under exposed image truly pop out.


For RAW to work successfuly for digital cinema I think we need to incorporate NON DESTRUCTIVE look up tables for each kind of display to simulate what the finished scene would look like. If you have a Plasma a CRT or DLP each should have its own LUT swiched in post not on the digital negative.


All displays should be standardized since projecting is such a crap shoot now. Each manufacturer seems to do it own thing with very mixed results even among similar display types such as DLPs . So it is up to the DP to get framing, moves, lighting and exposure levels and set color right and get a RAW image onto the recording media using an on set monitoring system set to an idividual monitor LUT. Once that is done the DP can go into post and time and produce a initial working editorial copy similar to a workprint never changing the original RAW files. Timing metadata would be added at this time for future reference. The cinematographer and colorist should work together to produce a final release print which has all the changes needed which isalso recorded in additional metadata.

>The beauty of RAW is that it is thesame as a negative in that you always have an unchanging base to work fromwhich can take advantage of future imprvements throughout the chain.

Mark Forman
Mark Forman Productions,
http://screeningroom.com