Using DSC test charts??

[Alex Raskin]

I'm new to this. We recently invested in your CamAlign FrontBox HD Pro chart. I'm trying to figure out the workflow now, please help.

Our camera is SI-2K Mini. It captures in Cineform RAW format.

Since the footage is RAW, it looks washed out by default. In-camera, there's a way to apply LOOKs to grade the footage on-set.

LOOKs can also be carried to, or applied/changed at, the post-production stage.

I was assuming that with the chart, I should take the unprocessed RAW video (without any look applied in-camera), and apply CC in post to arrive at the correct contrast and colors as per the reference chart.

Using After Effects with Color Finesse, I was not able to achieve acceptable results. When I set White and Black points in Curves, contrast increases as it should; but when I set Gray point, colors become posterized and wrong.

Also I am not clear what exactly should I do to "put primary colors in their respective boxes on Vectorscope". Whatever the adjustments, colors seem to be maybe 1/3 of the way, close to the center.

What exactly is the workflow of using the CamAlign FrontBox HD Pro chart with the cameras producing RAW images; or for that matter, with any cameras. What is the difference between trying to set the looks on-set vs. in post.

Our goal is not to tweak the image but to produce the most faithful representation using the chart as reference. So far I've failed. Please help.

[Peter Moretti]

Does the camera have a vectorscope so you can adjust the on set look to accurately place the primaries in their proper boxes in the vectorscope? Then I would think you could use that look in post.

To be honest this sounds more like an SI2K ? than a test chart one. I'd post in the SI forum here.

HTH a little.

[Alex Raskin]

> this sounds more like an SI2K ? than a test chart one. I'd post in the SI forum here.

I did, not much luck so far - but it's only been a day.

But in fact I don't want this to be camera-specific. Especially since my cam outputs RAW files, post processing workflow is what I am interested in, not on-set. Thanks.

[Peter Moretti]

Alex, but w/ the SI2K I would imagine you'd want to set the look on set if you have a test chart w/ you. That would be the beauty of being able to set the look on set and copy it off the camera for post.

Anyway, in general, you should be able to use the CC tools in your NLE to bring the primaries into their proper boxes on the vectorscope. If you're not, then it may very well be an SI2K specific issue.

[Alex Raskin]

SI-2K's software includes a limited-functionality copy of the Iridas grading suite.

Unfortunately, it looks like the vectorscope does not work at all, and the color match function is absent.

So it does not seem feasible to set the look in-camera using the chart as exact reference.

>> you should be able to use the CC tools in your NLE to bring the primaries into their proper boxes on the vectorscope.

Could you give me an example of the workflow using After Effects?

Or PremierePro, if you really want to stay with NLE for color grading...

Thanks

[Peter Moretti]

Alex,

I don't use those programs, but what I do in Avid should be similar. Essentially you adust the Hue Offest Wheels and/or Curves levels until the primary color dots on the vectorscope fit into their respective spots on the graticle (overlay that has the little boxes).

The thing is that with a normal recording, they shouldn't be that far off to begin with. With RAW, you are getting washed out looking colors, so you have to apply a stronger look, but it still should be possilbe. I'm just surprised that there isn't some preset or look already made to get things close to home.

I would also post on the Cineform forum b/c SI2K uses Cineform RAW, so they may be able to help you as well.

Also, you may want to post a screen print of your vectorscope of the CamAlign shot.

[Alex Raskin]

Thanks Peter, this is very helpful, I will try to post a Vscope screenshot later today.

The problem might be that my software vectorscope (Synthetic Aperture's Color Finesse 1.5.7 for AE 7) does not have "Gain" control, and the chart requires x2 gain. So I'm kinda projecting half way down, which obviously can't be good for precision.

Yes, SI2K has a default .look that may be close to reality in most situations, but I need to be able to do this myself and so far no dice.

Maybe I need better tools in terms of color correction/vectorscope plugin in AfterEffects...

[Peter Moretti]

Alex, most CC tools have some form of gain control. It may not be displayed by default when you're looking at the vectorscope but you still might have. Usually it's part of a group called Lift, Gamma, Gain. That said, you are running a very old version of Color Finesse, but I still think you probably have it. Gain is one of the most fundamental CC tools.

[Alex Raskin]

Yes CF has gain of course.

It's Vectorscope in it that does not. If you are familiar w DCS charts, they require Vectorscope (not color controls) to have gain x2, and only then the colors are supposed to fit in the boxes.

[Peter Moretti]

Alex,

Okay, now I understand your ? better, sorry. Yes that's correct, you have to use a vectorscope that can add 2X display gain to align the chart.

I know DVRack had this feature, but it is no longer made. There may be some other software only solutions, but I'm not sure of them. I'll yet you know if discover anything.

Good luck.

[Perrone Ford]

Originally Posted by Alex Raskin

Thanks Peter, this is very helpful, I will try to post a Vscope screenshot later today.

The problem might be that my software vectorscope (Synthetic Aperture's Color Finesse 1.5.7 for AE 7) does not have "Gain" control, and the chart requires x2 gain. So I'm kinda projecting half way down, which obviously can't be good for precision.

Yes, SI2K has a default .look that may be close to reality in most situations, but I need to be able to do this myself and so far no dice.

Maybe I need better tools in terms of color correction/vectorscope plugin in AfterEffects...

Alex,

Forgive me, I have not worked with Cineform RAW much. I have worked with REDCode some. If Cineform RAW is similar, you've got to define a color space. There should be a LUT (Look Up Table) selection for you to do this. If so, this will bring your colors more inline with what you're used to. And from there you can tweak.

Are you using a LUT when you record? You should be doing that, and your signal out of the camera should be painting that chart onto the proper places in the vectorscope on set. Essentially, if you intend to deliver to REC709 then that is what you'd set as a LUT in the camera, shoot the chart, tweak the camera so that all colors faithfully hit their respective tick marks in the scope, and then record to RAW. In post, when that same LUT is applied to the RAW footage you captured, the colors should come back to EXACTLY where they were on set.

I know this information is very generic and I apologize for that, but setting up a camera to a chart should be pretty similar regardless of the camera. The RAW cams (SI2K, RED, Arri) add a twist to that procedure with their LUTs, but the basics should still hold.

If this information is totally off, hopefully someone can correct it today, but to the best of my knowledge, this is how it should work.

[Peter Moretti]

Perrone, the information you've provided is correct... but the issue is with how DSC Labs constructs their CamAlign charts. The colors are muted, not heavily saturated like you'd see on a 100% or even 75% SMPTE test pattern.

So to get them to display properly, you need to have a *vectorscope* that can add x2 gain to its display. You don't/should not accomplish this by adding gain/saturation/brightness using the NLE's CC tools.

[Bob Currier]

Sorry this reply is so late, it took forever to get "approved" so I could post.

This may or may not help you, but the new version of Color Finesse (v3) included with AE CS5 does have a gain option on the vectorscope display, specifically added at the request of DSC and Gamma & Density chart users.

Right click on the vectorscope and choose the gain factor you want.

Bob Currier
Synthetic Aperture