Confused by Matrix - please help

[Paul Cascio]

I bought a DSC Cam-align chart and want to play around with profile settings. However, I can't figure out which way the different settings (R-B, G-R, etc) effect the vectorscope readings. Forr example, say the Green chart chip is reading too yellow, or the Magenta isn't intense enough. Can someone explain this in simple terms please?

Thanks

[Clark Peters]

Go to post #393 (page 27) in the Picture Profile Recipes thread. Omar Idris explained it about as simply as possible. (Simple being a relative term.)

Pete

[Paul Cascio]

Clark, that post did nothing to address my questions.

[Clark Peters]

I didn't think it probably would. I have had the same question, but never found a simple answer.

The Matrix function is based in television engineering. It isn't a simple concept, so there won't be simple answers.

Unless you have a background in television engineering, making changes in the Matrix will be hit-or-miss. All the parameters are interrelated. Change one and it affects the others.

Good luck. Please let me know if you find some answers.

Pete

[Piotr Wozniacki]

One of the most comprehensible concepts of RGB color space is the so called RGB cube:

RGB color space - Wikipedia, the free encyclopedia

Read the "Intuition" paragraph...

[Paul Cascio]

Thanks Clark and Peter. I assumed that if I wanted to move the scope position of a Cyan sample, that one of the choices would rotate its position, and another would adjust the intensity level. Is that not the case?

Is there a manual or a Sony doc that explains how to use the Matrix function?

[Philippe Simon]

Have a look at this

Alister Chapman DoP, Stereographer XDCAM EX Matrix

[Philippe Simon]

Or this

YouTube - XDCAM EX Gamma Curves and Knee, what they do and which ones to use.

[Clark Peters]

Thanks Philippe. Leave it to Alister to explain what I had given up understanding.

Pete

[David Issko]

Originally Posted by Paul Cascio

I bought a DSC Cam-align chart and want to play around with profile settings.
Thanks

Paul,

I have a DSC chart. Now the first thing you will notice and read is that the colours on the chart have been purposefully set up with 'real world' desaturated colour chips. So, to properly align the dots on a vectorscope, you will need a vectorscope that you can adjust the gain.

So with your matrix on but setting at zero, you need to turn the gain up until the main colours are in or close to each box. From there you can 'play' with your matrix settings. It does not take long to see the result of adjusting one setting.

Depending on how many colours your chart has, you can then set the matrix to track the dots around the vectorscope accordingly. When finishes, return the vectorscope gain to unity and test out the camera as you may want or need to modify the colours to achieve the result you seek.

Check out DSC's website for lots of hints and tips on camera alignment setups.

Best wishes

[Andrew Stone]

David,

Curious about your feelings on which DSC Chart is best in terms of cost/benefit. I am just about to get one, and am killing myself over which one to get given how expensive the ChromaDuMonde charts are particularly when you throw in the accessories.

Big question, at present, is about the number of colors to get. Seems a lot of people settle for 12 colours and the FrontBox series but I see horror stories like the one shown in the image attachment below. If you were to buy a chart again what chart would you go for?

The Red Chart book looks good as it has 24 colors plus 4 fleshtones but concerned about the gloss lamination and the size. Do you just hold your nose and blow a fortune on the ChromaDuMonde chart or settle for someone more modest and put the savings into retirement or a bunch of lights? Your thoughts please.

[Alister Chapman]

I often use a simple color photograph to set up a non standard matrix. I have a photo that includes, sky, foliage, brightly colored cars and faces. I use this phot to set up the matrix as I can see what the changes are doing to a real world scene. Always using the same scene helps as you know what it should look like on your monitor and you can keep several copies of the photo in your kit bags.

Clearly if your going for accurate reproduction then a proper CDM chart is the best way to go, but for creating a "look" I always refer to my photo as a real world reference.

[David Issko]

Originally Posted by Andrew Stone

David,

Curious about your feelings on which DSC Chart is best in terms of cost/benefit.

Seems a lot of people settle for 12 colours and the FrontBox series

Your thoughts please.

Hi Andrew,

I have the 12 colour frontbox Professional + skintone chart. It has this on one side and a lens flange focus (back focus) chart on the other side. Yes the CDM charts are a small fortune. I found the chart that I have, very good value and although I enjoy using it for camera matrix setup, I do not place too much emphasis on the chart alone. I do check out real world images and make sure that the camera tracks colours faithfully.

Thankfully, my PMW 350 came out of the box so well set up, I really did not have to adjust the matrix terribly much.