Matrix adjustment/paint for F350/DSR450 at DVinfo.net

Peter Newsom · March 7th, 2007, 07:57 AM

Can anybody direct me to resources that would help me understand how to go about creating a "look" in camera. I don't have any experience in this area, but would like to get a grip on the fundamentals of colour adjustment.

Thanks for any help.

Peter

Greg Boston · March 7th, 2007, 08:55 AM

The basic concept behind the user matrix is that you have 2 listings for each of the 3 primary colors.

The adjustments allow you to 'spill' a certain amount of color information from one channel into the other 2. So IOW, Red can be added to Blue or Green, Green can be added to Red or Blue, and Blue can be added to Red or Green.

Obviously, you don't 'mix' color onto itself, but you can adjust the gain of each color channel to enhance or decrease that primary color's saturation.

All of this is best done with a waveform/vectorscope monitor.

-gb-

Jeff Regan · March 7th, 2007, 10:21 AM

I would add that using a MacBeth color chart is helpful. I have done scene files
in my DSR-450 that emulate the look of a Panasonic SDX 900 and DVX 100(which
required the Multi-Matrix additionally as the Matrix didn't have enough range for
the amount of green needed).

I shoot the MacBeth chart with the camera I want to emulate, put an overlay on a
vectorscope and use a marker to plot the dots on the scope. Then I use the
matrix in the other camera, which is in the same exact position as the first camera
to emulate those color points.

To do a camera emulation you also have to match gamma curves, detail, knee,
flares, but a digital camera with the amount of control that if found in a DSR-450
can really get very close to the colorimetry of another brand camera, or a color
palette that serves your vision of a project.

Jeff Regan
Shooting Star Video
www.ssv.com

Peter Newsom · March 7th, 2007, 03:01 PM

Thanks guys that is very helpful.

If you want to achieve a certain look by adjusting on location until it looks the way you want it on a monitor that you know, do you still need the vector scope or can you "eye ball it"?

Are there any pitfalls to be aware of?

Simon Wyndham · March 7th, 2007, 03:53 PM

It is best not to eyeball. Such camera setups need to be done under controlled conditions using a known quantity by which to judge, such as the MacBeth chart, or more ideally something like a DSC Labs ChromaDuMonde or an SMPTE or EBU chart.

I've planned some setups that I think people will like but it will take me a few weeks to release them.

Jeff Regan · March 7th, 2007, 08:36 PM

Adjusting matrix on location, without a reference, is not for the timid. Much
easier to use R and B gamma or gains to warm or cool an image. Matrix, with
its two adjustments per channel, is not so straight forward. The minimum you
should have on location would be a Macbeth chart and a flesh chart or real
person to look at. Tweaking the matrix is not the work of a moment and each
adjustment has an interaction that needs to be looked at on a color chart.

A good thing about most Sony cameras is that they have matrix off, preset matrix and user matrix. In order to use the latter, the preset matrix must be
on, but what's nice is that you can adjust the user matrix, then turn it off and
on to compare to the preset matrix. On newer cameras, you also have multi-matrix, which is additive to the user matrix and the ability to just change the value of a specific color and specific area of the frame.

These kind of circuits should be tested at a time when you are not on location in the middle of a production.

Jeff Regan
Shooting Star Video
www.ssv.com

March 7th, 2007, 07:57 AM	#1
Peter Newsom Regular Crew Join Date: Nov 2006 Location: Ottawa, Canada Posts: 182	Matrix adjustment/paint for F350/DSR450 Can anybody direct me to resources that would help me understand how to go about creating a "look" in camera. I don't have any experience in this area, but would like to get a grip on the fundamentals of colour adjustment. Thanks for any help. Peter

March 7th, 2007, 08:55 AM	#2
Greg Boston Wrangler Join Date: Oct 2003 Location: DFW area, TX Posts: 6,117 Images: 1	The basic concept behind the user matrix is that you have 2 listings for each of the 3 primary colors. The adjustments allow you to 'spill' a certain amount of color information from one channel into the other 2. So IOW, Red can be added to Blue or Green, Green can be added to Red or Blue, and Blue can be added to Red or Green. Obviously, you don't 'mix' color onto itself, but you can adjust the gain of each color channel to enhance or decrease that primary color's saturation. All of this is best done with a waveform/vectorscope monitor. -gb-

March 7th, 2007, 10:21 AM	#3
Jeff Regan Regular Crew Join Date: Mar 2007 Location: Foster City, California Posts: 192	I would add that using a MacBeth color chart is helpful. I have done scene files in my DSR-450 that emulate the look of a Panasonic SDX 900 and DVX 100(which required the Multi-Matrix additionally as the Matrix didn't have enough range for the amount of green needed). I shoot the MacBeth chart with the camera I want to emulate, put an overlay on a vectorscope and use a marker to plot the dots on the scope. Then I use the matrix in the other camera, which is in the same exact position as the first camera to emulate those color points. To do a camera emulation you also have to match gamma curves, detail, knee, flares, but a digital camera with the amount of control that if found in a DSR-450 can really get very close to the colorimetry of another brand camera, or a color palette that serves your vision of a project. Jeff Regan Shooting Star Video www.ssv.com

March 7th, 2007, 03:01 PM	#4
Peter Newsom Regular Crew Join Date: Nov 2006 Location: Ottawa, Canada Posts: 182	Thanks guys that is very helpful. If you want to achieve a certain look by adjusting on location until it looks the way you want it on a monitor that you know, do you still need the vector scope or can you "eye ball it"? Are there any pitfalls to be aware of?

March 7th, 2007, 03:53 PM	#5
Simon Wyndham Trustee Join Date: Dec 2003 Location: Malvern UK Posts: 1,931	It is best not to eyeball. Such camera setups need to be done under controlled conditions using a known quantity by which to judge, such as the MacBeth chart, or more ideally something like a DSC Labs ChromaDuMonde or an SMPTE or EBU chart. I've planned some setups that I think people will like but it will take me a few weeks to release them.

March 7th, 2007, 08:36 PM	#6
Jeff Regan Regular Crew Join Date: Mar 2007 Location: Foster City, California Posts: 192	Adjusting matrix on location, without a reference, is not for the timid. Much easier to use R and B gamma or gains to warm or cool an image. Matrix, with its two adjustments per channel, is not so straight forward. The minimum you should have on location would be a Macbeth chart and a flesh chart or real person to look at. Tweaking the matrix is not the work of a moment and each adjustment has an interaction that needs to be looked at on a color chart. A good thing about most Sony cameras is that they have matrix off, preset matrix and user matrix. In order to use the latter, the preset matrix must be on, but what's nice is that you can adjust the user matrix, then turn it off and on to compare to the preset matrix. On newer cameras, you also have multi-matrix, which is additive to the user matrix and the ability to just change the value of a specific color and specific area of the frame. These kind of circuits should be tested at a time when you are not on location in the middle of a production. Jeff Regan Shooting Star Video www.ssv.com