Blackmagic Forum

Has anyone shot what i believe is called a "Chip Chart" with the Ursa mini g2? I need this to neutralize the color response of the camera in resolve. This is the only way I know how to do this. The only charts I can find (With grey slices going from pure black to pure white) are over a thousand dollars. If anyone has any advice on a better way to neutralize the camera's colors in a more "Scientific" way before designing a look, I'm all ears.

Or....is there perhaps a LUT available for this? I cannot be the only person who wants a neutral color response free of casts. Why would casts be built into the cameras color responses?

This is far cheaper: https://calibrite.com/product/colorchec ... t-video-2/

And then, I have no problems at all getting the UMP to neutral, there are no color casts built into our camera. Either yours is broken or you are using the wrong lights.

I use a Minolta color meter when shooting. And I've got the DSC Labs smaller chip charts. It takes only slight adjustments to neutralize the image.

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samueladammartin wrote:Has anyone shot what i believe is called a "Chip Chart" with the Ursa mini g2? I need this to neutralize the color response of the camera in resolve. This is the only way I know how to do this. The only charts I can find (With grey slices going from pure black to pure white) are over a thousand dollars. If anyone has any advice on a better way to neutralize the camera's colors in a more "Scientific" way before designing a look, I'm all ears.

Or....is there perhaps a LUT available for this? I cannot be the only person who wants a neutral color response free of casts. Why would casts be built into the cameras color responses?

That's not going to work the way you think it will.
The color response of the chip chart is highly dependent on the light used to lit it.
Sun light will give a different response than artificial light. It will also depend on the time of day and sky conditions how it will look like. Depending on the position of the sun the light gets filtered differently through the atmosphere. Clouds or no clouds will have an impact on light spill, as does vegetation and the light reflected from it.

Artificial light will have a different spectrum with some parts missing. This can also lead to color differences on a chip chart.

If you want to calibrate, you will need the exact same light source for the chip chart as will be used later on set. And you will have to create different neutralizing LUTs for each source.

And then there are still not enough color patches on charts to reference all color data points.

The correct way would be to shoot color charts on set and use those then to neutralize.

Thank you for the responses! Much appreciated on my first post here.

Uli Plank wrote:This is far cheaper: https://calibrite.com/product/colorchec ... t-video-2/

And then, I have no problems at all getting the UMP to neutral, there are no color casts built into our camera. Either yours is broken or you are using the wrong lights.

I suppose maybe color cast is not what I'm seeing but rather the colors with standard display transforms from Blackmagic are yielding unnatural (To my eye) results.

Robert Niessner wrote:

samueladammartin wrote:Has anyone shot what i believe is called a "Chip Chart" with the Ursa mini g2? I need this to neutralize the color response of the camera in resolve. This is the only way I know how to do this. The only charts I can find (With grey slices going from pure black to pure white) are over a thousand dollars. If anyone has any advice on a better way to neutralize the camera's colors in a more "Scientific" way before designing a look, I'm all ears.

Or....is there perhaps a LUT available for this? I cannot be the only person who wants a neutral color response free of casts. Why would casts be built into the cameras color responses?

That's not going to work the way you think it will.
The color response of the chip chart is highly dependent on the light used to lit it.
Sun light will give a different response than artificial light. It will also depend on the time of day and sky conditions how it will look like. Depending on the position of the sun the light gets filtered differently through the atmosphere. Clouds or no clouds will have an impact on light spill, as does vegetation and the light reflected from it.

Artificial light will have a different spectrum with some parts missing. This can also lead to color differences on a chip chart.

If you want to calibrate, you will need the exact same light source for the chip chart as will be used later on set. And you will have to create different neutralizing LUTs for each source.

And then there are still not enough color patches on charts to reference all color data points.

The correct way would be to shoot color charts on set and use those then to neutralize.

A color chart does seem like the way o go for me to get a neutral color balance. Thanks again for the help everyone.

samueladammartin wrote:I suppose maybe color cast is not what I'm seeing but rather the colors with standard display transforms from Blackmagic are yielding unnatural (To my eye) results.

No camera in the world sees all colors exactly like you perceive them, please read about metamerism.
Natural light is still the best, but it changes massively over the day, with humidity in the air, and your elevation over sea level. That's what we have WB for. Tungsten is second best, but it generates more heat than light.

Modern lamps, based on fluorescence or LED, are very bad when they are cheap ones for general use, like the ones in parking areas. Sodium vapour lamps, which are used a lot these days for traffic areas, even have only one color out of the whole spectrum.

If you want practicals in your scene, check the carefully and change if needed. Only use those made for filming with a good color rendition value and switch off the rest. It can be very difficult to correct for color shifts caused by light sources which don't emit the full spectrum.

P.S. Don't blame your camera, BM's color science is one of the best.

Robert Niessner wrote:
The correct way would be to shoot color charts on set and use those then to neutralize.

This!

Every time the light source changes for a take, I ask to shoot a color chart at the preface of the take on set and then neutralize them in DVR Studio. I do that for the URSA Mini Pro G2 as well as the Pocket 6K.