How to take a Reference Shot of a ColorChart

The image file of the ColorChart is the basis for your profile. A wrong camera setting, software setting, exposure or simply reflections should result in a profile that does not render your images correctly.

So please have a look at this tutorial!

This is how an image of a ColorChart should look like.

The ideal for the photographing of a ColorChart exists if no artifacts and no reflections appear on the ColorChart. There should also not be any attenuation from the right to the left or from the top to the bottom. In the same sense, mixed light is not optimal and it is much better if the ColorChart is photographed filling the format and as straight as possible in the main light.

• Covered Areas on Chart
  Please take care, that there are no covered areas on the ColorChart.
• Underexposed
  This image of the ColorChart is also underexposed.
  The «correct» exposure setting depends on the task you want to use the ICC profile for.

Reproduction
To get an almost 1:1 reproduction, you have to take care that both, the ColorChart and the coherent objects you want to reproduce, are captured with the same exposure and neither the highlights nor the shadows clip.
Real World Images
The ColorChart should be exposed correctly, ignoring the surroundings. A correctly exposed ColorChart has average values between RGB 235 and RGB 245 on the white patches. This avoids highlight clipping within the images of your shooting.

Reflections on Chart

Please take care, that there are no reflections on the ColorChart.
This would result in an ICC profile, that renders the colors completely wrong!

We know, that this is sometimes hard to do! 

Too distorted 

The distortion in the ColorChart, if it is placed diagonally, is significantly stronger for short focal distances than for long focal distances. Up to a certain angle, the software can identify the fields in spite of the distortion in the photo of the ColorChart and generate a profile from this. However, this certainly has its limits.

As far as the photographing of the ColorChart is concerned, it is important to not become fixed on the photographing position for the picture. If it is too time consuming or not even possible to place the ColorChart in an optimal position in the shot design, there is nothing preventing changing the photographing position. The goal should be to photograph the ColorChart when it is well illuminated and has little perspective distortion in the main light and to generate a qualitatively precise profile from this. 

Mixed Lights

In mixed light situations, you must position the ColorChart under just one of the light sources. If two different light sources are shining on the ColorChart proportionally then no useful profiles can be generated.

Attenuation/Shadows on Chart

If the brightness of the ColorChart varies too much from the right to the left or from the top to the bottom then a qualitatively good profile cannot be generated.

Artifacts

Artifacts can arise for different reasons. Some are listed below:

• too high jpeg compression.
• wrong or bad interpolation during developing from RAW to tif/jpg.
• immoderate sharpening.

In most cases those artifacts are recognized by our True Color Technology.
If artifacts are detected, no profile will be generated.