Hello! I am very excited to use your tool for analyzing photographs, but unfortunately the photographs I am using were taken before my involvement in the project, and leave much to be desired. Specifically, the photographs were taken under fluorescent lighting conditions. Is there any way I can use your method for creating a cone catch mapping model for our camera with the chart method, given that the lighting conditions are not sunlight? Should we take photos of the chart in the same lighting conditions, and is there any way we can figure out the illumination spectrum of our lighting conditions? We are really trying to analyze achromatic and chromatic contrast, but my understanding is that to run these analyses we need cone catch values, and to get those I need to create a cone catch mapping model. Thank you!
Not to worry – it’s pretty common to have these issues. Fluorescent lights are really “spiky”, so are very poor for colour reproduction (i.e. the colours might look quite different under natural light).
The safest bet would be to photograph the chart under the fluorescent light used for the main photos, and simply model everything under that lighting setup. You could run a test to see how the model performs under natural light if you’d like. i.e. create a cone-catch model under fluorescent light, and a second under daylight. Then use the “wrong” model, the daylight model with fluorescent chart photo, and quantify the difference. This will give you some idea of how similar the illuminant and models are for colour reproduction (though only for the chart colours). That should appease reviewers (e.g. you could say colour chart colour reproduction error was on average #%).