Question: Can i use CIELAB and D65/1- or F2 to report a/b ratio?
Answer: The Illuminant/Observer combination can have a significant affect on the results. Historically and currently all three types of Tomato tiles, USDA UCDavis, BCR400, HunterLab Tomato are all assigned in HunterLab L,a,b, for C/2. If you use CIELAB L,a,b* or any other illuminant/observer combination such as D65/10 or F2, F7, F11 then the numbers can vary greatly. I would hope that they are not just trying different illuminant/observer combinations until they get numbers that they like.
We have one customer who orders the new HunterLab Tomato tile and requests that we use CIELAB C/2 on the label, which is not the normal convention, and may cause confusion if compared to the Hunter Lab C/2 a/b ratio.