I haven't bought a professional SLR camera to take pictures of traditional oil painting, but I have a theory of a color value chart I could create with the particular camera I'll buy.
If I paint out all my tube colors and take a picture of it with the camera, I can then put the picture in Painter, use the picker to choose those colors and determine the values. Digitally picking and painting out all the colors from the picture, I can then make the chart below. The point would be, I can determine exactly what values the camera see's. In theory there should be little rework of colors and values in photoshop/painter when I take a picture with the SLR camera.
I first started making the chart to really try to figure out where exactly the values of my particular paints were located in value. A lot of the colors are hard to determine the values, for example 27% (does it belong in the 2 value range or the 3?). (note:*For this particular chart I used a scanner.*)
Does this sound like a legitimate way of determining the values of paint colors?