Step target values vs photoshop values

I have done a HW calibration on my BenQ monitor. I have profiled 3 papers for the Epson 4880 and Epson 3880 printers. I was curious as to how accurate was my HW calibration? My theory was that if I bring a 51 step or 256 step targets into Photoshop the values for each wedge should be their respective lightness value. For instance, if I’m using a 256 step target each wedge would increment by 1, ie if I’m 10 wedges from the brightest value of RGB 255 than the reading should be RGB 245. If this is correct then each wedge should increment by 1 if I’m in Photoshop with 8 bits per channel and read with the eye dropper in the center of each wedge. When I do this, I get some readings that are off by some times 2 or 3 numbers. Am I being to anal in thinking that if I have a HW calibrated monitor than the step target wedges should read their respective value.


I think I might have been measuring incorrectly. If I measure as K value for Grayscale the values are correct.

You are confusing two things. If your file is accurate then your eyedropper will read the same values even if you were using the cheapest monitor you could buy. What your HW calibrated monitor should be able to do is let you see all the individual steps without blocking up. If you want to see how well your monitor performs try this Eizo site.