In the tutorial Using curves to correct color, on page 103. The values given in the book, do not match the values I actually measure. Is this a typo in the book, or is this evidence that my monitor calibration or color profile are not correct?

Or is this intended to show how far off the color is from original?

(sorry, its hard being a bit daft and this chapter has been very slow going for me, 6 aspirin so far :))

As far as the exercise goes, I wouldn't worry about it! The point is to demonstrate colour correction using curves -- just write down the RGB values you get, do the math, and use your values.

FWIW, i've just checked the values I see, and for me:
* the 50% values are the same
* the 25% values are each 1 less
* the 75% Red value is 55; the others are the same

Cheers,
Paul.

Thanks Paul,

I finally got the point of the tutorial, its just that I was thinking I was doing it wrong or had something wrong with my machine. I am learning to take the essence of the lessons instead of the letter of the lessons.

I am a bit greedy and keep moving on in the book, so will have to double back and do it all again step by step with a few of my own images to really catch on.

Thanks again for your help!