Describe shadows, mid-tone, and highlights in terms of the tonal scale from 0 to 255 in an RGB Photo.?

Those terms aren't defined in the context of bit depth, they were referred in the old Zone System, where for a specific image zones of different tonality that fall precisely in known boundaries existed.


For example a midtone falls on Zone V in that system.





You could nevertheless define midtones with their RGB values and then consider everything with lower values shadows and higher values highlights, although shadows and highlights are more subjective terms in an image.





Many photographers consider a wide range of tones as midtones. But strictly speaking there would be only singular values for a midtone, i.e. that could be the definition for midtone and would have RGB Values of 128-128-128. Of course the same goes for individual colors (0-128-0 for instance).





But we often see grey cards of say 18% or similar.


18% is about the middle of a logarithmic scale going from zero to 100%.





Zone system is an exponential system, sensors or printers may act linearly, so you have to define your midtones in respect to the device used and the useful tonal range it can record or output.





For example, most camera meters are tuned at 18% grey, so if you wanted to define ';that midtone'; with RGB values that would be 110-110-110 and so on...Describe shadows, mid-tone, and highlights in terms of the tonal scale from 0 to 255 in an RGB Photo.?
Actually, middle gray is not half of the tonal range but at a point 1/5th of the way from full black (18% of 100). That is a perceptual determination and is the basis of metering.





Since pure 'titanium' white would be represented by the CMY scale as not applying tonality to the printing surface or represented in the RGB scale on a basis of light balance generating white from percentages of RGB inputs on monitors, a representative gray would not fall within the parameters of 255/2 in the color spectrum but rather as a relative output of light meeting the 18% scale of grayscale metering.





This is not to say that Kelvin meters (color) do not utilize 18% technologies but they do use as much as 16 million representative images as basis for determining correct exposure so to put Kelvin meters in the same classification as standard meters is profound at best.





Describe shadows, mid-tone, and highlights in terms of the tonal scale from 0 to 255 in an RGB Photo.?
0-85, 85-170, 170-255





The RGB scale is linear. The important part is knowing that the scale is linear, 255/2 is middle gray, 255 is white, 0 is black.
Black bits, grey bits, white bits.





Homework assignment?