Histogram?
The histogram represents a tonal range of 256, 0-255, values. Spikes on the left or right indicates a loss of detail.
Our cameras use 10 to 14 bits per color. Each color has 1024 to 16384 values of tonal range.
My question is how to change 1024 or 16384 to 256?
To get 1024 to "fit" 256 you group 4 shades to 1. 16384 to "fit" 256 you group 64 shades to 1.
It's like breaking a mile to quarter mile segments, yard, feet, inches, in...
Just like breaking down a mile into smaller units (quarters, yards, feet, inches), a histogram attempts to represent the vast range of color information (10-14 bits per color) into a much smaller number of levels (usually 256).
Mile: Represents the full range of color information captured by the sensor.
Quarter Mile: A larger division, still representing a significant portion of the overall distance.
Yard: A smaller division, providing more detail within the quarter mile.
Feet: Even smaller divisions, offering more precise measurements.
Inches: The smallest unit in this analogy, representing the limited number of levels (256) in the histogram.
This analogy highlights how the histogram, with its limited number of levels, simplifies the vast amount of color information captured by the sensor, potentially leading to a loss of fine detail.
Some time in 2019 I purchased my Nikon D5500. Later I bought 2 ebooks by Steve Perry, "Secrets To Exposure And Metering For Nikon" which I quoted below
"The Histogram Lies To RAW Shooters If you’re a RAW shooter - and you should be - there’s an important asterisk associated with all of the info we just covered. When you look at the image and histogram on the back of the camera you are NOT seeing the real RAW image – only an embedded JPEG created from the RAW file. (GASP!) Sometimes even if a histogram indicates blown highlights or solid blacks, there may still be some detail you can recover later with your RAW processing software (especially true for clipping on the left side). If you’re way under or over (highlights are especially problematic), feel free to assume the photo is going to see the inside of the virtual trash bin. Also, since the camera is generating the histogram from the embedded JPEG file, you have to consider what picture profile you’re using. A profile with more contrast will tend to show clipping before a profile with a flatter rendition, even with the same exposure. And of course RAW has more latitude than any embedded JPEG."