One of the pluses of shooting digitally is seeing your results instantly. One of digital photography’s most valuable feedback tools is a histogram.
What is a histogram? A histogram is a graph that shows the balance and placement of pixels in an image.
The graph features 256 vertical bars representing the images luminosity numbered from 0, pure black on the left to 255, pure white on the right representing the 256 levels of grayscale that the human eye is able to recognize.
The taller the bar the more pixels there are in the image at that level. Click on Graph for more information.
First open Photoshop, go to the “Edit” menu and scroll down and click on “Color Settings”
In the Working Spaces area under the RGB heading select sRGB IEC61966-2.1 and under the Gray heading select Gray Gamma 1.8.
Under the Color Management Polices heading in the RGB section choose “Preserve Embedded Profiles” and check both the “Profile Mismatches” as well as “Missing Profiles” boxes. Finally under the “Conversion Options” heading in the “Intent” area select “Perceptual” and uncheck all the other boxes. You may now close the Color Settings window by clicking the OK button.