The sepia tone employed in black and white photography is the result of converting the metallic silver in a photograph to a sulphide.
It not only made the photo more attractive and fashionable, but it also elongated the image's permanence. Today, sepia toning is a term for any monochromatic photo with a brownish tint to make it look old fashioned.
Although true sepia toning renders an overall brownish tint to a black and white photo, we can make it more interesting by combining the silver gray of the high and middle tones of a black and white photograph with the rich warm darks of a sepia toned image.
Click on ImageAdjustmentsDesaturate to change a color picture to gray tones.
Select the Shadows button in the Tone Balance section.
Adjust the Color Levels to give the shadows a rich warm red brown tone. Use these parameters:
Color Levels: 24 / 0 / -24
Select the Highlights button in the Tone Balance section.
Adjust the Color Levels to give the highlights a silvery gray tone. Use these parameters:
Color Levels: -24 / 0 / 24
The sepia tone in the dark areas gives an aged look while the gray values enhance the aerial perspective and add depth to the photo image.