File Settings

TruNeg relies upon the inverted file value being the result of subtracting the positive value from 255. Generally the files should be set up as shown below:

• RGB Color mode, 16 bits per channel and Adobe RGB (1998)

• Grayscale can be used under certain circumstances but check that when inverted the inverted cell values are the same as the bottom row of RGB values in the illustration below. 

• TruNeg will not work properly in sRGB mode.

• Colour Management may need to be turned off, depending on the program.

Photo editing programs vary in their practices and it is impossible to give detailed instructions for every program. The image below shows the TruNeg Step Wedge with the tones numbered in the top row, the positive values in the row below the step wedge and the correct inverted value below that. Using a Color Picker check that the editing program displays the positive and inverted step wedge as notated. GIMP in particular can be difficult to set up correctly.