The Logarithmic Digital Negative
TruNeg is fundamentally different to how other digital negatives are made. It eliminates the need to invert and measure a matrix of tones and the associated coating and processing problems, and does not use or require blocking colours or apply linearisation and normalisation procedures. Instead, the application calculates the true photographic negative from the inverse relationship between the positive and negative logarithms, requiring only two RGB inputs to produce a negative indistinguishable from a scanned silver gelatine negative.
The Original Image
The Logarithmic Negative
The Traditional Inverted Negative
Printing Logarithmic Negatives
Option A
Starting with what is essentially a silver gelatin negative, you can approach printing using the traditional black-and-white darkroom practice of assessing and adjusting test strips. Paper grades are replaced with an adjustment curve that lets you selectively lighten or darken the highlights, midtones, or shadows. While this approach requires some experience and expertise, it puts you in control of the printing process. Profiles available from the website make the process easier.
Option B
After establishing the exposure and negative range, using a densitometer or Stouffer Opaque Gray Scale, it takes only ten minutes to find the RGB values of ten intermediate densities specified by the program to correct the printer and process variations and make a negative that can go straight to print.
TruNeg is a stand-alone application for macOS and Windows 10/11 that creates logarithmic digital negatives.
You can download a fully functional watermarked version for testing at no cost or purchase an unwatermarked
version for US$35.00. See the Downloads page.