Standardized FIlm 31 Step Tablet by Precision Digital Negatives

The PDN 31-Step Tablet (Designed by Mark I. Nelson)

Precision matters. Achieve superior evaluation and linearization with 1/3-stop precision. The PDN 31-Step Tablet is the standard for digital negative calibration, designed specifically to address the limitations of traditional sensitivity guides.

The Standardize Step Tablet is the Universal Yardstick for evaluation and comparison of calibrations, it allows you to communicate your results accurately with other photographers.  

This is a physical film Step Tablet on silver gelatin film.  It is NOT an inkjet tonal palette.

It is the Most Valuable and the Cheapest item in your array of darkroom equipment. (If you graph the print densities resulting from printing the standardized step tablet, you will have defined your process H&D curve.)

 A Simple Tool Tells The Big Story

• Determine The Standard Printing Time of Your Process
• Determine the Exposure Scale of Your Process
• Determine DMax and DMin of Your Process
• Determine the Density Requirements of Your Negatives/Positives
• Compare and Evaluate Chemistry Ratio Adjustments
• Compare and Evaluate the Huge Impact Moisture Content has on Exposure Scale
• Compare and Evaluate Papers
• Compare and Evaluate Other Workflow Variables

 Why the PDN 31-Step Tablet? While many standard tablets use Log .15 Density (1/2-stop) increments, this custom tablet refines the scale to Log .10 Density (1/3 stop). This tighter spacing provides 50% more data points for your linearization software, resulting in smoother gradients and more accurate profiles.

 Key Features & Usability: We designed this tablet with practical darkroom use in mind:

• Reversed Numbers: Numbers are printed in reverse on the film, so they read correctly (emulsion side down) on your final print.
• Visual Clarity: Features black & white edges for improved visual evaluation and tick marks to clearly indicate step borders.
• Easier Handling: Wide steps allow for easier "lapping" of the substrate, and the step sizes are optimized for accurate densitometer readings.
• Versatile: Works perfectly for Platinum/Palladium, Cyanotype, and Positive Processes such as Photopolymer Gravure & Copper Plate Photogravure.

Technical Specifications:

• Precision: Each step is Log .10 Density (1/3 Stop).
• Exposure Calculation: Three Steps = 1 Stop Exposure.
• Range: Approx. 10 Stops of Density/Exposure (Step #1 = Log .05 to Step #31 = Log 3.05).
• Dimensions: 1 in. x 7 in. (Strip format).
• Calculation Guide: Simply divide the Step Number by .1 to determine the Density or Exposure of that step.

Authenticity:

• Designed by: Mark I. Nelson
• Manufactured by: Stouffer Industries (Custom produced for Precision Digital Negatives, Inc.)