Creating Digital Negatives in Lightroom Classic
Yes. I’d document the normal B&W proof as an explicit step before negative production. It separates an image-editing problem from a negative/process-calibration problem, which will be extremely useful when returning to the workflow months later.
Here’s a version designed specifically as a “future Terry forgot everything” reference.
Lightroom Digital Negative Workflow
Epson SureColor P800 • Pictorico OHP Film • Alternative Process Printing
Purpose
This workflow creates calibrated digital negatives entirely within Lightroom Classic, avoiding the need to move photographs into Photoshop solely for inversion and curve application.
The Lightroom tone curve performs two jobs:
It inverts the image into a negative.
It applies the process-specific correction curve required for the alternative photographic process.
The digital negative is printed directly from Lightroom’s Print module using the Epson P800.
A step wedge derived from the Dan Burkholder Photoshop digital-negative template is included alongside the photograph whenever useful. This provides a permanent process reference on the same sheet of film as the image negative.
1. Prepare the Photograph
Complete the photographic interpretation of the image in Lightroom before thinking about the digital negative.
Adjust the image normally as a positive photograph.
Pay particular attention to:
Overall tonal distribution
Highlight separation
Shadow detail
Midtone relationships
Local contrast
Whether important areas are approaching pure black or pure white
Do not attempt to compensate at this stage for cyanotype, platinum/palladium, or another printing process.
The objective is to create the photograph you actually want.
2. Make a Normal Black-and-White Proof
Before creating the digital negative, make a conventional positive black-and-white proof print.
This is an important diagnostic step.
The proof establishes that the Lightroom image itself has an appropriate tonal range before the alternative-process workflow is introduced.
Examine the proof for:
Blocked shadows
Empty or excessively bright highlights
Weak midtone separation
Excessive contrast
Insufficient contrast
Distracting local tonal relationships
Areas that need dodging, burning, or other local adjustments
If the normal B&W proof does not look right, return to the Lightroom image and correct it.
Do not attempt to solve an image-editing problem by modifying the digital-negative calibration curve.
The proof should represent a satisfactory photographic interpretation before proceeding.
3. Apply the Process-Specific Digital Negative Preset
Once the positive image is satisfactory, apply the appropriate Lightroom digital-negative preset.
For the established cyanotype workflow, the current baseline is:
P800 Cyanotype Sepia Darkest Corrected v4
This curve already contains the inversion.
Applying the preset therefore changes the positive photograph into the corrected negative required for printing.
Do not invert the photograph separately.
Do not export an inverted TIFF simply to make the negative.
The inversion and process correction are both handled by the Lightroom tone curve.
4. Remember That Curve Corrections Work Backwards
This is one of the most important aspects of the workflow.
Because the Lightroom curve contains the negative inversion, adjustments can initially feel backwards.
When evaluating the final alternative-process print:
If an area of the print needs to become darker:
The corresponding area of the digital negative generally needs to become lighter / more transparent, allowing more UV exposure.
If an area of the print needs to become lighter:
The corresponding area of the digital negative generally needs to become darker / more opaque, reducing UV exposure.
Always think through the negative-positive relationship before changing the calibration curve.
5. Step Wedge
The calibration step wedge originated with the Dan Burkholder Photoshop digital-negative template.
The step wedge was saved from the Photoshop template as a TIFF.
It is imported into Lightroom and can be placed beside the photograph in the Print module as a second image.
This allows the image negative and reference step wedge to be printed simultaneously on the same sheet of Pictorico film.
The step wedge provides a useful record of how the process is behaving and can help distinguish between:
Image-specific problems
Curve problems
Exposure changes
Chemistry changes
Coating inconsistencies
Processing changes
When performing calibration work, keep the step wedge in the workflow.
6. Lightroom Print Module
Create the negative directly from Lightroom’s Print module.
Place the photograph and, when desired, the Burkholder step-wedge TIFF on the print layout.
The photograph should already have the process-specific digital-negative preset applied.
The step wedge serves as the process reference.
Print directly from Lightroom rather than exporting the negative and reopening it elsewhere.
This keeps the workflow short and minimizes unnecessary variables.
7. Epson P800 Printing
Print the negative on Pictorico OHP transparency film using the Epson SureColor P800.
Maintain the established printer settings consistently.
The current workflow uses the Epson sepia/brown ink treatment with:
Tone: Darkest
Consistency is more important than continually searching for theoretically better printer settings.
Once a curve has been calibrated for a particular combination of:
Printer
Ink
Film
Driver settings
Alternative process
Paper
Exposure
Chemistry
Processing
those variables form a single printing system.
Changing one may affect the calibration.
8. Make the Alternative-Process Print
Expose and process the negative using the established procedure for the process being tested.
For meaningful curve evaluation, keep the physical printing procedure as consistent as possible:
Paper
Coating volume
Coating technique
Coated area
Drying
Humidity
Exposure
Chemistry
Development
Clearing/washing
Final drying
A poorly coated print should not be used as the basis for modifying the digital-negative curve.
First determine whether the problem is photographic, digital, or physical.
9. Evaluate the Print
Evaluate a fully processed and preferably dry print.
Ask three separate questions.
A. Is the original photograph right?
Compare against the normal B&W proof.
If the underlying tonal interpretation is wrong, correct the photograph rather than the process curve.
B. Is the physical print right?
Look for:
Uneven coating
Streaking
Pooling
Insufficient sensitizer
Excess sensitizer
Processing marks
Paper problems
Exposure inconsistencies
If these are present, correct the physical process before recalibrating the curve.
C. Is the calibration right?
Only after A and B have been eliminated should the digital-negative curve become the primary suspect.
Look for systematic tonal problems such as:
Consistently blocked shadows
Compressed highlights
Poor highlight separation
Poor shadow separation
Midtone compression
An overall tonal shift that appears consistently across well-made prints
10. Adjusting the Curve
Do not modify a working curve because of a single questionable print.
A curve adjustment should be based on repeatable tonal behavior visible in properly coated and processed prints.
When a change is justified:
Identify the tonal region of the final print that is incorrect.
Determine the corresponding region of the original positive image.
Remember that the Lightroom curve contains the inversion.
Determine which direction the negative density must move.
Make a small curve adjustment.
Save the result as a new preset/version.
Print another controlled test.
Compare against the previous version.
Never overwrite a successful calibration preset.
Use version numbers so it is always possible to return to a known-good curve.
11. Current Cyanotype Baseline
The established cyanotype baseline is:
P800 Cyanotype Sepia Darkest Corrected v4
The Cattails in the Snow image produced a convincing photographic result using v4 after the coating technique was improved.
This demonstrated something important:
The apparent tonal problem was substantially influenced by coating technique rather than necessarily being a curve-calibration problem.
Therefore, v4 should remain the working cyanotype baseline unless several properly coated prints reveal the same repeatable tonal deficiency.
Do not recalibrate simply because one print looks wrong.
12. Moving to Another Process
Cyanotype, platinum/palladium, Van Dyke brown, and other processes should ultimately have their own calibrated presets.
A successful curve from one process can provide a useful conceptual or experimental starting point, but it should not automatically be assumed to be correct for another process.
For a new process:
Establish consistent chemistry and coating.
Establish the standard exposure.
Make test prints.
Evaluate the step wedge.
Adjust the digital-negative curve only after the physical process is repeatable.
Save the successful calibration as a clearly named process-specific Lightroom preset.
Eventually the Lightroom preset library can contain separate calibrated negative presets such as:
P800 Cyanotype – [version]
P800 Platinum/Palladium – [version]
P800 Van Dyke – [version]
Each becomes a repeatable recipe for that particular printing process.
Quick Restart Checklist
If returning to digital negatives after several months or years, follow this order:
Open the finished positive photograph in Lightroom.
Make a normal B&W proof print.
Correct the photograph until the proof looks right.
Apply the appropriate process-specific digital-negative preset.
Open the Lightroom Print module.
Add the Burkholder step-wedge TIFF as the second image when testing or calibration is useful.
Print on Pictorico OHP film using the established P800 settings.
Coat the alternative-process paper consistently.
Expose using the established standard exposure.
Process normally.
Evaluate the physical quality of the print first.
Compare its tones with the B&W proof.
Modify the digital-negative curve only when a repeatable calibration problem has been demonstrated.
Save every successful curve revision as a new version.
Guiding Principle
Keep the variables separated.
First make sure the photograph is right.
Then make sure the physical printing process is right.
Only then adjust the digital-negative calibration.
The purpose of this Lightroom workflow is not simply convenience. It is to create a controlled system with as few moving parts as possible, making problems easier to identify and successful results easier to repeat.
I’d treat this as the master workflow document, then add small process-specific appendices for Cyanotype, Pt/Pd, and eventually Van Dyke. That way you don’t end up with three nearly identical workflows slowly drifting apart.