FAQ
How do I run PPRC without using the command line?
Once installed, it’s a single command. On macOS you can install a Finder Quick Action to get a right-click “Process with PPRC” option, no terminal needed.
Why might I want to use a .raw workflow with my Pakon, why not just save from PSI?
PSI produces decent images and some people prefer using them as-is. But PSI works with more data internally and then discards much of it when saving to 8-bit. The images are also heavily processed with Kodak’s automatic adjustments. PPRC preserves the full sensor data and gives you a neutral starting point with more dynamic range and detail to work with. See the 8-bit vs 16-bit Pakon comparison.
Why use TLXClientDemo instead of PSI for raw files?
PSI can only export 8-bit files, even when exporting “raw” TIFFs. This limitation shows up most often as visible banding in the highlights. TLXClientDemo’s planar raw output preserves the full sensor data. See the highlight issue →
Does PPRC replace the Pakon F135+ scanning software?
No. PPRC does not run the scanner. You still use PSI or TLXClientDemo to scan and save files.
After scanning, use PPRC to turn the saved raw files into editable 16-bit TIFFs with maximum data.
Can’t I just open the planar raw files in Photoshop?
You can, but you’ll have to manually specify the image dimensions, channel count, bit-depth, and header offset each time, then save out to a TIFF. PPRC detects all of this automatically (from file headers or known file sizes) and processes an entire directory at once.
Can I use my own inversion tool?
Yes: run with --mode raw to get linear 16-bit TIFFs without orange mask removal, ready for Negative Lab Pro, ColorPerfect, Vuescan, or any other tool. That said, it’s worth trying PPRC’s own inversion first, especially if you haven’t tested it since the 1.0 ground-up rewrite.
But doesn’t using PPRC lose the Kodak color science?
Yes. PPRC does not try to preserve the baked-in Pakon look. Whether that is good or bad depends on what you want from the scan.
Taste is subjective, and plenty of people like the default Pakon look. But much of that look comes from the original Pakon software’s minilab-style adjustments: automatic color, contrast, and density decisions designed for good glossy 4x6 prints. That is not always the best starting point for a modern editing workflow.
The original Pakon software can also use a film-type lookup table keyed from the film’s latent image DX code printed at the edge of the film. That table was built for the films the Pakon software knew about at the time, last updated in 2006. It was not updated for any current film stocks, so with almost all film now the system falls back to a generic approach for that part of the processing anyway.
PPRC takes a different approach: it derives a neutral profile from the roll’s own image data. The goal is not to imitate a finished lab look. It is to give you a clean, data-rich starting point that you can tune in your editing workflow.
Why is the output so flat?
This is by design. PPRC’s goal is to preserve as much data as possible from the raw file, so the default output is intentionally neutral and flat, with plenty of headroom to edit, rather than a punchy, finished look. If you want something closer to a final image straight out of PPRC, try a stronger contrast stretch with --clip 0.1.
How does the color inversion work?
PPRC comes with its own inversion pipeline tuned for Pakon raw scans. All images in a batch are analyzed together to compute a shared color profile. This produces more consistent results across a roll than analyzing each frame individually.
For best results, process a whole roll together when possible instead of splitting it into small batches. The shared analysis and outlier-frame rejection both work better with more context from the rest of the roll.
During analysis, the very brightest and darkest pixels within each frame are ignored so that dust spots or specular highlights don’t skew the profile. Outlier frames (e.g. backlit shots with very different color characteristics) are automatically excluded from the shared profile so they don’t throw off the rest of the roll.
You can tune the inversion behavior with CLI options or save your preferences in a global config file.
PPRC 1.0+ uses a purpose-built inversion engine to handle color analysis and orange mask removal. Prior to version 1.0 (released July 2026), PPRC used the negfix8 shell script (which relied on ImageMagick) for inversion. That approach was slow (a 37-frame roll took around 2.5 minutes), produced less consistent results due to per-image analysis only, was easily skewed by large dust spots, and required ImageMagick to be installed separately. The current pipeline is fully self-contained, around 50x faster for the same workload, and produces significantly more consistent results thanks to whole-roll analysis and automatic outlier frame rejection.