Calibrating an alternative process shouldn't cost anything to get started. Calibration Flow offers a permanent free mode that opens the entire calibration workflow — chart, patch measurement, curve generation,

.acv

export — with no paywall on the core functions. The only entry point is a free registration through

picturale.app

(Google SSO or another method).

Free mode exists so you can calibrate your first prints with no commitment, check that the tool meets your process, and decide on an informed basis whether you want to move to Pro mode for the extended quotas.

#What happens

You open

app.calibrationflow.com

in any browser, or you launch the iOS app. The

picturale.app

hub redirects you to the registration page if you don't have an account yet. Registration in two clicks with your Google account (other SSO methods available). Once signed in, you come back to the app automatically, in free mode.

You can do real calibrations from the first second: import a chart scan, measure the patches, generate a curve, export the

.acv

for Photoshop or Lightroom. Cloud storage is on by default (300 MB) — your curves, presets and scans appear automatically on every device signed in to the same Picturale account.

#Free-mode quotas

Item	Quota
Saved curves	3 max
Presets	Unlimited
Source HD scans	10 max
Generated images (negative, positive, CMYK, tonal)	Unlimited
Total cloud storage	300 MB

When a quota nears 80%, a discreet notification warns you. At 100%, the app asks you to delete existing items or move to Pro mode to extend the quotas. Your data is never lost — it stays accessible read-only until you make room.

#What you can do

Calibrate every supported process (cyanotype, Aquaprint, carbon, platinum print, Van Dyke, bromoil, gumoil, resinotype, printer calibration, and others).
Import images (JPG, PNG, HEIC, TIFF, RAW depending on platform).
Measure the patches with the Smart Analyzer (automatic detection).
Generate the 25-point correction curve with the LOWESS + PCHIP algorithm.
Export to standard
```
.acv
```
compatible with Photoshop CS6+ and Lightroom Classic.
Sync your curves, presets and scans across every device you're signed in to.

#What free mode doesn't unlock

Custom chart creation — reserved for Pro mode.
Color Venn (CMYK preview for four-color) — reserved for Pro mode.
Advanced export options — reserved for Pro mode.
Extended quotas (unlimited curves, unlimited presets, 5 GB) — reserved for Pro mode.

If you need these functions, see Pro subscription or Luminograph code (1 year of Pro included with the purchase of a Luminograph from Vision Picturale).

#Why mandatory registration

Before 28 May 2026, Calibration Flow offered a web demo mode with no registration for 30 days. That mode was replaced by free mode with registration for three reasons:

Cloud backup by default. With an account, your curves and presets are synced to the cloud automatically. You find your work again if you change device, if your browser loses its local data, if you reinstall the app. Without an account, that was impossible.

More generous quotas than a time-limited demo. Free mode doesn't expire. You can use it indefinitely for your occasional calibrations. That's more respectful than a 30-day countdown.

Healthy product acquisition. Free registration via Google SSO takes two clicks. No credit card asked, no long form. It's simpler than the previous demo mode, which required a delicate switch to the subscription at expiry.

#Worth keeping in mind

Item	Value
Cost	Free, unlimited in time
Registration	Required (Google SSO via picturale.app)
Credit card	Not asked
Core functions	Full workflow, `.acv` export, multi-device cloud sync
Quotas	3 curves, unlimited presets, 10 HD scans, unlimited images, 300 MB
To go further	Pro subscription €9.90/month or Luminograph code (1 year of Pro included)

#The test

Open

app.calibrationflow.com

in a fresh private browsing window. The app should redirect you to

picturale.app

for registration. Sign up with a Google account (or another available SSO method). You come back to the app automatically, in free mode. Check that you can import an image, run an analysis, export an

.acv

— all the core actions should work. Sign in on another device with the same account: your data should appear automatically.