Support

What's the difference between Speed Point EI and Zone V EI?

Speed Point EI is calculated from the shadow toe of your H&D curve — where density first rises above base+fog by 0.1. This is the classic B+F method used in BTZS and most film datasheets. Zone V EI locates your midtone exposure by finding where density reaches 0.72D above B+F. ZoneLab reports both and recommends the more conservative of the two as your working EI.

My densitometer readings aren't being detected.

ZoneLab supports the Printalyzer UV Densitometer via USB serial. Make sure the device is plugged in before launching the app, and that macOS has granted USB access. You can also enter readings manually — click any zone field and type the value directly.

How do I compare multiple sessions?

Select up to five sessions from the session list and they'll overlay on the H&D chart simultaneously. Each session gets its own color. Hover over the chart to see an SBR arc for that exposure range. See the Session Comparison section of the User Guide for details.

Can I export my data?

Yes. Use File → Export Sessions as CSV to export all session data, or File → Export Chart as PNG (⌘⇧P) to save the current chart view as a high-resolution image. CSV exports can be reopened in any spreadsheet app.

Where is my data stored?

All data is stored locally on your Mac using Core Data. Nothing is transmitted over the network. You can find the database at:

~/Library/Containers/app.zonelab.ZoneLabApp/Data/Library/Application Support/

What macOS version is required?

ZoneLab requires macOS 14 Sonoma or later. It is a native Mac app — there is no iOS version.