Detection
Detection found the wrong number of steps. That is Detect Corners and Steps adopting the classifier’s reading. Set Cols / Rows / Steps by hand, then click Detect Corners instead — it finds the outline and keeps your layout. Doing it in that order is why that button leads the section. If the outline is fine and only the numbering is wrong, leave detection alone and fix the axis toggle and step-0 corner in the toolbar.
Detection failed with an alert. Choose Place corners manually in the alert, then drag the seeded quad onto the wedge — or dismiss it and Shift + ⌘ + drag a rectangle over the wedge instead. Detection struggles most with very low-contrast scans, wedges photographed at a steep angle, and images where the wedge is a small part of a large frame.
The circles are on the patches but the numbers run backwards.
That is the cell order, not the geometry. Flip the toolbar’s ↕/↔ toggle,
or pick a different step-0 corner. Step 0 is the paper-white end.
The detect buttons are greyed out. Either no image is loaded, or a detection is still running.
Measurement
One step is wildly out of line with its neighbours. Zoom in (⧉ in the zoom chip) and look at where its circle landed — dust, a coating streak, a fingerprint or a pinhole will do it. Drag the circle to clean paper; the nudge survives later corner adjustments.
Every reading looks noisy. Raise Blur a little, or increase the Radius so each patch is averaged over a wider disc. If the noise is in the series rather than the pixels, raise the Smoothing window in the Processing section instead.
The tonal range looks compressed.
Check that the print is fully dry, that the scanner had auto-exposure and
auto-levels off, and that the white reading and black reading in the
statistics panel match what you see on the print. Readings are normalized to
the wedge’s own extremes, so a clipped scan quietly costs you range at both
ends. Density range is the log figure to quote and compare between
sessions; it reads — when the black end clipped to zero.
The canvas looks soft. That is the Blur slider with Display set to Processed. Switch Display to Raw to see the scan as scanned. Blur affects sampling and the preview, never the reports.
Curves
The new curve makes the print worse.
Almost always the export was stacked on top of the old curve instead of
replacing it. The exported .acv already contains the curve you loaded in
the Curve section — swap it in.
The exported curve is nearly a straight line. That means the measurement found little to correct: the print is already close to linear. Confirm with σ (residual) in the statistics panel.
The Curve chip says “(missing)”.
The .acv moved or the volume it lives on is offline. Pick it again with
Browse…; the stale entry is dropped from the recents list.
Files and sessions
A session opened but the image did not. The scan was moved, renamed, or lives on a volume that is not mounted. Re-open the image with Open Wedge; the rest of the session — quad, grid, cell order, sliders, notes — stays as restored.
⌘S asked for a location even though I saved earlier.
That is by design after a launch, or after opening a different image: what
was restored is a working state, not the document you named, so the app will
not overwrite your last saved .wdge on the strength of it. Save once and
⌘S writes in place from then on.
A RAW file will not open. The app opens what macOS itself can decode — DNG, NEF, CR2/CR3, ARW, ORF, RAF, RW2. A very new camera model may need a macOS update. Exporting a TIFF from your RAW converter always works.
Export ICC Profiles… refuses. It needs at least two measured steps with real tonal range between them. Measure the wedge first.
Display and windows
A panel is too small. Every divider is draggable: between canvas and inspector, between the top half and the bottom panel, and between the three bottom columns. Sizes are remembered.
The theme is wrong.
View → Dark / Light / MidtoneLab / System, or the sun/moon button at the
right end of the toolbar. ⌥⌘D and ⌥⌘L are the shortcuts. The active
theme is greyed out in the menu.
Zoom shortcuts do nothing.
⌘+, ⌘−, ⌘0 and ⌘9 need an image loaded. ⌘+ is typed as
⌘+Shift+= on a US layout.
Getting help
Bugs and feature requests:
github.com/yutakas/StepWedgeDensitone-releases/issues.
Including the .wdge session and the scan makes a report far easier to act
on. Help → Acknowledgments lists the third-party components and their
licences.