Lens: corrections, vignetting and perspective
Press ⌃4 for Lens. Its three sections are the corrections of the glass and the aim: distortion, falloff and colour fringing first; then a vignette you add on purpose; then perspective.
Lens corrections run first of the geometric steps: after any spot cleans and AI lasso fills, and before perspective, straighten and crop. They undo what the lens did before Vixlo undoes anything you aimed by hand.
Lens corrections
The Lens corrections section opens first on this tab. Its summary names the lens the frame was shot on — no profile for XF23mmF1.4 R — or no profile · aimed by hand when the file does not say.
| Slider | Range | What it does |
|---|---|---|
| Distortion | −100 to +100 | Right corrects barrel distortion, where straight lines near the edges bow away from the middle; left corrects pincushion, where they bow in |
| Vignette — Amount | −100 to +100 | Lightens the corners (positive) to undo the lens's own falloff, or darkens them |
| Vignette — Midpoint | 0 to 100, starts at 50 | How far in the correction reaches; dimmed until Amount leaves 0 |
| Chromatic aberration — Red / cyan | −100 to +100 | Nudges one coloured fringe in or out along high-contrast edges |
| Chromatic aberration — Blue / yellow | −100 to +100 | The other fringe |
Aim Distortion at a line you know is straight — a doorframe, a horizon — and stop when it looks straight. For fringing, zoom in on a corner — hold ⌘ and scroll with the pointer over it, or pinch — find a fringed edge and move the slider until the colour goes; neither slider does anything at the very centre of the frame.
Every slider you let go of in this section, and the section's reset, re-fits the crop. A pincushion correction (Distortion below 0) pulls the frame's edges inward and leaves the corners empty, so the new crop is the largest clean rectangle, the same as after a straighten. While Distortion stays below 0 that holds for every slider here: letting go of the Vignette or a fringe slider fits the crop to the clean rectangle inside the pincushion correction too. A barrel correction, the vignette and the fringe sliders leave no empty corner of their own, but the crop is re-fitted all the same. With no pincushion, straighten or perspective correction on the photograph it goes back to the whole frame; with any of them it is the largest clean rectangle for those. The Vignetting section below does not touch the crop.
A crop you drew by hand is replaced the moment you let go of any slider in Lens corrections. The frame goes back to the whole photograph, or to the largest clean rectangle for whatever straighten, perspective and pincushion correction it carries. ⌘Z brings your crop back. The way around is the order of work: set Lens corrections first, then crop. A crop made afterwards stands until the next change here, in Perspective or in Straighten.
The sentence under the sliders is the answer to the question this section raises: Corrected by hand — Vixlo has no lens profiles, and macOS offers none for these files. There is no camera-profile toggle because there is nothing for one to do. The section has an eye.
Vignetting
The Vignetting section is the creative vignette, separate from the lens's own falloff above it. Its note says where it runs: Creative vignetting, applied after the crop — separate from the lens's own falloff above. It is centred on and shaped by the frame you actually kept.
| Slider | Range | Starts at |
|---|---|---|
| Amount | −100 to +100 | 0 — negative darkens the corners, positive lightens them |
| Midpoint | 0 to 100 | 50 — where the falloff starts, as a fraction of the way from the centre to the frame's edge. At Roundness 0 that holds along the long edge as well as the short one; raising Roundness pulls the long edge's start in toward the short edge's, and lowering it pushes it out |
| Feather | 0 to 100 | 50 — hard at 0, soft at 100 |
| Roundness | −100 to +100 | 0 — the frame's own proportions at 0, rounding toward a circle as it rises |
Amount is the switch; the other three are dimmed until it moves. The section has an eye, and its reset leaves Film grain on the Detail tab exactly as it was.
Perspective
The Perspective section squares up converging verticals and horizontals: a building leaning back because you tilted the camera up, a doorway that should be a rectangle. The section holds the two sliders and the button that lays guides on the canvas.
By the sliders
Vertical and Horizontal each run from −100 to +100. A positive Vertical widens the top of the frame; a positive Horizontal widens the right. The frame follows live and the value is written when you let go.
By guides
- Press Lay guides on the canvas. The button reads Placing guides… and a bar appears under the frame.
- Choose a guided mode on the bar: Vertical lays two lines to drag onto two uprights that converge; Horizontal does the same for two horizontals that should be level; Both puts four corners on something that ought to be a rectangle.
- Drag the ends of the guides onto the lines. While guides are up the frame is shown plain, without its correction or crop, so you lay them on what the camera saw.
- Press Apply — the button in the middle of the frame,
↩, or the bar's own — and the correction is solved and applied.Escor Cancel takes the guides down without writing anything.
After Apply, an Amount slider on the bar scales how much of what was found is applied, from 0 to 100%. The bar also says where the manual sliders are: Vertical and Horizontal are in Lens.
The correction runs before the crop, and the crop follows it: every change sets the crop to the largest rectangle inside the corrected frame, so the empty corners are never shown. A crop you make afterwards stands until the perspective, the straighten or a lens correction changes again, and then it is replaced. Reset perspective on the bar puts it back to 0 and re-fits the crop the same way: the whole frame, or, if a straighten or a pincushion lens correction is still on the photograph, the largest clean rectangle for those. The section has an eye.