Original painting, overlaid for comparison

A Bar at the Folies-Bergère

Manet, 1882 · 96 × 130 cm · Courtauld Gallery. Rebuilt in metres from the canvas, with four ways to read the mirror. All paintings

Walk: drag to look, W A S D to move, Q E for height, Shift to run.

How does the mirror work?

As paintedEverything behind the glass is placed exactly where it appears, with the glass left open. A real flat mirror, viewer in the middleThe natural reading. A customer stands at the right edge, and a real mirror shows what it would show. She movedThe reflected barmaid is the same woman a moment later, standing to the right. A ghost stands there. One viewpoint, off to the sideMove the camera sideways until her reflection slides away from her. How far does it go?

Rendering

Fast preview Path traced

Path tracing turns the glass into a real mirror, so you can see what it would actually show. Samples: 0

Bounces5

Light

Azimuth Elevation Intensity Softness Lamp glow Exposure Fill (preview) Show light position

How far is the glass?

The painting does not say how far the mirror stands behind her. This is the main unknown in every theory.

Gap behind her

Check against the painting

At Viewer's eye the render sits exactly under the original. Fade it in to see where the model and canvas agree.

Overlay Difference blend Floor grid (0.5 m) Measure: click two points

How it was measured

Canvas	130 × 96 cm
Reference scale	0.102 cm / px
Horizon	row 399 of 956
Focal length	1700 px
Viewing distance	1.73 m
Eye height	1.45 m (assumed)
Counter top	0.95 m (assumed)
Depth of a counter point	f · 0.5 / (row − horizon)

Bottles stand on the counter, so their bases give their depth. The barmaid's depth follows from her head height, which comes out at a natural 22 cm when she stands 2.05 m away. Eye height and counter height are assumptions; the room hangs together across a range of values.

Checks that were not fitted

Champagne bottle	0.28 m
Barmaid's head, with fringe	0.22 m
Mandarins	5 cm
Counter top (assumed)	0.95 m
Mirror's lower ledge (solved)	0.96 m
Barmaid's eye height	1.73 m

The ledge is the best test. The gold strip under the mirror was solved from its own pixels at the mirror's distance, and lands within a centimetre of the counter height. The barmaid's eyes come out a little high for a woman of the period, so she may stand on a duckboard or Manet raised her.

Confidence

Measured Bottle positions and sizes, counter, mirror ledge, barmaid's head size, the man's reflected position.

Inferred Viewing distance, eye height, the gap between her and the mirror, the customer's position outside the right edge.

Invented The hall behind the viewer, the crowd, her hidden legs, the floor, the room on either side.

Open question. The reflected barmaid looks about as large as the real one. A mirror 20 cm behind her would make her reflection about 16 percent smaller. Either the glass is much closer than that or the reflection was painted by eye.