Time-delay scatter analysis for the darkest RBE moments in data A (left two columns) and data B (right two columns). First row: Hα images at Δλ = −0.8 Å constructed by selecting the darkest value for each pixel throughout the entire observation duration. The first pair of images is identical except for the green overlays; so is the second pair. Second row: simultaneous and delayed Hα line-core images. Third row: scatter diagrams for each image pair above it. First and third columns: data A and B image pairs with the lower image made up of the same pixels at Hα line center at the same sampling times. Second and fourth columns: data A and B image pairs with the lower image made up of the same pixels, but selecting the darkest value per pixel at Δλ = +0.4 Å during the 2 − 5 min delay range after the upper-image pixel sampling times. The green boxes select specific correlation features with corresponding contours in the image pairs. Online image blinkers: 1–5, 1–6, 3–7, 3–8.