(A) The random-access imaging system uses a parabolic reflector to image samples directly on a fast machine vision camera located at the focal point of the mirror (f M). Single-element plano-convex lenses are used as objectives, with samples positioned at their focal point (f L). Samples are sequentially illuminated using a LED array controlled by an Arduino microcontroller: a sample is only projected on the sensor when its corresponding LED is ‘on’. See Figure 1—figure supplement 1 and Table 1 for details. (B) (top) Sample s, is captured at time t, on frame f. For a total of n samples, each sample is captured once every n frames; (bottom) a smaller subset of samples can be imaged at higher temporal resolution by reducing the number of LEDs activated by the microcontroller. (C) Image magnification: the chief ray (dashed line) arrives at the detector plane at an incidence angle θ which increases with lateral displacement, y. The image is stretched in the direction parallel to y by a factor of L/l. (D) The image is isotopically magnified as the distance between the mirror and the image increases (V2>V1) as y increases. (E) The combined magnification, MC, shows the impact of the combined transformation on the magnification in both image dimensions (y' parallel to y, and x' orthogonal to y). Red dots (measured) and dashes (predicted) show magnification in y', and blue dots (measured) and dashes (predicted) show magnification in x', inset shows Images of a grid (200 μm pitch) taken with y = 70 mm, left is the uncorrected image and right shows the correct image using Equation 1.