Nature Communications (2026). DOI: 10.1038/s41467-026-72287-x"> Fourier spectrum of an intensity image under an oblique illumination angle. Credit: Nature Communications (2026). DOI: 10.1038/s41467-026-72287-x

Anyone who has ever used a microscope knows that it takes time to bring a sample into sharp focus. Each time you move the slide, the image blurs, and you have to stop and carefully turn a knob to bring everything back into clear view. For scientists and clinicians, even if the motion is semi-automated, that time quickly adds up as they work with dozens or hundreds of samples.

Now a team of scientists at Caltech has developed an inexpensive, robust fix for this problem that involves little more than a couple of LED lights and some physics-based processing.…