A special camera has been installed on a research sailplane to takein situphotographs of atmospheric particles. Ice particle shapes, sizes, and concentrations; raindrop sizes and concentrations; and estimates of cloud droplet concentrations and maximum sizes are obtained from the photographs. The camera is capable of photographing particles as small as about 4 &mgr; radius; the size of the largest particle completely imaged is limited by the 24×36 mm projected area photographed. Liquid particles can be distinguished from ice particles for radii greater than 50 &mgr;. Techniques are described for calibrating the camera so that both in‐focus and out‐of‐focus images are used for obtaining concentration and size data. Examples of photographs of ice particles, raindrops, and cloud droplets are shown. Camera improvements for getting more data for a given length of flight are suggested.