Some techniques are described that have been developed for the periodic recording of single, fast traces on a cathode-ray tube at rates up to 4000 per second. The factors affecting the maximum writing speed are discussed, and it is shown that speeds as high as 70 cm/μsec. can be obtained without sacrifice of deflection sensitivity and using commercially available tubes and films. Several 16-mm cameras, adaptations of existing models, are described which permit photography of as many as 4000 traces per second. The film in these cameras moves continuously and at high speeds and cannot normally be projected as a moving picture. Where such projection is desired, a camera is employed which provides trigger pulses to initiate the transients synchronously with the film speed. Finally, a technique is presented for placing consecutive identification numbers in each frame area.