A hybrid image processing system with active feedback is capable of producing patterns that oscillate in space and time. The term ‘hybrid’ implies a combination of optical and TV-electronic components in our feedback system, where the TV camera looks at its own monitor. Some of the observed oscillating patterns are without precedence, especially if the imaging process from monitor to camera target is ‘non-congruent’. The term ‘non-congruent’ implies that the signal from a given point on the monitor will not return to its former place after passing through the loop. Image rotation and magnification mismatch are prominent examples of ‘non-congruent’ processes in that context. One goal is to study the generation of these fascinating picture oscillations. Another goal is to learn how to prevent these oscillations in situations where they are undesirable, as, for example, in transfer-function synthesis by active feedback.