This afternoon, I want to describe to you some reactions from our clinical colleagues about how they feel towards automatic bright-ness systems. Perhaps the first point to be made, as has been pointed out, is that radiologists by and large do not understand what an automatic brightness system is or how it works. Some radiologists may have a "textbookish" recollection of what was taught to them at one time in physics, but they don't really have a working knowledge of automatic brightness control systems in general, or of the specific system they are using in particular. With the increasing trend towards pushbutton automatic x ray systems, radiologists are increasingly losing the opportunity to become knowledgable about the systems and about the effects of components of the systems upon image quality. These are concerns I have heard many radiologists express. They also express some concern for retaining manual control of fluoroscopy for certain examinations, and desire an automatic brightness controlled fluoroscopic system which also provides manual capability. Another prob-lem which has been mentioned during my discussions with radiologists is the problem of large area sensing. This problem has been discussed by several speakers already, and I have little to add to this discussion. There apparently is a problem concerning movement of the x ray beam over areas of the upper thorax, esophagus, and neck, and reception in the edge of the field of intense radiation which misses the neck. A third difficulty which was addressed by two of the preceding speakers is the relatively slow response time of automatic brightness controlled systems and the problems this creates when crossing interfaces.