Automatic Brightness Control on the 9400 Laryngeal Strobe Among the product enhancements of the Laryngeal Strobe, Model 9400, over the previous generation Model 9100B stroboscopy light source, is the Automatic Light Adjustment mode, which maintains the desired image brightness level by automatically adjusting the light output during an endoscopic procedure. The Brightness up/down arrows on the front panel of the 9400 are used to set the desired brightness level to be maintained by the automatic   adjustment. The amount of adjustment needed is  determined by the brightness detected in the video input to the 9400. This feature is useful in situations where a flexible scope is being passed transnasally, or as the rigid or flexible scope tip gets closer to, or farther away from, laryngeal structures. Another example of varying distance from the scope tip is when there is laryngeal elevation, such as when a patient is performing a pitch glide. Two schemes are available for detecting the brightness of the video image, Average and Peak. When Average is selected, brightness level is adjusted with respect to the average brightness of the entire video image, excluding the mask area of the scope. This setting is used in most cases, especially once the scope has been passed and properly positioned for viewing the laryngeal and pharyngeal area. When Peak is selected, the level is adjusted with respect to the peak brightness detected in the video image (i.e., the brightest part of the image) and may be useful if viewing a structure very close to the scope tip. As with the previous version (9100B), the brightness can also be adjusted manually.