Instead of limiting the frequency of the “send” action, just nip it in the bud. Whenever the cell for your control ultimately decides it’s ready to send an action, it goes through the sendAction:to: method. By subclassing the control and placing a date throttle on the method, you can achieve whatever throttling you feel is appropriate. Here are the guts of my “Slow NSSlider” subclass…

To create an image that accurately depicts what the photographer intended, the photographer must be aware of the color of light and must make adjustments when necessary. The subject of the color of light, and the techniques of dealing with it, are referred to as white balance—the subject of this article. The tools and techniques that photographers use to deal with white balance will be covered at the conceptual level. The actual implementation of these tools and techniques vary from camera to camera and are beyond the scope of this article. It is left up to the photographer to look up the instructions in his camera manual.