The amount of light recorded by a camera depends on the size of the lens opening (called the aperture) and the amount of time light is allowed to strike the film or sensor chip (called the exposure time). The former is controlled by varying the f/stop, a.k.a. F-number, and the latter is controlled by varying the shutter speed. In a digital camera it is also possible to vary its sensitivity to light by amplifying the voltage observed at each pixel position before converting that voltage to a number. The amount of amplification is called the ISO number. Unfortunately, each of these variables has a side effect: opening the aperture also decreases depth of field, lengthening the exposure time also increases motion blur (including motion blur due to camera shake), and increasing the ISO number also increases image noise. In this applet, we explore these tradeoffs.