Depth-of-field (DOF) is more than a button on the front of a camera; it is a complex mathematical system that interweaves focal length, focusing distance, and aperture. Many modern SLR/DSLR lenses no longer have complete or accurate DOF markings. So to aid photographers, this ExpoImaging ExpoAperture² Depth-of-Field Guide gives shooters a full scale that can effectively be read with a single glance.
To use the guide, one needs to select the sensor/film size—anywhere from a 2x digital crop factor to 6x6 cm film—then a focal length ranging from 15mm to 135mm. The scale will compensate for the varying film/sensor sizes in relation to the selected aperture. When the parameters are chosen, the guide returns a range of apertures and the corresponding areas that will be rendered in focus for each f-stop.
The ExpoAperture² is compact, and easily finds its home in just about any camera bag or pocket. This ExpoAperture² also includes a CD-ROM with an instruction manual, a printed quick-start guide, a storage pouch and a sensor/film format reference chart.