Power Generator
Imaging Lens
Image Sensor
Polyoptic Wheel
Viewfinder, Eye
LED Flash
LCD Display
Image Processing

Downloadable PDFs

Introduction      Optics      Stencil      Human Eye      Illustrations

Viewfinder Stencil

The viewfinder's goal is to help the photographer frame a photo by providing the same view as that captured by the camera. However, Bigshot's polyoptic wheel has different types of lenses on it, each producing a different horizontal field of view (FOV). The wheel has three settings − regular with a 40° FOV, wide-angle with an 80° FOV, and stereo with a 16° FOV. For each setting, Bigshot's viewfinder needs to convey the appropriate field of view to the photographer.

Figure 3: Viewfinder stencils

Bigshot achieves this with a simple trick. The two viewfinder lenses (objective and eyepiece) are designed to produce a field of view that is larger than any of the lens settings. As shown in Figure 3, the top half of the polyoptic wheel has three cutouts, or stencils, that are used to mask the viewfinder's field of view. These stencils are appropriately sized and positioned so that, for each lens setting, the correct field of view is seen by the photographer. Click on the three buttons in Figure 3 so see the viewfinder stencils in action. For each setting, the image on the right shows what the photographer sees.