F Diaphragm

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An F diaphragm is used in optics exercises to show that convex lenses invert images. This is essentially a copy of a metal F diaphragm made in the 60s. Optically, the diaphragm works best with a piece of frosted diffusion glass behind it. The diffusor lets you focus on the F and removes the light bulb filament and other details behind it. **Note: the F diaphragm is usually placed near a light source; since halogen lamps produce a fair amount of heat, use ABS or other temperature-tolerant material and not PLA, which will warp. In addition, white is a good color for this print, as it absorbs less heat from the light.**