Diaphragm (optics) curved blades improve the roundness of the iris opening. In a photograph, the number of blades that the iris diaphragm has can be guessed by counting the number of diffraction spikes converging from a light source or bright reflection. For an odd number of blades, there are twice as many spikes as there are blades. In case of an even number of blades, the two spikes per blade will overlap each other, so the number of spikes visible will be the number of blades in the diaphragm used. This is most apparent in pictures taken in the dark with small
Electromagnetic diaphragm of capacitive sensor, and shares properties with condenser microphones. The difference between the electromagnetic diaphragm and a condenser microphone is that a condenser microphone operates on the basis of air transmission, has a very thin membrane instead of a diaphragm, and cannot be placed against a body to sense sounds within the body. The electromagnetic diaphragm for stethoscopes was patented by Clive Smith in 2002 and is used on Thinklabs electronic stethoscopes. Electromagnetic diaphragm An electromagnetic diaphragm is a form of capacitive sensor used on an electronic stethoscope. The diaphragm is coated with a conductive material. A conductive plate is