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The hyperfocal distance has a property called "consecutive depths of field", where a lens focused at an object whose distance from the lens is at the hyperfocal distance H will hold a depth of field from H/2 to infinity, if the lens is focused to H/2, the depth of field will be from H/3 to H; if the lens is then focused to H/3, the depth of ...
Depth of field depends on the focus distance, while depth of focus does not. Depth of focus can have two slightly different meanings. The first is the distance over which the image plane can be displaced while a single object plane remains in acceptably sharp focus; [1][2] [clarify] the second is the image-side conjugate of depth of field.
Comparison of f /32 (top-left half) and f /5 (bottom-right half) Shallow focus with a wide open lens. Depth of field increases with f-number, as illustrated in the image here. This means that photographs taken with a low f-number (large aperture) will tend to have subjects at one distance in focus, with the rest of the image (nearer and farther ...
Diagram showing circles of confusion for point source too close, in focus, and too far In optics , a circle of confusion (CoC) is an optical spot caused by a cone of light rays from a lens not coming to a perfect focus when imaging a point source .
With no modification to the microscope, i.e. with a simple wide field light microscope, the quality of optical sectioning is governed by the same physics as the depth of field effect in photography. For a high numerical aperture lens, equivalent to a wide aperture, the depth of field is small (shallow focus) and gives
Reducing the aperture size (increasing the f-number) provides less light to sensor and also increases the depth of field (by limiting the angle of cone of image light reaching the sensor), which describes the extent to which subject matter lying closer than or farther from the actual plane of focus appears to be in focus. In general, the ...
The field diaphragm is then partially closed; the edges of the diaphragm should be in the same conjugate image planes as the specimen, therefore should appear in focus. The focus can be adjusted by raising or lowering the condenser lenses and diaphragm. Finally, the field diaphragm is reopened to just beyond the field of view.
The hyperfocal distance has a curious property: while a lens focused at H will hold a depth of field from H/2 to infinity, if the lens is focused to H/2, the depth of field will extend from H/3 to H; if the lens is then focused to H/3, the depth of field will extend from H/4 to H/2.