Ambient depth-of-field simulation exposuring method
First Claim
1. A method to view sharpness of background or foreground objects in a viewfinder of an autofocusing camera without having to change aperture, said method comprising the steps of:
- selecting an appropriate relationship between a simulated depth and a plurality of input parameters including aperture value, focal length, and measured depth;
measuring depths of a main object and a background or foreground object using said autofocusing camera;
selecting a pre-determined focal length;
selecting a first pre-determined aperture at which a picture will be taken;
selecting a second aperture at which an object will be viewed from said viewfinder;
calculating a simulated depth of background or foreground using said relationship and input parameters including said measured depths, and said first and second selected apertures; and
using said autofocusing camera to display a simulated background or foreground image in said viewfinder at said calculated simulated depth.
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Accused Products
Abstract
A method to view sharpness of background or foreground object in a viewfinder of an autofocusing camera without having to change the aperture. The method involves first selecting an appropriate relationship between a simulated depth and a plurality of input parameters including aperture value, focal length, and measured depth. A circle of confusion is calculated using the measured distances of a main object and a foreground or background object, and the aperture value at which the picture is to be taken. The circle of confusion is then used to calculate the simulated background or foreground depth using the maximum aperture value, or any aperture value at which the objects will be viewed. Finally, the simulated depth is used to adjust the focal length and display a simulated background or foreground image through the viewfinder. If the sharpness of the simulated image is not satisfactory, a new aperture value can be selected and the simulation process repeated. Alteratively, a predetermined value of circle of confusion can be stored in the camera to calculate the depth-of-field relative to the main object and display the calculated values through the viewfinder.
151 Citations
6 Claims
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1. A method to view sharpness of background or foreground objects in a viewfinder of an autofocusing camera without having to change aperture, said method comprising the steps of:
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selecting an appropriate relationship between a simulated depth and a plurality of input parameters including aperture value, focal length, and measured depth; measuring depths of a main object and a background or foreground object using said autofocusing camera; selecting a pre-determined focal length; selecting a first pre-determined aperture at which a picture will be taken; selecting a second aperture at which an object will be viewed from said viewfinder; calculating a simulated depth of background or foreground using said relationship and input parameters including said measured depths, and said first and second selected apertures; and using said autofocusing camera to display a simulated background or foreground image in said viewfinder at said calculated simulated depth. - View Dependent Claims (2, 3)
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4. A method to view and adjust sharpness of background or foreground objects in a viewfinder of an autofocusing camera without having to change aperture, said method comprising the steps of:
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(a) selecting an appropriate first pre-determined aperture value Nold, at which a picture will be taken, and a focus value Fold, and recording both Nold and Fold values; (b) bringing into focus a main object, measuring distance Dold from said main object and recording said Dold value; (c) if zooming is used, then recording an after-zoom focus value Fnew ; (d) bringing into focus an object from background or foreground and measuring and recording distance T from said background or foreground object; (e) performing a field depth simulation computation which comprises the following steps; (i) selecting an appropriate simulation equation which relates a simulated distance Dnew with a plurality of input parameters including a measured distance, a predetermined aperture value, the selected focus value Fold or Fnew, and a circle of confusion C; (ii) using said distance from said main object as said measured distance, said distance from said background or foreground object as said simulated distance, the value of Fold or Fnew depending on whether zooming is used, and said first predetermined aperture value, Nold, to compute the circle of confusion value C using said simulation from step (e)(i); (iii) using said distance from said background or foreground object as said measured distance, a second predetermined aperture value, at which said background or foreground object will be viewed, the value Of Fold or Fnew depending on whether zooming is used, and said circle of confusion value C obtained from step (e)(ii) to compute a simulated distance Dnew corresponding to said background or foreground object; (f) moving lens focus to correspond to said simulated distance value Dnew and displaying an image of said background or foreground object through said viewfinder of said autofocusing camera; and (g) if the image sharpness of the background or foreground object is not satisfactory, then changing the first pro-determined aperture value Nold in steps (a) and (e)(ii) and repeating steps (e)(ii) through (f); (h) moving lens focus from Dnew back to Dold, and focus value to Fold, if necessary; (i) measuring exposure value and determining an appropriate shutter speed value; and (j) pressing a shutter button for exposure. - View Dependent Claims (5, 6)
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Specification