Photography – With data recording – Optical
Reexamination Certificate
1998-11-06
2001-03-13
Rutledge, D. (Department: 2851)
Photography
With data recording
Optical
C396S544000
Reexamination Certificate
active
06201933
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to photographic image modifying equipment, and more particularly, to photographic image modifiers for introducing to a photographic negative during its exposure of an image a special effect such as an effect which is indicative of a painting.
2. Description of Related Art
The art of creating special effects in the field of photography has been very active in the past and continues to grow with the increasing interest in photography and the desire for more interesting visual illusions. Devices have been developed, for example, to alter an image prior to or during its exposure on film. Typically, these devices are attached at the end of the lens of a camera, and directly interfere with the light prior to it reaching the film. The alterations or effects applied to the incoming light vary from common color-filtering changes to superimposing “sub-images” onto the same frame of film that is recording the “real” image. For example, placing an opaque, pre-shaped matte in front of a portion of the incoming light will block a correspondingly shaped portion of the film. This results in an unexposed area of film which may be later “filled-in” with another image to create one desired illusion or effect. Similar diffusion mattes are used in “still photography” to produce progressively under-exposed boarders to a frame of film being exposed, creating a vignette boarder.
Conventional devices have also been used to superimpose an image of characters such as a date or other alpha-numeric information onto a portion of an image on a frame of film. Typically, these devices, such as the device disclosed in U.S. Pat. No. 1,504,959 issued to Leschbrandt, include a translucent plate (or ribbon) having, for example, opaque characters positioned at the film plane in a camera. The plate of characters is aligned adjacent to and in front of the surface of the film. Light from an external source or light generated from within the camera is used to superimpose selected characters of the plate onto a portion of the film.
U.S. Pat. No. 3,916,423, issued to Ueda et al. discloses a device for transposing information (characters, lines or designs) onto the surface of film during exposure of the film to an image. A transparent plate having an opaque mask is attached to a film cartridge in front of and adjacent to a frame of film. During exposure, a portion of the light from the image is blocked by the opaque mask located on the transparent plate prior to the light reaching and exposing the film. The result is under-exposed regions of the film (negative) corresponding to the particular shape of the opaque mask. When the negative is used to expose a positive print, the shape of the particular opaque mask will be positively transposed in the form of dark overexposed regions in the final print.
One limitation with these prior art special effects devices is that they all rely on blocking a portion of the incoming light prior to the light reaching the film. Although many effects may be created using the prior art methods employing opaque masks, many other effects require more subtle, diffusion methods.
Oftentimes, when a photograph is taken of a particular subject within a particular scene, the lighting conditions and lighting distribution within the scene and the reflective characteristics of the subject will cause areas on the film negative to become either overexposed or underexposed relative to the “normal” exposure range of the film. A conventional camera usually includes at least one integral light meter which is used to measure the average intensity of light entering the camera prior to exposing the film. The light meter generates an electrical signal that is interpreted by a computer and is used to control either the size of the aperture of the lens, the speed of the shutter, or both, so that the average intensity of light is compensated throughout the entire picture, as recorded by the film. With some more advanced cameras, such as the N-90, N90s, and F5 cameras manufactured by Nikon of Tokyo, Japan, several separate light meters are used, each measuring the intensity of light within a particular zone or region of the frame (an upper region is used to measure the intensity of light from the sky of the scene, for example. Although the use of several light meters to measure the different light intensities at different regions of a framed scene provides a more accurate average light intensity reading, the camera cannot control the amount of light from a particular region of the framed scene reaching the corresponding region of the film without effecting the amount of light reaching the other regions of the film. In other words, the overall density of the negative can be corrected by adjusting either the aperture of the lens or the operating speed of the shutter, however, this exposure correction has a uniform effect over the entire recording area of the film (i.e., the frame). If the aperture is decreased to lessen the amount of light reaching the film to compensate for the “bright” spots of the subject or scene, for example, the otherwise “neutral” or normal areas of the subject or scene will now become too dark. If the speed of the shutter is prolonged to “burn in” the darker regions of the image, the normal areas will become unacceptably overexposed and appear “washed out”.
Unfortunately, since a conventional camera merely measures the average of the total received light entering the camera of a particular image, many pictures end up with a portion of the recorded image either overexposed (to dark) or underexposed (washed out).
In an attempt to prevent this relatively common exposure malady from ruining an otherwise good picture, serious photographers have made it common practice to take several pictures of the same image (i.e., bracket the image) and then vary the exposure of the image between each shot, (typically around ⅓ EV) so that each image offers a slightly different exposure from which the photographer may later select the recorded image that averages the received light most accurately. The above-identified N-90 manufactured by Nikon offers a bracketing feature with its M-26 data-back accessory which allows the camera to automatically take a selected number of pictures and vary the exposure a preset degree between shots.
There are several problems with the bracketing technique of photography. Not only is a lot of film exposed for few different images, only relatively expensive cameras offer exposure control, let alone automatic bracketing of the exposure. Also, although exposure bracketing provides several pictures to select from, since the camera's exposure meter must account for the total received light and may not locally correct the exposure of a portion of the image frame, all of the bracketed pictures will show varying degrees of over and under-exposure. In other words, if there is an overexposed region of an image, bracketing will not correct the exposure of that particular region, merely hide it by changing the total exposure throughout the image, as recorded by film.
Other attempts have been made to control the exposure of a particular region of a frame of film, without effecting the exposure of the other regions of the frame of film. Special segmented, or zone filters include regions of varying opacity which may be aligned within a particular scene to compensate for highlighted regions, such as a cloudy sky. These filters rarely align with the image detail and are only useful when the specific regions defined by the filter align with the regions of the scene.
Once a negative is developed, any underexposed or overexposed regions may be compensated during the production of a photographic print using well known techniques known as “dodging” or “burning” in which a density mask (made from opaque and semi-transparent sheet material) is held in the exposure path (over the photographic paper) when a print is being made from a negative. The mask is used to selectively protect overexposed areas of the n
Darby & Darby
Rutledge D.
Smartlens Corporation
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