Patent US4542959A successfully refreshed from Google Patents.
US4542959A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color correction filter and method of taking underwater photographs therewith
Assignee: Legacy Systems LLC
•
Filing: 1983-07-25
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Granted: 1985-09-24
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Expires: 2003-07-25
Abstract
Abstract A color correction filter is disclosed, which is especially adapted for use in underwater photography. The filter has a transparent element which passes impinging light wavelengths as follows: ______________________________________ % incident light Light wavelength, nm transmitted ______________________________________ 400 25 450 12 470 8 500 4 520 7 570 50 600 87 700 90 ______________________________________ A method of taking underwater photographs utilizing this filter is also disclosed. The method includes causing daylight to travel through seawater to the subject, and reflected light from the subject to the camera, over a total distance of less than about 50 feet.
Inventors
- 👤 Kirk Kreutzig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:29
CPC Classifications
G; G02; G02B; G02B23/00; G02B23/16; G02B23/22; G02B5/00; G02B5/20; G02B5/22; G02B7/00; G02B7/006; G03; G03B; G03B11/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
74 words
A color correction filter for use in underwater photography, comprising, in combination, mounting means for mounting the filter to a camera to be used underwater, and a transparent element secured to the mounting means and passing impinging light wavelengths as follows: ______________________________________
Light % incident light
wavelength, nm transmitted
______________________________________
Below 370 0
400 25
410 27
450 12
470 8
500 4
520 7
550 18
570 50
600 87
700 90.
______________________________________
Claim 2
Dependent Claim
74 words
A color correction filter for use in underwater photography, comprising, in combination, mounting means for mounting the filter to a camera to be used underwater, and a transparent element secured to the mounting means and passing impinging light wavelengths as follows: ______________________________________
Light % incident light
wavelength, nm transmitted
______________________________________
Below 370 0
400 25
410 27
450 12
470 8
500 4
520 7
550 18
570 50
600 87
700 90.
______________________________________
Claim 3
Dependent Claim
22 words
A color correction filter for use in underwater photography according to claim 1 wherein said transparent element is formed of colored glass.
Claim 4
Dependent Claim
28 words
A color correction filter for use in underwater photography according to claim 1 wherein said transparent element is formed of optical glass having substantially constant light-passing properties throughout.
Claim 5
Dependent Claim
23 words
A color correction filter according to claim 1 wherein said mounting means is adapted for connection to the front of a camera lens.
Claim 6
Dependent Claim
36 words
A color correction filter according to claim 1 wherein said mounting means is adapted for connection to the rear of a camera lens at a position between the lens and the film plane of the camera.
Claim 7
Dependent Claim
67 words
A color correction filter for use in underwater photography comprising, in combination, mounting means for mounting the filter to a camera to be used underwater, and a transparent element secured to the mounting means and passing incident light wavelengths as follows: ______________________________________
% incident light
Light wavelength, nm
transmitted
______________________________________
400 25
450 12
470 8
500 4
520 7
570 50
600 87
700 90.
______________________________________
Claim 8
Dependent Claim
67 words
A color correction filter for use in underwater photography comprising, in combination, mounting means for mounting the filter to a camera to be used underwater, and a transparent element secured to the mounting means and passing incident light wavelengths as follows: ______________________________________
% incident light
Light wavelength, nm
transmitted
______________________________________
400 25
450 12
470 8
500 4
520 7
570 50
600 87
700 90.
______________________________________
Claim 9
Dependent Claim
49 words
A color correction filter according to claim 6 wherein said transparent colored element is less than 0.25 mm thick, and wherein said mounting means is adapted to locate said transparent colored element less than 0.25 mm from the rear surface of the rear optical element of the camera lens.
Claim 10
Independent Claim
118 words
A method of taking underwater photographs comprising the steps of placing a light filter between a photographic subject and photographic film in association with a camera and lens, placing the camera, lens, and filter in cyan water at a depth of from about 8 feet to about 50 feet, causing daylight to travel through the seawater to the subject, and from the subject through seawater and through the filter and lens, filtering the light wavelengths passing through the filter as follows: ______________________________________
% incident light
Light wavelengths, nm
transmitted
______________________________________
400 25
450 12
470 8
500 4
520 7
570 50
600 87
700 90
______________________________________ and causing the filtered light to impinge upon a color-responsive material.
Claim 11
Independent Claim
118 words
A method of taking underwater photographs comprising the steps of placing a light filter between a photographic subject and photographic film in association with a camera and lens, placing the camera, lens, and filter in cyan water at a depth of from about 8 feet to about 50 feet, causing daylight to travel through the seawater to the subject, and from the subject through seawater and through the filter and lens, filtering the light wavelengths passing through the filter as follows: ______________________________________
% incident light
Light wavelengths, nm
transmitted
______________________________________
400 25
450 12
470 8
500 4
520 7
570 50
600 87
700 90
______________________________________ and causing the filtered light to impinge upon a color-responsive material.
Claim 12
Dependent Claim
25 words
A method of taking underwater photographs according to claim 8, including the step of causing said filtered light to impinge upon daylight-type balanced photographic film.
Claim 13
Dependent Claim
30 words
A method of taking underwater photographs according to claim 8, including the step of locating the subject at a distance of from 1 to about 10 feet from the camera.
Claim 14
Dependent Claim
54 words
A method of taking underwater photographs according to claim 8, including the step of causing the daylight to travel a total distance of from about 8 to about 50 feet through seawater from the sea surface to the subject and thence from the subject to the filter prior to its passage through the filter.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-23 | 1989-03-25 | 1989-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-23 | 1993-03-25 | 1993-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-23 | 1997-03-25 | 1997-09-24 | $7700.00 | Window Closed / Lapsed |