Whole beam image splitting system
View Patent ↗The present invention comprises methods and apparatuses for causing a single imaging lens system to simultaneously form multiple high resolution images on multiple imaging sensor planes. The images are preferably substantially identical, with no parallax error, except for different light levels so that the multiple images are of sufficient quality and similarity that they may be compared and/or combined (typically pixel-by-pixel) to create a single instantaneous high dynamic range (HDR) image. The invention may be used to create high-resolution HDR snapshots of moving subjects, as well as high-resolution HDR moving pictures (e.g. cinematographic films, movies, or other video) in which the subject and/or camera is moving. Alternatively, the images are substantially identical, or substantially identical except for different focuses.
1. A method for combining color images, the method comprising the steps of:
splitting an image-forming beam into a reflected beam portion and a transmitted beam portion using a whole beam broad spectrum HDRI beamsplitter;
forming a plurality of color images on one or more CFA image sensors, the images being substantially identical except for their light levels; and
combining the images prior to any de-mosaicing of the images to form a high dynamic range color image.
2. The method of claim 1 wherein at least one of the images differs in light level by an amount greater than or equal to one photographic stop from an image having a next closest light level.
3. The method of claim 2 wherein at least one of the images differs in light level by an amount greater than or equal to two photographic stops from an image having a next closest light level.
4. The method of claim 3 wherein at least one of the images differs in light level by an amount greater than or equal to three photographic stops from an image having a next closest light level.
5. The method of claim 1 further comprising splitting the reflected beam portion and/or the transmitted beam portion using one or more additional whole beam broad spectrum HDRI beamsplitters.
6. The method of claim 1 wherein the whole beam broad spectrum HDRI beamsplitter is constructed by coating a surface of a first prism and/or a surface of a second prism with a partially-reflecting coating and bonding the first and second prisms together so the coating is disposed between the first prism and the second prism, the coating thereby forming the whole beam broad spectrum HDRI beamsplitter.
7. The method of claim 6 further comprising the step of pre-correcting aberrations induced in the beam portions by the prisms using a corrective lens system disposed prior to the whole beam broad spectrum HDRI beamsplitter.
8. The method of claim 1 wherein the forming step comprises simultaneously capturing the color images on a plurality of CFA image sensors.
9. The method of claim 1 further comprising the step of assembling the high dynamic range color image together with other high dynamic range color images to create a high dynamic range film or video.
10. The method of claim 1 further comprising the step of effectively collimating the image forming optical beam.
11. The method of claim 1 further comprising the step of correcting aberrations in the beam portions which have been transmitted through the whole beam broad spectrum HDRI beamsplitter.
12. The method of claim 1 further comprising the step of replacing the whole beam broad spectrum HDRI beamsplitter with a different beamsplitter.
13. The method of claim 1 further comprising the step of directing a beam portion to a viewfinder.
14. The method of claim 13 wherein the directing step comprises reflecting the beam portion from one or more shutters or partially reflecting optical elements.
15. The method of claim 1 wherein the whole beam broad spectrum HDRI beamsplitter comprises a partially reflecting beamsplitter coating disposed in the interior of a prism or beamsplitting cube.
16. An apparatus for combining color images, the apparatus comprising:
a whole beam broad spectrum HDRI beamsplitter for splitting an image-forming beam into a reflected beam portion and a transmitted beam portion;
one or more CFA image sensors for capturing a plurality of color images, said images being substantially identical except for their light levels; and
a processor for combining said plurality of color images prior to any de-mosaicing of said images to form a high dynamic range color image.
17. The apparatus of claim 16 wherein at least one of said images differs in light level by an amount greater than or equal to one photographic stop from an image having a next closest light level.
18. The apparatus of claim 17 wherein at least one of said images differs in light level by an amount greater than or equal to two photographic stops from an image having a next closest light level.
19. The apparatus of claim 18 wherein at least one of said images differs in light level by an amount greater than or equal to three photographic stops from an image having a next closest light level.
20. The apparatus of claim 16 further comprising one or more additional whole beam broad spectrum HDRI beamsplitters for splitting said reflected beam portion and/or said transmitted beam portion.
21. The apparatus of claim 16 wherein said whole beam broad spectrum HDRI beamsplitter is selected from the group consisting of a thin beamsplitter, a glass plate, a pellicle, a doublet lens, an achromatic cemented doublet, and a partially reflecting beamsplitter coating disposed in the interior of a prism or beamsplitting cube.
22. The apparatus of claim 16 wherein said whole beam broad spectrum HDRI beamsplitter comprises a deposited partially-reflective layer disposed between two prisms.
23. The apparatus of claim 22 wherein said prisms are bonded together.
24. The apparatus of claim 16 further comprising a corrective lens system disposed prior to said whole beam broad spectrum HDRI beamsplitter.
25. The apparatus of claim 16 comprising a plurality of CFA image sensors configured to capture said plurality of color images simultaneously.
26. The apparatus of claim 16 further comprising a processor for assembling said high dynamic range color image together with other high dynamic range color images to create a high dynamic range film or video.
27. The apparatus of claim 16 further comprising a collimating lens system for effectively collimating the image forming optical beam.
28. The apparatus of claim 16 further comprising a corrective lens system.
29. The apparatus of claim 16 further comprising a stage comprising one or more replacement beamsplitters.
30. The apparatus of claim 29 wherein said stage is circular or linear.
31. The apparatus of claim 16 further comprising a viewfinder.
32. The apparatus of claim 31 further comprising one or more shutters or partially reflecting optical elements for directing a beam portion to said viewfinder.