Plural focal-plane imaging
An imaging system captures focused imagery from two or more focal planes, yet does so with relatively simple optical elements. Some arrangements involve folded optical paths, to make them more compact in size. Others enable the image sensors to be mounted in coplanar arrangement. Still others involve digital compositing, e.g., to mitigate undesired bokeh effects. A great variety of other features and arrangements are also detailed.
1. An apparatus comprising:
first and second image sensors;
a first optical arrangement, including at least a first lens, the first optical arrangement serving to focus a first image from a first focal plane on the first image sensor; and
a second optical arrangement, including at least a first reflector, the second optical arrangement serving to focus a second image from a second focal plane on the second image sensor;
wherein a portion of the first optical arrangement partially occludes an optical path to the second image sensor and wherein the first focal plane is different than the second focal plane, and wherein the second optical arrangement further includes a curved reflector having a central axis that is non-parallel to a central axis of the first lens, and an image plane of the second image sensor is non-parallel to the second focal plane; and
wherein the curved reflector is a convex reflector which is configured to reflect light directly onto the second image sensor.
2. The apparatus of claim 1 in which the first and second image sensors are coplanar.
3. The apparatus of claim 1 that further includes a third optical arrangement, the third optical arrangement including a third image sensor on which a third image from a third focal plane is focused, the third focal plane being different than the first and second focal planes.
4. The apparatus of claim 1 , wherein the first reflector is a concave reflector.
5. The apparatus of claim 4 , wherein the second optical arrangement is configured such that the first reflector reflects light directly onto the curved reflector.
6. The apparatus of claim 1 , wherein the first optical arrangement includes a second reflector.
7. The apparatus of claim 6 , wherein the second reflector is disposed in an optical path to the first image sensor at a location between the first lens and the first image sensor.
8. The apparatus of claim 7 , wherein the first optical arrangement is configured such that the second reflector reflects light directly onto the first image sensor.
9. The apparatus of claim 6 , wherein the second reflector is a planar reflector.
10. The apparatus of claim 1 , wherein an image plane of the first image sensor is parallel to the image plane of the second image sensor.