| 摘要 |
A case hinges to the side of the movie camera next to the ground glass. One end of a viewfinder tube mounts pivotally to the case; the other supports an ocular. Light from the inverted image on the ground glass passes, at a right angle to the camera side, into the case. An Amici prism in the case reerects the image and reflects the light rearward to a beam splitter. The splitter passes part of the light rearward to a 45 DEG /90 DEG prism and then upward through a lens and iris to a video port and neutral-density filter. The beam splitter deflects the rest of the light outward, at a right angle to the camera side, into the finder tube. There another 45 DEG /90 DEG prism (that rotates with the tube) deflects the light rearward in the tube to a lens that reimages the scene at the ocular. The movie camera can thus be tilted while the tube and ocular are at constant height, but prism rotation twists the image about the optical path. To correct this, a Pechan prism between the lens and the ocular is linked to rotate about the path when the finder tube pivots. The Pechan prism counterrotates the image. (The lens and Pechan prism introduce two additional image inversions.) In the finder are also a filter wheel and optional 2x reducing lens.
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