Panasonic AG-DVX200 Tech Brief - Volume 3 - Page 3

cess called "oversampling" -- it reads a much bigger patch of pixels, and scales them down to the nal image size. In reality the DVX200 is reading a patch of approximately 4,787 x 2,692 pixels, and scaling it down to 3,840 x 2,160 for recording. e result is very, very sharp images, signi cantly sharper than they would have been had the camera merely read out 3,840 x 2,160 in the rst place. Reading out this many pixels does take quite a bit of time, and so this mode is only available at the slower frame rates of 24/25/30, and not at the faster frame rates of UHD 50/60. 4K: 4096 x 2160 @ 24.00 Frames Per Second e 4K mode delivers a 17:9 aspect ratio, at a frame size of 4,096 x 2,160, at 24.00 frames per second. is mode delivers a slightly wider wide-angle eld of view, approximating what a 29.5mm lens would look like on a full-frame photography camera. As compared to the UHD 24/25/30 mode, the height is the same, but the width is slightly expanded to include additional pixels on each side; that wider width gives the sensor the ability to "see" more of the image that the lens is projecting onto it, and the result is a wider image at the same focal length, e ectively giving a wider eld of view. Because this mode runs at a slightly slower frame rate than UHD (24.00 fps, vs. 29.97 max for UHD), there's time to read in some more pixels on the sides of the frame. e total frame size is approximately 13.35 million pixels, in a grid of approximately 5,032 x 2,654. at's a signi cant amount of oversampling; the DVX200 in 4K mode is basically operating internally as a "5K" camera; it uses a 5K-sized patch of the chip to create its 4K rendered frame. Because of the oversampling, the DVX200 renders an image that is just about as sharp as a 4K recording can hold. UHD: 3840 x 2160 @ 50.00 or 59.94 Frames Per Second When operating in UHD at fast frame rates (50 or 60 progressive frames per second), the sensor has to window in notably. Remember that there's only so many pixels that can be read o the sensor in any given period of time; when doubling the frame rate, that reduces the number of pixels that can be read in. e UHD mode at 50 and 60 frames per second uses an 8.71 million pixel sensor patch of approximately 3,934 x 2,213 to create a nal frame size of 3,840 x 2,160. at smaller patch of the sensor results in a narrower eld of view; the UHD 50/60 mode has a eld of view equivalent to a full-frame photography camera with a 37.2mm lens. Even though the UHD 50/60 mode is using fewer pixels than its other recording modes, note that it is still using a fully-sampled eld of pixels (8.71 million) to make its 8.29-million pixel frame. e DVX200 is still delivering Ultra High De nition quality footage with as much resolution as some other 4K and UHD cameras. e eld of view is narrowed in order to reduce the number of pixels that must be read and processed in time. ere is a side bene t to this though -- the UHD 50/60 mode shows signi cantly reduced "rolling shutter" e ect as compared to the 24/25/30 fps modes. Because the total number of pixels read per frame is fewer, the sensor can be scanned faster; the faster the sensor is scanned, the less "rolling shutter e ect" that happens.