On Wed, Aug 28, 2013 at 10:12 AM, Darren Addy <pixelsmi...@gmail.com> wrote:
> http://www.thephoblographer.com/2013/08/28/nikon-patents-an-electronically-controlled-lowpass-aa-filter/ > > If anyone reads Japanese, perhaps they can explain the details. OK, so using the diagrams and Google Translate: The idea is that you have two OLPF filters, both made of birifringent material that splits the image vertically based on polarization. (This is similar to the D800E setup. In the D800E, the second OLPF filter is designed to reverse the effect of the first one, to cancel out the OLPF effect. In this patent, the OLPFs have the same orientation.) In between the OLPF filters, this patent adds a liquid crystal filter, similar to the LCDs in your monitor. When the LCD is unpowered, it rotates the polarization of light (so that horizontal becomes vertical and vertical becomes horizontal). When it's unpowered, the polarization is unaffected. With AA scenario: First OLPF splits the image vertically, with one "split" coming from the horizontally polarized component of the image and the other split coming from the vertically polarized component. The light passes through the energized AA filter, and the polarization is unaffected. The second OLPF has the same effect as the first, doubling the offset between the horizontally and vertically polarized components of the image. This separation provides the AA effect. No AA scenario: First OLPF splits the image vertically, with one "split" coming from the horizontally polarized component of the image and the other split coming from the vertically polarized component. The light passes through the de-energized AA filter, which rotates the polarization of the light (swapping horizontal and vertical). Because the polarizations are swapped, the second OLPF cancels out the first, shifting the horizontally and vertically polarized components of the image back into alignment with each other. There is no AA effect. I've had thoughts about Pentax making a switchable AA effect by using the SR system to shift the sensor by ~1px during the exposure. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
