Sony Pixel Shift: Outstanding Results, but Botched Design for Motion Correction Ignores Benefits of Frame Averaging, Increases Noise
Related: botched design, digital sensor, fairy dust aka hot/stuck pixels, frame averaging, imcompetence crisis, noise, pixel shift, Sony, Sony A7R, Sony A7R II, Sony A7R III, Sony A7R IV, Sony A7R V, Sony mirrorless, Sony Pixel Shift, true-color sensor or image
re: Sony pixel shift
re: Sony Pixel Shift: Outstanding Results, but Design for Motion Correction Ignores Benefits of Frame Averaging, Increases Noise
See pages on frame averaging and automated script in Making Sharp Images.
The Sony A7R V and other Sony mirrorless cameas take 4 exposures for a 4-shot pixel shift frame. These 4 frames can be used in 4 ways:
- Assembled with PixelShift2DNG (no motion correction), or Sony Viewer (motion correction) into an ARQ file, which can be directly opened, or converted into a compressed DNG.
- Alternately, 2 or 3 or 4 of the 4 taken frames can be used for frame averaging. Each image is debayered, the frames are then aligned, then averaged.
- Any one of the 4 frames can be used singly as a "Plan B", or to paint over any areas with pixel shift artifacts.
The advantage of frame averaging is ultra low noise and a longer exposure effect, although there is in theory some risk of 4 snapshots (duplicate images) on moving stuff. However, Sony motion correction is supposed to deal with that excepting very small localized areas. So I deem frame averaging the ideal source image for painting in areas of motion, in most situations.
Below, 4 results frame one 4-shot pixel shift capture (4 frames as taken by the Sony A7R V).
