A sample photo taken using the new Dynamic Pixel Shift Resolution mode. It can be difficult to put down a tripod in the busy Pike Place Market. Fortunately this new mode is meant to be used hand-held, capturing and combining four images for better detail and noise performance than a standalone image.
The Pentax K-1 II features a new Pixel Shift mode called 'Dynamic Pixel Shift Resolution' which doesn't require the use of a tripod. This hand-held mode works differently than traditional Pentax Pixel Shift mode, though it still combines up to a total of four images into one. We set out to give it a try and see how it stacks up.
Dynamic Pixel Shift Resolution explained
When using Dynamic Pixel Shift, image stabilization is switched on by default (a giveaway that it isn't doing single pixel shifts like its tripod-mounted counterpart) and the camera relies on the natural movement or shake of the photographer for four slightly different images. Stabilization remains on to ensure there is not too much of a framing difference between shots. The four files are then aligned and combined to produce one 'super resolution' image with increased detail, dynamic range and lower noise. Without getting into too much detail, sampling a scene multiple times with slight shifts to the image allows details to be localized with sub-pixel precision (since shifts are unlikely to be perfect multiples of one pixel).
Dynamic Pixel Shift Resolution is more like the multi-frame image stacking methods smartphones use
Calling this mode 'Pixel Shift' is a bit of a stretch, though. In fact, Dynamic Pixel Shift Resolution is likely more similar to the multi-frame image stacking methods employed by smartphone manufacturers. By contrast, traditional Pixel Shift uses the IS system to shift the sensor four times by exact one pixel increments, combining them into a file that not only increases sharpness and noise performance, but also effectively cancels out the Bayer color filter array. Each of the original pixel positions gets sampled by a red, a blue and two green pixels, something that doesn't appear to happen when using Dynamic Pixel Shift. This cancellation of the CFA eliminates color aliasing and artifacts, and removes the need to demosaic – a major advantage.
Comparing pixel shift modes
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The above widget shows the following:
Tripod PS (MC off): Standard Pixel Shift shot on a tripod with Motion Correction off
Handheld PS (handheld mode): Dynamic Pixel Shift shot handheld
Standard Electronic Shutter (No PS): Non-Pixel Shift shot
Tripod PS (handheld mode): Dynamic Pixel Shift shot on a tripod
When comparing the output of these two modes in our widget above (these are out-of-camera JPEGs), it's clear traditional Pixel Shift results in better detail capture than its hand-held counterpart – this is visible throughout our scene$(document). ready(function() { $("#icl-3967--848122397"). click(function() { ImageComparisonWidgetLink(3967); }); }). The former also displays no color moire$(document). ready(function() { $("#icl-3961--1555832239"). click(function() { ImageComparisonWidgetLink(3961); }); }), unlike hand-held mode. You can also see an example of this in our real world scene$(document). ready(function() { $("#icl-3962--421321298"). click(function() { ImageComparisonWidgetLink(3962); }); }).
Dynamic Pixel Shift Resolution can result in more detail capture than a standard image file [but] it comes at the cost of having random artifacts
And while Dynamic Pixel Shift Resolution can result in more detail capture than a standard image file, it comes at the cost of having random artifacts$(document). ready(function() { $("#icl-3960--2039500802"). click(function() { ImageComparisonWidgetLink(3960); }); }) in the image, manifesting as dotted artifacts in (seemingly) random portions of the image. You can also see these artifacts$(document). ready(function() { $("#icl-3963--1603032030"). click(function() { ImageComparisonWidgetLink(3963); }); }) in the tile work on the roof.
Takeaways and notes from the field
Note: Standard Pixel Shift mode with or without Motion Correction turned on (the former for this image) uses the electronic shutter, which can resulting in banding with artificial light sources, as seen above. This is due to the very slow shutter readout speed.
A few field notes before we wrap this up: When shooting in Dynamic Pixel Shift Resolution mode the camera uses the mechanical shutter, so we recommend using a high shutter speed to avoid any potential shutter shock or hand shake. By comparison, traditional Pixel Shift mode, whether using the motion correction option or not, relies on the electronic shutter. Under certain artificial lighting this can result in significant banding but, on the other hand, the electronic shutter guarantees sensor stability for the precise, one pixel increments needed to cancel out the effects of the Bayer CFA.
Ultimately Dynamic Pixel Shift Resolution mode can be useful for capturing more detailed images than a standard JPEG or DNG, but the potential for artifacts limits its appeal. And it simply cannot match the image quality output of the standard Pixel Shift mode, which we still recommend for the absolute best files out of the Pentax K-1 II.
Real world samples
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This gallery includes real world examples comparing The Pentax K-1 II's traditional Pixel Shift mode to the new hand-held Dynamic Pixel Shift Resolution as well as standard image files. The mode used is noted in the image captions.
Video Demo
The above demonstration shows the workflow and average in-camera processing time when using Dynamic Pixel Shift Resolution mode.
. dpreview.com2018-4-10 16:00