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Author Topic: The A7R3 and the Result of Pixel-Shifting  (Read 143198 times)

Michael Erlewine

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Re: The A7R3 and the Result of Pixel-Shifting
« Reply #20 on: December 09, 2017, 11:14:00 AM »

I'm just wondering how you get natural subjects that aren't rocks to stay still for 100 low-ISO exposures without even moving a pixel, and how you get 100 images that line up perfectly at the pixel level despite shutter vibration.

Can the merged files be processed in other RAW converters (after all, they're still a kind of RAW file) or are you stuck using the Sony converter?

Big questions and not a lot of time to answer. In-studio is one point and being careful to isolate vibrations in the studio. As for lining up, you have to move carefully, etc.

As for raw converters, sure... these are just raw files.  No shutter vibration with that disabled.
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Michael Erlewine
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Michael Erlewine

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Re: The A7R3 and the Result of Pixel-Shifting
« Reply #21 on: December 09, 2017, 11:27:59 AM »

I need to understand better exaction what pixel-shifting does. As I understand it, what is improved is the color and any improvement in resolution/sharpness is the avoidance of artifacts made by the Bayer Interpolation. Is this correct?
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Michael Erlewine
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opgr

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Re: The A7R3 and the Result of Pixel-Shifting
« Reply #22 on: December 09, 2017, 03:15:41 PM »

I need to understand better exaction what pixel-shifting does. As I understand it, what is improved is the color and any improvement in resolution/sharpness is the avoidance of artifacts made by the Bayer Interpolation. Is this correct?

Correct.
(In case of the Olympus implementation you also get oversampling, but the available sensorsizes seem to limit the usefulness of that.)

In the Sony case currently it seems to create 4 RAW conversions which you somehow need to slam together. The net result would be less optimal than actually using the 4 files during demosaicing.

In your case, with manual focusing and stacking umpty files, you may wonder whether there is any gain relative to for example; stacking with automatic alignment in Affinity Photo. Taking say 10 shots with ever so slight movement and stack/align will likely result in a much better file than a stack of 4 pixelshifted files.


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Oscar

Ancient Tiger

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Re: The A7R3 and the Result of Pixel-Shifting
« Reply #23 on: December 10, 2017, 04:32:52 PM »

I'm just wondering how you get natural subjects that aren't rocks to stay still for 100 low-ISO exposures without even moving a pixel, and how you get 100 images that line up perfectly at the pixel level despite shutter vibration.

Can the merged files be processed in other RAW converters (after all, they're still a kind of RAW file) or are you stuck using the Sony converter?
Iridient Developer 3.2.1 handles the raw files and gives you a choice whether to open them as 4 individual raw files (.ARW) or as one combined file (.ARQ).
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shadowblade

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Re: The A7R3 and the Result of Pixel-Shifting
« Reply #24 on: December 10, 2017, 09:23:05 PM »

Iridient Developer 3.2.1 handles the raw files and gives you a choice whether to open them as 4 individual raw files (.ARW) or as one combined file (.ARQ).

Great.

Can the merged RAWs be exported as a single ARQ file, then opened in a program like C1 or DxO Optics? Or are the Sony program and Iridient the only programs which recognise the ARQ format?

The reason I'm asking is because, for the painting-over-motion-blur technique to work properly (making pixel shift usable for landscapes, where you can expect some subtle movement), you'd need to process the ARQ and ARW files identically - doubly so if you're also using some sort of exposure blending or HDR technique. I'd much rather process the single RAW files using the tools and algorithms of C1 or DxO than have to do so using a less-powerful, less-flexible program, just to keep it the same as the merged file.
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Ancient Tiger

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Re: The A7R3 and the Result of Pixel-Shifting
« Reply #25 on: December 11, 2017, 02:08:00 AM »

Great.

Can the merged RAWs be exported as a single ARQ file, then opened in a program like C1 or DxO Optics? Or are the Sony program and Iridient the only programs which recognise the ARQ format?

The reason I'm asking is because, for the painting-over-motion-blur technique to work properly (making pixel shift usable for landscapes, where you can expect some subtle movement), you'd need to process the ARQ and ARW files identically - doubly so if you're also using some sort of exposure blending or HDR technique. I'd much rather process the single RAW files using the tools and algorithms of C1 or DxO than have to do so using a less-powerful, less-flexible program, just to keep it the same as the merged file.
DxO does not support the A7rIII as yet. C1 opens .ARW files but as yet does not recognise .ARQ files (even C1 version 11).
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lightskyland

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Re: The A7R3 and the Result of Pixel-Shifting
« Reply #26 on: December 11, 2017, 02:46:28 AM »

Pixel-shift uses E-shutter, so no shutter vibration at all.
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