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k1 pixel shift - can you see the different?

Started 4 months ago | Discussions thread
JeremieB Senior Member • Posts: 2,041
Re: k1 pixel shift - can you see the different?
4

flektogon wrote:

MaKeR wrote:

I can see the difference, and it's clear that *89.PEF is the Pixel Shift image. The other one is less sharp and has false detail.

Yes, this explanation is fully supported by the sampling theorem! Any good lens like mentioned Pentax 100/2.8 Macro can project as a maximum around 35 mega-details/points on a full frame sensor. So a camera with 36 Mp is (theoretically) capable register all those details. However, every "extra" detail above 18Mp will be accompanied with another, false detail.

I'm sorry but that's a slightly misleading way to describe the Nyquist theorem

First it should be 9Mp - sampling theorem applies on both rows AND columns.

Then it's wrong to talk about MP and details, the theorem applies on frequencies.

When we shoot with the simulated AA filter of Pentax, the sensor still scans 36MP but there's no moiré, why ? Because details are not MP

With the pixel shift your camera behaves like having a 144Mp sensor, so it will be (again, theoretically ) capable of registering 72 mega-details without any aliasing. Well, there are no lenses capable delivering so much details, but still.

So, if looking into difference between a single and shifted image, don't look at the amount of details, rather at a lack of false details (moire).

 JeremieB's gear list:JeremieB's gear list
Pentax K-70 Pentax K-3 Mark III Pentax smc FA 50mm F1.4 Pentax smc DA 18-55mm F3.5-5.6 AL Pentax smc D-FA 100mm F2.8 Macro WR +9 more
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