k1 pixel shift - can you see the different?

flektogon wrote:

JeremieB wrote:

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).

Don't be sorry, I am fully aware that what I wrote was (a little bit ) misleading. Of course, for and a 100% reconstruction of the sampled original and avoiding any aliasing, the sampling frequencies in both directions have to be 2 times greater than the highest frequency component of the original (i.e. the maximum lp/mm resolution of a lens). But practically this is not used in the digital photography. If it was, then for example, such a camera like Pentax K-1 with a 36 Mp sensor with (fully) engaged AA filter would not deliver more than 9 mega details. What we see, all digital cameras, even those with built-in AA filters, deliver something like 40%-60% of their sensor resolution. Look for example at the DXOMark lens reviews. Well, I just simplified it to 50% .

I though k1 has no AA?