speedmaster20d wrote:
I did some digging in the facts, that means Sony's publications in peer reviewed journal, not internet rumors.
It turns out that Sony actually published the A1 sensor design and featured at ISSCC 2021 titled
ISSCC 2021: Sony 50.1MP Full-Frame Sensor with Sigma-Delta ADC and kTC Noise Reduction
Sony's technical paper reveals the facts and repeals fiction, rumors and speculations.
I attached the PDF down below,
what the paper reveals are several feature for the A1 sensor (to ones skilled in the art)
* column-parallel ΔΣ ADC
* pipelined S&H + kTC cancellation
* simultaneous multi-row pipeline stages with heavy parallel processing to achieve high FPS
However one not skilled in the art would easily confuse these two fundamental concepts as Dave Clark also pointed out earlier in this thread.
(1) charge transfer / pixel read (physical rolling shutter mechanism)
vs
(2) downstream conversion / ADC / processing pipeline
That distinction is crucial. The rolling shutter is result of (1) not (2)
what the paper reveals in horizontal scan diagram is consistent with row-by-row (or line-by-line) charge transfer with heavy downstream pipelining that was novel.
The converted photons are locked into electrical charge, and the charge transfer is row by row. but in parallel we have digital operation that can happen like below.
So while row N is being converted:
* row N+1 is being sampled
* row N−1 is in ADC stage
* row N−2 is in digital readout
the row N does not have to wait for row N-1 digital stages to finish, it just rolls on....
So as far as Sony A1 is concerned facts align and sensor architecture is consistent with the simple fan test, because of course there are no "alternative facts".
There is no evidence whatsoever to hint at multiple physically separated rows transferring charge simultaneously as a unit for A1 . That would require:
* multi-row global transfer gates
* or charge-domain batching memory per row group
and would be very unique. There is ZERO evidence of this and from a technical point of view it makes no sense (again to the skilled in the art).
and to understand what is really happening in cameras that show a certain different signature we need this kind of technical document to look at and should refrain from presenting speculations as facts.
good observations and data are facts, but hypothesis are not facts until proven beyond a reasonable doubt ...Show more →
That is an amazing find, thanks for sharing it, and thanks for applying your skill in the art in explaining it. I was 100% wrong on this and am deeply humbled. Apologies for my erroneous speculations.
speedmaster20d wrote:
the slope does not change in APS-C mode, it's the same. Slope is limited by sensor electronics not FoV or anything like that.
if you want to get same FoV in APS-C as FF you have to walk quite a bit back from the bird that will reduce the rotational speed as you pan from much farther away and makes the distortion less .... but no one would switch to APS-C and the walk back from the bird to end up with a low resolution image of a far bird.... doesn't makes sense really
It depends on what's being compared. People use crop mode because they can't fill the frame. If one is comparing 400mm at crop with 400mm at full frame, then yes, the slope is the same. If one is comparing 400mm at crop with 600mm at full frame because they don't want to afford 600mm, I think the slope is better on 400mm at crop.
