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Is it the end of SA mount ???
#9
Correction: you don't need an AA-filter once you exceed the diffraction softening effects of the optics. Higher resolutions do not change Nyquist-Shannon.

(09-25-2018, 11:46 AM)JJ_SO Wrote:
(09-25-2018, 11:21 AM)Brightcolours Wrote: It is not opinion, it is fact. No AA-filter means fake detail and false sharpness. Foveon sensors do not have AA-filters. Ergo: fake detail and false sharpness. The bullshit crap from Sigma/Foveon about how they do not need AA-filters because of whatever is just that, bullshit crap.

Calling Nyquist-Shannon sampling theorem "bullshit" is rich, it is a very well established theorem. That some people get impressed by the fake sharpness due to aliasing, is fine.

Don't call your opinion fact: The picture recording technique of a sensor is a rasterizing of reality, analogue structures which become transferred into 0 and 1, rather simplified. Sigma/Foveon does not put another step (actullay two extra artifical steps, softening and re-sharpening) in between, which most Bayer sensors have just to make the green blue green red pattern less visible.

The only faking part is the Bayer aspect, while Foveon takes reality as real as possible (for a digital sensor).

I also don't know any of Terry Pratchett's picture painting gnomes, who really paint - all printers use the same nozzle patterns and the ink just flows together, no matter if you put a fake mushy AntiAliasing filter in between or not.

You constantly look through a softented array of pixels and call the lack of the softening part "fake sharpness", that's rather bold and pretty stupid - on the contrary, there's no need to add extra sharpness like all the RAW converters do for Bayer pattern pictures. the softening AA filter leads to two extra loops - make the pixel structure melt and then re-sharpen it again, to regain some details. That's the real fake part! Not the Foveon sensor.

And as for Nyquist-Shannon sampling theorem: That was articulated decades ago the development of Foveon sensors. Your choice to stick with stone age theorems which adequately described a pattern with only two dimensions - because there was no third available at the time of the postulation.

(09-25-2018, 11:24 AM)davidmanze Wrote: The key to the modern day photographic industry is good sales.......that quite simply excludes the foveon sensor!

If there were no Foveon sensors around, the Sigma Art lenses would not have become such outstanding optical instruments.

What I wrote is fact, what you bring against that is just ill-informed opinion.
The world does NOT magically align to a grid of square pixels. The grid of square pixels is exactly what causes aliases. It is exactly the reason you do need an AA-filter to avoid fake sharpness/false detail.

Bayer CFA has NOTHING to do with this, nothing to do with aliasing.
Besides that, the current Sigma foveon sensors have LESS resolution in two channels than you claim. You need the same demosaicing to get to converted pixels as you do with Bayer CFA or what Fuji has to do with its CFA. 

What you write about Nyquist-Shannon shows a total no-understanding about sampling, about what the theorem is about and why it does apply, also with Foveon sensors. No idea why you feel that Sigma somehow gives 3D images, and no idea why you think Nyquist-Shannon would not apply to 3D, anyway.

On printers: not every printer uses the same dithering algorithms. And the ink does not flow together, you should look at the printed results up close sometime. The dithering is done to simulate different colours, not to obfuscate pixels. You can still see pixels and aliasing, "flowing ink" does not blur that all together. Maybe if you use water to muddy the printed results?
  


Messages In This Thread
Is it the end of SA mount ??? - by toni-a - 09-25-2018, 07:28 AM
RE: Is it the end of SA mount ??? - by JJ_SO - 09-25-2018, 08:42 AM
RE: Is it the end of SA mount ??? - by JJ_SO - 09-25-2018, 11:46 AM
RE: Is it the end of SA mount ??? - by davidmanze - 09-25-2018, 11:24 AM
RE: Is it the end of SA mount ??? - by Klaus - 09-25-2018, 12:19 PM
RE: Is it the end of SA mount ??? - by JJ_SO - 09-25-2018, 12:28 PM
RE: Is it the end of SA mount ??? - by Brightcolours - 09-25-2018, 12:30 PM
RE: Is it the end of SA mount ??? - by JJ_SO - 09-25-2018, 12:40 PM
RE: Is it the end of SA mount ??? - by Rover - 09-25-2018, 12:53 PM
RE: Is it the end of SA mount ??? - by JJ_SO - 09-25-2018, 01:54 PM
RE: Is it the end of SA mount ??? - by JJ_SO - 09-25-2018, 07:56 PM
RE: Is it the end of SA mount ??? - by forum - 09-26-2018, 03:05 AM
RE: Is it the end of SA mount ??? - by Rover - 09-26-2018, 01:15 PM
RE: Is it the end of SA mount ??? - by toni-a - 09-26-2018, 12:28 PM

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