Iain West wrote:
I think the cells on the Foveion chip are arranged in a square
grid. Maybe that is why it is good a picking up vertical lines on
the chart.
I don't believe it will outperform a Bayer chip with the same pixel
count for a monohrome image of a normal subject.
Phil Askey wrote:
(It's Foveon not Faveon..)
Correct, as you point out the "purity of the line" is important and
has a direct effect on output resolution. Did you see the
resolution chart crop I posted in my X3 preview? The Foveon X3 is
capable of resolving more monochrome resolution than an identical
MP bayer chip. And just as importantly the resolution chart could
use red, blue, orange, purple or any coloured line and you'd get
the same resolution from the Foveon.. Try that with a mosaic chip.
-- Ulysses
Wrong. Bayer interpolation yields substantially less monochrome resolution than is implied by the pixel count. If a camera has 1200 sensors in the narrow dimension, and each sensor were directly linked to an output-pixel, you could resolve a maximum of 600 line pairs in that direction, if everything were aligned perfectly. In fact, with a bayer-type CCD, the best you can do is around 420 line pairs. That's because the luminance data is merged into 2x2 groups, and the output-pixels are each artificially correlated with each adjacent neighbor.
... The "purity of the Line" would be far superior with the Faveon though, because it can "resolve" perfect colour at eack "pixel" or "line element". In the bayer, you only have a red then blue then green / green pixel, so if it was a "red line" you'd miss resolution every 4 !! You can't MAKE UP what it was supposed to be !!!
I think your observation is correct. If a Foveon camera did not use
You're right that there's more overlap than we see with color filters. There's quite a bit of overlap in our own eyes too, but we seem to manage. It's a fair issue to raise, but my guess is that it won't be a very serious one in practice - but that's just a guess.
-------------------------------------------------------
We manage through post processing, taking lots of samples over time, and being tuned to largely ignore it when our eyes get it wrong (often). Colour is a compartively unimportant part of the human visual experience, and the contuned popularity of black and white photography is testament to this.
I agree that it's unlikely to be a serious problem, with respect to final images, even if it does actually mean that its colour reproduction is poor, for the reasons stated above. This product may very well still fail in the marketplace though if, as it seems, people are happy to percieve a certain level of edge artifacts as being benign, or even desirable, and the other manufactures carry on ramping up the pixel count whilst Foveon languishes at 3.5 megapixels.
This is misleading - Bayer sensors can actually recover image information quite close to their pixel resolution, as the example below (D30) illustrates:
Yes, it's truly terrible. I hide all my photos away in shame so that no-one can ever see them. The 19*13 inch prints on my wall that I tell people are from my D30 are actually secretly shot with medium format film. How could I have been so stupid as to buy one of those dreadful Bayer cameras?
Agreed.
I more or less agree with this too.
There will be edge artifacts and there will also be blurring of detail in varying degrees, depending upon the interpolation algorithm used.
Edge artifacts influence our percpeption of sharpness and detail. People like sharpened images because they have a very specific kind of edge artifact. I don't think corresponds well with Bayer interpolation artifacts or with the softening of detail that Bayer interpolation can produce.
If it produces good pictures, then this will go a long way towards overcoming these obstacles. However, I do agree in general that there will be many obstacles to overcome, some engineering, some marketing.
