10-05-2010, 11:01 AM
[quote name='Brightcolours' timestamp='1286272202' post='3492']
Nonsense, it shows that detail is in luminance (dark and light differences). That black and white are extremes in luminance information is a given.
Now, instead of digging your heels in the sand, actually LOOK at the samples.
The 20 dollar bill. Is it black and white? Of course not. It is different gradations of green (not pure green, check that in PS if you like). We see a big increase in detail. The cable next to it. Metal strands against a saturated blue background. Big increase in detail. The brass screw part of the cable, it is a yellow in different shades. Big increase in "sharpness".
The dollar bill "head", Has a light blue bird figure next to it. Big increase in the feather pattern "sharpness".
The face itself, only browns (so all colours in different gradations). Clearly has much more detail/sharpness.
The car's dials. The red hans clearly are much "sharper", we see very clear aliasing stair stepping in them. You refuse to see that.
The chrome ball in the lever. It shows more "definition" everywhere, including where we have blue, red. The steering wheel also has all colour channels in different values, it is not black and white at all. Yet we see the shades of brown. blue clearly and see detail increase in equal amounts.
The brass key. The brown fake wood.
It all shows the same increase in sharpness, in aliasing, in stair stepping. That you want to keep saying it is only in black and white areas is your choice, it does not make it true.
Yes, detail is in luminance information.
[/quote]
Ok. I guess it will be easier if I go step by step:
1. "B/W sections" - my bad, what I was actually trying to say, is that those sections demonstrate luminance only based details, with chroma having little or no effect on the image contrast. Now it sounds more or less right.
2. So just to reiterate - according to you, only luminance (dark and light difference) creates detail, while chroma (wavelength difference) does not, correct?
3. I'm looking into these images again, and what I can see quite clearly that if there's a substantial change in brightness but not in colour (i.e. shades of green, brown, whatever), it gets sharpened quite neatly with just a minor increase in aliasing "stepping" - dollar bill, digits on a speedometer, etc. Except maybe the leather steering wheel, which looks like a perfect "snap to grid" example to me.
However all details created by a strong change in colour, e.g. edges of a speedometer needle, red belt, brass screw and blue keyfob, all red reflections on chrome surfaces, metal strands against blue background, etc. show interpolation artifacts and much larger "stepping". Please don't tell me you don't see it :-)
BTW, [quote] The car's dials. The red hans clearly are much "sharper", we see very clear aliasing stair stepping in them. You refuse to see that. [unquote] - that's my point exactly!
All in all, it seems that this dispute successfully got itself into a deadlock. It would be really helpful to get some raw files both from Sigma and filter-less Bayer, unfortunately I can't find it online. Genotypewriter - you mentioned that you have a 50D with AA filter removed, would you mind sharing with some raw files please?
Nonsense, it shows that detail is in luminance (dark and light differences). That black and white are extremes in luminance information is a given.
Now, instead of digging your heels in the sand, actually LOOK at the samples.
The 20 dollar bill. Is it black and white? Of course not. It is different gradations of green (not pure green, check that in PS if you like). We see a big increase in detail. The cable next to it. Metal strands against a saturated blue background. Big increase in detail. The brass screw part of the cable, it is a yellow in different shades. Big increase in "sharpness".
The dollar bill "head", Has a light blue bird figure next to it. Big increase in the feather pattern "sharpness".
The face itself, only browns (so all colours in different gradations). Clearly has much more detail/sharpness.
The car's dials. The red hans clearly are much "sharper", we see very clear aliasing stair stepping in them. You refuse to see that.
The chrome ball in the lever. It shows more "definition" everywhere, including where we have blue, red. The steering wheel also has all colour channels in different values, it is not black and white at all. Yet we see the shades of brown. blue clearly and see detail increase in equal amounts.
The brass key. The brown fake wood.
It all shows the same increase in sharpness, in aliasing, in stair stepping. That you want to keep saying it is only in black and white areas is your choice, it does not make it true.
Yes, detail is in luminance information.
[/quote]
Ok. I guess it will be easier if I go step by step:
1. "B/W sections" - my bad, what I was actually trying to say, is that those sections demonstrate luminance only based details, with chroma having little or no effect on the image contrast. Now it sounds more or less right.
2. So just to reiterate - according to you, only luminance (dark and light difference) creates detail, while chroma (wavelength difference) does not, correct?
3. I'm looking into these images again, and what I can see quite clearly that if there's a substantial change in brightness but not in colour (i.e. shades of green, brown, whatever), it gets sharpened quite neatly with just a minor increase in aliasing "stepping" - dollar bill, digits on a speedometer, etc. Except maybe the leather steering wheel, which looks like a perfect "snap to grid" example to me.
However all details created by a strong change in colour, e.g. edges of a speedometer needle, red belt, brass screw and blue keyfob, all red reflections on chrome surfaces, metal strands against blue background, etc. show interpolation artifacts and much larger "stepping". Please don't tell me you don't see it :-)
BTW, [quote] The car's dials. The red hans clearly are much "sharper", we see very clear aliasing stair stepping in them. You refuse to see that. [unquote] - that's my point exactly!
All in all, it seems that this dispute successfully got itself into a deadlock. It would be really helpful to get some raw files both from Sigma and filter-less Bayer, unfortunately I can't find it online. Genotypewriter - you mentioned that you have a 50D with AA filter removed, would you mind sharing with some raw files please?