06-15-2011, 09:13 PM
[quote name='wim' timestamp='1308171429' post='9268']
Selective desaturation IOW.
[/quote]
No, NOT selective desaturation. Shrinking one of the colour channels, or expanding it, will not desaturate anything. Just make all 3 channels the same size again, which will mean the coloured edges will disappear, the CA induced sharpness will disappear and the contrast will recover.
You shrink or expand it from the image center.
The one you think was not directed at you, that one is about desaturating of colours, which is the less desirable way.
About you not needing an explanation, what you wrote about the CA needed some correcting. There is no La CA to be seen, not the blue part of the spectrum of the nose at least. All that is just PF. CA would show a totally different, and directional, character. The upper part of the instrument, if it was CA, would show on one side, seen from the center of the image, blue, and on the other side yellow lines around the dark parts. On the sides that are not on the direction towards the center of there image there would be no CA.
That is just the nature of LaCA. What we see is PF and some LoCA.
The colour of CA needed further explanation too, as yellow/blue is quite rare.
And yes, you are correct in understanding that with LaCA I am referring to Lateral Chromatic Aberration, as opposed to LoCA (longitudinal Chromatic Aberration)
Selective desaturation IOW.
[/quote]
No, NOT selective desaturation. Shrinking one of the colour channels, or expanding it, will not desaturate anything. Just make all 3 channels the same size again, which will mean the coloured edges will disappear, the CA induced sharpness will disappear and the contrast will recover.
You shrink or expand it from the image center.
The one you think was not directed at you, that one is about desaturating of colours, which is the less desirable way.
About you not needing an explanation, what you wrote about the CA needed some correcting. There is no La CA to be seen, not the blue part of the spectrum of the nose at least. All that is just PF. CA would show a totally different, and directional, character. The upper part of the instrument, if it was CA, would show on one side, seen from the center of the image, blue, and on the other side yellow lines around the dark parts. On the sides that are not on the direction towards the center of there image there would be no CA.
That is just the nature of LaCA. What we see is PF and some LoCA.
The colour of CA needed further explanation too, as yellow/blue is quite rare.
And yes, you are correct in understanding that with LaCA I am referring to Lateral Chromatic Aberration, as opposed to LoCA (longitudinal Chromatic Aberration)