Why do Hi ISO pictures lose saturation of color?
Mar 28, 2017 14:16:27 #
selmslie wrote:
... Feel free to supply your own illustration and don't forget to "store original" so we can verify your claims.
Here is another sample with a gradient that runs from saturated red to black.
At what point does the redness go away? When it does, the question of saturation becomes moot.
Mar 28, 2017 14:20:11 #
Same thing with a yellow gradient.
Here there is no question that the brightest yellow is brighter than the brightest red in the previous post.
Here there is no question that the brightest yellow is brighter than the brightest red in the previous post.
Mar 28, 2017 14:58:32 #
While you are pondering my samples, take a look at this.
Here is the B&W conversion with equal adjustment (no bias) to the intensity of the red, green or blue channels.
A picture is worth a thousand words [or numbers].
Here is the B&W conversion with equal adjustment (no bias) to the intensity of the red, green or blue channels.
A picture is worth a thousand words [or numbers].
Mar 28, 2017 15:07:48 #
selmslie wrote:
According to whom? You?
Apaflo wrote:
Brightness is the maximum value of any of the three RGB triplet. ...
According to whom? You?
According to virtually every authority on this topic.
That simply is the way an HSV/HSB value for the brightness scalar is calculated. Once again here are formulas to calculate Brightness and Saturation from an RGB triplet.
Determine M and m, where
M = max{R, G, B}
m = min{R, G, B}
If M = 0, then both Brightness and Saturation are 0.
If M is greater than 0,
Brightness = M/255
Saturation = 1 - m/M
A few references:
https://en.wikipedia.org/wiki/HSL_and_HSV
http://www.rapidtables.com/convert/color/rgb-to-hsv.htm
http://math.stackexchange.com/questions/556341/rgb-to-hsv-color-conversion-algorithm
http://www.had2know.com/technology/hsv-rgb-conversion-formula-calculator.html
https://axonflux.com/handy-rgb-to-hsl-and-rgb-to-hsv-color-model-c
https://www.mathworks.com/help/matlab/ref/rgb2hsv.html
http://www.easyrgb.com/index.php?X=MATH&H=20#text20
http://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl/
https://www5.in.tum.de/lehre/vorlesungen/graphik/info/csc/COL_25.htm
http://www.poynton.com/PDFs/coloureq.pdf
Your posted examples do not even address the point, so the question is what do you think they showed?
Mar 28, 2017 15:11:54 #
selmslie wrote:
Here there is no question that the brightest yellow is brighter than the brightest red in the previous post.
There is serious question about such a claim!
You are not demonstrating anything other than a lack of knowledge about color calculations and measurements.
Mar 28, 2017 16:28:17 #
Apaflo wrote:
There is serious question about such a claim!
You are not demonstrating anything other than a lack of knowledge about color calculations and measurements.
You are not demonstrating anything other than a lack of knowledge about color calculations and measurements.
Photography is not about calculations and numbers. It about visible images.
Don't you know why people take pictures? It's to produce images, not to provide fodder for their computer.
If you can't produce visible evidence to back up your words, numbers and calculations then they are all worthless BS and you don't understand photography.
Until you can produce a decent visible example you are only flapping your arms and lips ineffectually.
So what is your problem producing visible evidence? Do you not know how, you can't because it would show you are wrong or are you just too lazy?
Leave these topics to real photographers. You are a waste of our time.
Mar 28, 2017 17:10:51 #
Apaflo wrote:
... Your posted examples do not even address the point, so the question is what do you think they showed?
They show that you don't know what you are talking about - endlessly.
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