Ender100@aol.com
Date: 08/14/03-12:00:44 PM Z
I'm going to take a stab at answering your question, but I am only guessing
at what the question is here. My apologies if I am not understanding you
correctly.
In the Curves Adjustment dialogue box you have two choices in how you make
curve adjustments. You can use percentages from 1%-100% or you can use levels
from 0-255. You can toggle this by CLICKING on the little gradient under
the chart. OPTION CLICKING on the chart itself toggles between two different
grid resolutions on the chart.
In either case, you are asked to establish the input value, or the tone that
you wish to modify along with your target value—the value you wish to change
that specific input value to. Thus you might have:
Input 10%
Output 22%,
Since you are working with an adjustment curve, and should this be a curve
with only this adjustment point on it, you would end up with all the tones at
10% converted to a darker tone, 22%—it will also darken all the other values of
the image somewhat, more so to those nearer 10% in value and less so for those
further away from 10%, such as 98%
Confused enough yet? If not, then continue reading....
As mentioned above, Photoshop has two systems to quantify tonal values. The
percentage (%) system and the levels system or a range of numbers 0-255.
In an 8 bit image, you have a possibility of 256 values of tonality, with 0
being black and 255 being white (255 +1 = 256, or 2 to the 8th power which is
where the term 8 bits comes from in a binary numbering system 1 would be
00000001, 2 would be 00000010. Unfortunately when Photoshop does values in this
manner, 0% is equal to white and 100% is equal to black. Using the "levels
method", the bigger the number, the lighter the value, thus 0 = black and 255 =
white. This is referring to the values you will see displayed in the INFO box
when you test with the eyedropper tool. (MAIN MENUBAR>WINDOWS>INFO)
Seriously, I hope this helps. Please excuse the text, it has been run
through a translator, Captain Video Decoder Ring, and a Speak & Spell.
Mark Nelson
In a message dated 8/12/03 11:59:32 AM, jusdado@teleline.es writes:
> If the "step tablet" it shows imput levels
> 5%=14
> 10%=27
> 20%=53
> 30%=79
> 40%=102
> 50%=129
> 60%=156
> 70%=180
> 80%=205
> 90%=230
> 95%=242
> reason the adjustment curves show other levels?
> 5%=13
> 10%=25
> 20%=51
> 30%=76
> 40%=102
> 50%=127
> 60%=153
> 70%=178
> 80%=204
> 90%=229
> 95%=242
> more contrast?
> can I increase the contrast using only output levels?
>
> Please answer
>
> Pardon for my English. Text translated by computer
>
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