Hi Sandy
--
Well that was a weird one. I tried the numbers you have and they worked just fine, but when
put all together they didn't work. After staring at it a while I suddenly saw it.
The double quotes on the density line are not regular double quotes. They are "smart" quotes or
maybe better described as dumb ones. If you just retype both it works just fine. Very, very subtle.
Old way:
LINEARIZE=“1.37 1.21 1.09 1.02 .95 .87 .82 .77 .72 .65 .60 .55 .50 .45 .41 .37 .33 .27 .16 .07 .00”
Fixed way:
LINEARIZE="1.37 1.21 1.09 1.02 .95 .87 .82 .77 .72 .65 .60 .55 .50 .45 .41 .37 .33 .27 .16 .07 .00"
BTW -- I also notice in the 2 files one is missing the .07 value. ?? See:
#LINEARIZE=“1.37 1.21 1.09 1.02 .95 .87 .82 .77 .72 .65 .60 .55 .50 .45 .41 .37 .33 .27 .16 .00”
One comment: if you have a device that gives the L-values they in general will be more accurate.
Notice that all the L-values have 4 significant digit, whereas the densities barely have 2 digits
at the white end. Of course if you read density and convert to L you'll not really be any better.
Best,
Roy
On Mon, Jul 24, 2017 at 4:14 PM, sanking@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote:
Hi Roy,
My assumption was that the density numbers should be entered as you note and that a correction curve with density numbers starting with the high density log measurements should be similar to a correction curve with lab values, inverted.
But sometimes this does not happen. I am including the .txt files of two profiles, one linearized with a spectro, the other with log density entries. When I run Install the one with lab values creates a good .quad file, but the one with density readings does not. If the lowest density readings is 0.00 the .quad files that is created is a straight line, similar to the original file with no linearization. If I enter a low density reading of 0.01, the .quad file is not created at all?
I have double checked my readings and entries and they look OK. Would appreciate your advice as to what I might be doing wrong.
Sandy
1. Linearize with lab values.
#PRINTER=Quad4880
#CURVE_NAME= Carbon100-230 #Based on Carbon Tissue #230, 14 grams of Black Cat Ink + 2 grams of Mixol #11, with tissue coated to a wet height of 0.9mm.
#Profile when printing a step wedge gives a DR (density range) of approximately log 2.05.
#With Tissue #230 sensitize with a 4% potassium dichromate solution, diluted 1+1 with acetone, approximately 10 ml per 8X10 sheet, applied in two coatings with a roller. 350 ULF units.
GRAPH_CURVE=YES
N_OF_INKS=8
DEFAULT_INK_LIMIT=100
LIMIT_K=25
LIMIT_C=1
LIMIT_M=1
LIMIT_Y=25
LIMIT_LC=1
LIMIT_LM=1
LIMIT_LK=50
LIMIT_LLK=1
GRAY_HIGHLIGHT=4
GRAY_SHADOW=4
GRAY_GAMMA= 1
CURVE_K= "0;0 100;100"
COPY_CURVE_C=K
COPY_CURVE_M=K
COPY_CURVE_Y=K
COPY_CURVE_LC=K
COPY_CURVE_LM=K
COPY_CURVE_LK=K
COPY_CURVE_LLK=K
LINEARIZE="25.36 30.5 34.58 37.29 40.37 43.36 45.96 48.44 50.99 53.52 56.41 59.24 61.36 64.34 67.25 69.62 72.48 76.31 83.55 89.9 96.74"
#LINEARIZE=“1.37 1.21 1.09 1.02 .95 .87 .82 .77 .72 .65 .60 .55 .50 .45 .41 .37 .33 .27 .16 .00”
2. Linearize with log density readings.
#PRINTER=Quad4880
#CURVE_NAME= Carbon100-230 #Based on Carbon Tissue #230, 14 grams of Black Cat Ink + 2 grams of Mixol #11, with tissue coated to a wet height of 0.9mm.
#Profile when printing a step wedge gives a DR (density range) of approximately log 2.05.
#With Tissue #230 sensitize with a 4% potassium dichromate solution, diluted 1+1 with acetone, approximately 10 ml per 8X10 sheet, applied in two coatings with a roller. 350 ULF units.
GRAPH_CURVE=YES
N_OF_INKS=8
DEFAULT_INK_LIMIT=100
LIMIT_K=25
LIMIT_C=1
LIMIT_M=1
LIMIT_Y=25
LIMIT_LC=1
LIMIT_LM=1
LIMIT_LK=50
LIMIT_LLK=1
GRAY_HIGHLIGHT=4
GRAY_SHADOW=4
GRAY_GAMMA= 1
CURVE_K= "0;0 100;100"
COPY_CURVE_C=K
COPY_CURVE_M=K
COPY_CURVE_Y=K
COPY_CURVE_LC=K
COPY_CURVE_LM=K
COPY_CURVE_LK=K
COPY_CURVE_LLK=K
#LINEARIZE="25.36 30.5 34.58 37.29 40.37 43.36 45.96 48.44 50.99 53.52 56.41 59.24 61.36 64.34 67.25 69.62 72.48 76.31 83.55 89.9 96.74"
LINEARIZE=“1.37 1.21 1.09 1.02 .95 .87 .82 .77 .72 .65 .60 .55 .50 .45 .41 .37 .33 .27 .16 .07 .00”