Hi Everyone,
Trying to figure out the process of making a digital negative with QTR
I am looking at what was written in the past by Sandy and Mike about using a single gray system. I am using a Epson 7880 on a Mac and printing mostly Palladium prints. I am using florescent BLB bulbs in a UV box. I am using Fixxons and Hahnemuhle Platinum Rag. I am using 18 drops FO + 18 drops PD 2 drops Tween 20 and 1 drop Na2 2.5% I keep the paper overnight in a humidity chamber at 45% humidity at around 70-74 degrees. I coat it and let is set for 4-5 minutes. I don’t dry it with any fan after.
Step 1: I used a 31 step Tablet from Mark Nelson and figured that my max print time for blacks. 7 minutes gave me blacks merged from step 1-3. I made my printing time 4 minutes.
Step 2: I printed the inktone separation test in Quadtone RIP Calibration mode (per Clays instructions) I found the K ink becomes pure white at 80%. I compared the LK strip to the K strip and found that 85% LK = 50%K. Yellow is 80% pure white and the LLK 100% LLK = 25%K. Again following what Clay wrote a while back
Where I get confused now is that if I look at what Sandy and John wrote in the newly released and wonderful Carbon book, I don’t see how you get the limits of the inks. If I go by Clays method, I get:
DEFAULT_INK_LIMIT=100
BOOST_K=0
LIMIT_K=80
LIMIT_C=1
LIMIT_M=1
LIMIT_Y=12
LIMIT_LC=1
LIMIT_LM=1
LIMIT_LK=85
LIMIT_LLK=100
N_OF_GRAY_PARTS=3
GRAY_INK_1=K
GRAY_VAL_1=100
GRAY_INK_2=LK
GRAY_VAL_2=50
GRAY_INK_3=LLK
GRAY_VAL_3=20
When I look at Sandy’s I see
DEFAULT_INK_LIMIT=55
LIMIT_K=25
LIMIT_C=25
LIMIT_M=1
LIMIT_Y=25
LIMIT_LC=1
LIMIT_LM=1
LIMIT_LK=40
LIMIT_LLK=1
How do you get those values from the inktone separation test? Do you enter the info for density or is that replaced with the DEFAULT_INK_LIMIT=55
I tried printing out the profile like this:
GRAPH_CURVE=YES
N_OF_INKS=8
DEFAULT_INK_LIMIT=55
LIMIT_K=25
LIMIT_C=25
LIMIT_M=1
LIMIT_Y=25
LIMIT_LC=1
LIMIT_LM=1
LIMIT_LK=40
LIMIT_LLK=1
GRAY_HIGHLIGHT=4
GRAY_SHADOW=4
GRAY_GAMMA= 0.7
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
It installed but I got an error about the curve. When I printed it, the ink was dripping off the negative.
The other problem I had was when I tried to go to the next step of building the curve. I tried the Build QTR Curve.jsx with Photoshop CC 2017 and I got an error about a command no longer valid and the action stopped. I also have a Spider 4 spectrometer and was able to do it that way using the B&W mastery excel sheet.
I know, lots of questions, but I have done about 30 prints already trying to get this process down.
Thanks,
Greg