QTR Which Numbers to Use

[Patrick Kolb]

I have just started QTR and after setting things up and getting started with trying to get decent looking test stripes, I have noticed that the manual for the Epson 3800 and using OHP material has a different set of numbers for the curve than the recent post by Ron. For example in the manual it lists the DEFAULT_INK_LIMIT=100 and states this is a constant, while the posted new curve lists it at 18. Also, the manual lists the LIMITS for K,C,M,Y at 18 and the new curve leaves them blank. I know I must be doing something wrong, because my testing has yielded nothing useable so far. I have only been at this for two days, so any information would be helpful.

 

[Ron-san]

I have just started QTR and after setting things up and getting started with trying to get decent looking test stripes, I have noticed that the manual for the Epson 3800 and using OHP material has a different set of numbers for the curve than the recent post by Ron. For example in the manual it lists the DEFAULT_INK_LIMIT=100 and states this is a constant, while the posted new curve lists it at 18. Also, the manual lists the LIMITS for K,C,M,Y at 18 and the new curve leaves them blank. I know I must be doing something wrong, because my testing has yielded nothing useable so far. I have only been at this for two days, so any information would be helpful.

Patrick-- The confusion arises because there are at least two ways to use the default ink limit.
One way is to set the Default Ink Limit to a number (let's say 25 as an example), then leave the Limit blank for various individual inks. If you do that, each of the individual inks with a blank number will be controlled by the Default Ink Limit (25 in this example). I used to do things that way.
But in Version 2of the QTR Manual I decided to do things differently in an attempt to reduce the number of variables that needed to be kept track of. So, in this newer approach the Default Ink Limit is set at its maximum of 100 and is never changed. Each individual ink is specified by its own number (I try to use the same number for all the dark inks and another number for all the light inks, again trying to keep things simple). In this newer approach I do not leave any of the individual ink limits blank or they would automatically shoot up to 100 ( the setting of the Default Ink Limit).

Does that clear things up? Good luck. Ron Reeder

 

[Patrick Kolb]

Thank you Ron, that does clear things up. But working with this it seems that test strips are way to dense for me. So I reduced both the ink limit and the boost and reached a point were everything was muddy. By then splitting the difference of the two, I tried again and then split the difference and tried again, and so on. I am still not there, but it seems that the higher boost number helps in obtaining paper white and the dark ink limit will help me get to the steps in the high values of the print. I also found that increasing the numbers for the lighter inks, increased the separation in the low values, just as you said in the manual. I ran out of film yesterday, but later today I will be trying a new curve with a boost of 20 and limits of 12 for the dark colors and finally limits of 35 for the light colors. Does this sound like it would work, or have I gotten derailed somewhere. I am making pure palladium prints on Weston paper.

 

[Ron-san]

Thank you Ron, that does clear things up. But working with this it seems that test strips are way to dense for me. So I reduced both the ink limit and the boost and reached a point were everything was muddy. By then splitting the difference of the two, I tried again and then split the difference and tried again, and so on. I am still not there, but it seems that the higher boost number helps in obtaining paper white and the dark ink limit will help me get to the steps in the high values of the print. I also found that increasing the numbers for the lighter inks, increased the separation in the low values, just as you said in the manual. I ran out of film yesterday, but later today I will be trying a new curve with a boost of 20 and limits of 12 for the dark colors and finally limits of 35 for the light colors. Does this sound like it would work, or have I gotten derailed somewhere. I am making pure palladium prints on Weston paper.

Patrick--

My own QTR profile for the 3800 and palladium printing uses Dark ink limits of 18, boost K of 25, LM and LC at 30, LK at 35 and LLK is at 0. Sounds like your numbers are not too far from that. There could easily be differences in the way you and I print that would make you come up with different numbers than I use. Hang in there. Ron Reeder