QTR cool curve creation help needed

[JohnAONeill]

Hey Guys

Having spent some time now with QTR I have just completed my first custom curve for the MK LK and LLK inks on my 7900 printer. I've tested my new curve and the linearity is very good and prints look great. Of course the Epson black inks are very warm so I need to create a cool curve with just enough cool tone to neutralise the warm inks. I just cannot figure out a few things and so I'm hoping someone here can help. Below are some questions I have;

1. When creating a cool curve is it a good idea to start off with a copy of the custom made warm curve settings and then add in the cyan and magenta? Or should the black and grey settings be set to a lower value than the initial warm curve?

2. Can anyone offer a simple step by step approach to making a cool curve? I'm finding the supplied documentation and online tutorials confusing for this part of the curve creating process.


Hope someone with QTR experience can help out.

Best regards
John

[TylerB]

yes in terms of your density and limits for the K and light K inks that's fine, but you'll of course have to redo linearization for the new one with added cool inks. For toning curves it's usually best to make them a little too colorful, so you can blend precisely to taste when you print, changing that curve's percentage to your existing K inks only curve, to very subtle degrees, even splitting between Highlights, mids, and shadows..
Hope that made sense. You may get more working opinions here-
http://tech.groups.yahoo.com/group/QuadtoneRIP/
Tyler

[JohnAONeill]

yes in terms of your density and limits for the K and light K inks that's fine, but you'll of course have to redo linearization for the new one with added cool inks. For toning curves it's usually best to make them a little too colorful, so you can blend precisely to taste when you print, changing that curve's percentage to your existing K inks only curve, to very subtle degrees, even splitting between Highlights, mids, and shadows..
Hope that made sense. You may get more working opinions here-
http://tech.groups.yahoo.com/group/QuadtoneRIP/
Tyler

Hi Tyler

Many Thanks for your help. You preempted my next question about toning. I noticed when experimenting today that toning curves can sometimes neutralize some tones whilst adding a slight cast to others. I'll have to experiment a bit more with the split toning sliders. Or do you think this is a problem with ink limits in the toner channels?

Regards
John

[TylerB]

there are ways to customize the toner ink curve alone. But there is a lot of trial and error, when another another paper or other display light you may want it changed on a given image. My conclusion was to put more than enough color ink in any given curve (other than the K only curve) than I would generally want, then use the sliders to tweak through the scale on a given image.
It's a brilliant system, but one thing it doesn't do is help you find dead neutral as a starting point. But we never had that in the darkroom either with our bromides and chlorobromides and paper developers and additives and toners.. it was all visual and talent. Caponigro.. for example...

There are more sophisticated QTR users than I, so looking for other input would be helpful. I play with QTR when I need to, but primarily use Ergosoft for that work.
Tyler

[JohnAONeill]

there are ways to customize the toner ink curve alone. But there is a lot of trial and error, when another another paper or other display light you may want it changed on a given image. My conclusion was to put more than enough color ink in any given curve (other than the K only curve) than I would generally want, then use the sliders to tweak through the scale on a given image.
It's a brilliant system, but one thing it doesn't do is help you find dead neutral as a starting point. But we never had that in the darkroom either with our bromides and chlorobromides and paper developers and additives and toners.. it was all visual and talent. Caponigro.. for example...

There are more sophisticated QTR users than I, so looking for other input would be helpful. I play with QTR when I need to, but primarily use Ergosoft for that work.
Tyler


Hi Tyler

Sorry for my delayed response I have been away from LuLa trying to catch up on some "real work"!!
After spending almost a week trying to fine tune QTR to get neutral prints I have finally started to get some really nice prints :-) I'm still not quite sure how I got there through as there were so many iterations I lost track somewhere along the way. I think your advise on using the sliders to balance out the neutrality is sound. I'm wondering if anyone else can shed some light on a good workflow for creating a cool curve. I'd like to profile some additional papers so any shortcuts would be good to hear! Anyone else like to contribute?

Best regards
John