QTR-Quadtone RIP

Clay,

This is becoming a very interesting and informative discussion. I've used PDN and Ron Reeder's QTR method and am sold on QTR as it as good or better and is not patented. I'm curious about your thoughts via Ron's method. He mixes equal parts black, cyan, magenta and yellow in his profile with a black boost. He does this to smooth out continuous tones. But according to your analysis this would have the opposite effect because it mixes high UV blocking (black and yellow) with low UV blocking (cyan and magenta). I know in a previous post you indicated that you had many conversations with Ron about QTR. I'd be interested in your thoughts about this. 

Thanks

Alan

On Jan 18, 2012, at 9:22 AM, clayharmon47 wrote:

> Mark's PDN system is perhaps the only comprehensive 'turnkey' solution to making digital negatives. All the others have some DIY aspects to them. 
> 
> I've been doing digital negatives since 2001. I first started out with Dan Burkholder's approach using imagesetter negatives and later used his colorized inkjet negatives. I even created my own colorized negative approach that you can find on www.alternativephotography.com ( although I now think QTR is a vastly superior approach).
> 
> When Mark first came out with PDN around 2006, I bit the bullet and paid for a license, even with the restrictions involved, thinking I could at least use it for my own work. I had just purchased a new 7800 printer and thought it would be straightforward to create a digital negative workflow. It was straightforward, but I ran headlong into a few problems that I think are under-appreciated. 
> 
> First and foremost, the approach depends on using the out-of-the-box printer drivers for printing. The thing is, Epson (and others) write driver software to create their smooth tonal transitions based on visual density from reflective substrates. Digital negatives depend on transmission densities through transmissive substrates, and UV light sensitive printing processes can 'see' transitions and discontinuities that may be invisible to the naked eye. 
> 
> I ran into this problem immediately with PDN. I was trying to create a palladium printing profile using the PDN approach, and the by-the-book PDN workflow determined a green color to be the best UV blocking color for this printing process. However, when I moved onto the next step, I found that the Epson driver had discontinuities when I printed a density step wedge. The 80% color blocked more UV light than the 100% color! And neither allowed me to print in palladium without the use of restrainers, which has a deleterious effect on print quality.
> 
> Plus the green color gave me grainy highlights, since it dithered with a mix of a high UV blocking ink (yellow) and a low UV blocking ink (cyan).
> 
> That is when I ran across Ron Reeder's book and bit the bullet and started creating negatives with QTR. The learning curve is certainly steeper, and this is primarily because there is no 'one right way'. It is entirely possible for two people using the same printers to come up with entirely different ink profiles that both work fine. 
> 
> But this flexibility is QTR's key advantage. It allows you to do silly things like create profiles with 130% ink loads to get maximum UV light blockage for high DR processes like salt or albumen. It allows you to look at the relative blocking ability of different inks and avoid creating profiles that put dots of low UV blocking inks right next to dots of high UV blocking inks. QTR allows you to pump ink into the highlight areas of photogravure positives so that you get beautifully smooth highlight tones in this printing process (hint: LLK limit 100 at density of 1% gray).
> 
> In short, Roy's QTR driver and Ron's adaptation of the driver for digital negatives allows you complete control over the process and the ability to wring every bit of digital negative 'performance' from your Epson printer. But it comes with the cost of having to learn and understand both how QTR works and how it interacts with your printing method.
> 
> If you are interested in using QTR for making negatives, send Roy your money and buy Ron's book. Read the tutorial on my website outlining how I use QTR. Scour the web and forums for information. It is truly worth your time.
> 
> That said, if you don't want to, or can't invest the time, and are looking for the slickest approach to creating digital negatives with the least amount of hassle and are willing to accept some of the limitations (legal and technical), PDN is certainly a fine approach. Mark has put a great deal of thought and time into creating this system.
> 
> Clay
> 
> --- In QuadtoneRIP@yahoogroups.com, "stormbytes" <stormbytes@...> wrote:
> >
> > Alan,
> > 
> > Interesting that you point it out. I guess I'm not the only one annoyed with Mark Nelson's extensive (and fairly greedy) patent scheme. No one else (pick your author) seems to place such hurdles in the way of teaching creativity.
> > 
> > I'm a big fan of Ron Reeder. I've purchased his recent book on making digital negatives for platinum/palladium printing (which he noted would work well for silver gelatin too!) and emailed him with questions on a number of occasions. He's a great guy!
> > 
> > While I'm just starting out experimenting with QTR and Ron's method, I've come across enough material to be optimistic. 
> > 
> > 
> > 
> > --- In QuadtoneRIP@yahoogroups.com, Alan Vlach <alanvlach@> wrote:
> > >
> > > Check out Ron Reeder's site. He has a procedure for making negatives with QTR. I use QTR and Mark Nelson's Curve Calculator software to execute the steps and calculate the curves. PDN itself is based on the use of color (and no black inks) to create smooth tonalities in the digital negative. I have used it extensively and it is an excellent method to make negatives, but is patented ( you can't teach it without permission which he only gives to university professors or use it for profit without paying a commission) , and, since I teach workshops in making negatives I have switched to using QTR. Ron Reeder's method mixes all the inks when making a negative and I feel the results are as good as PDN. The only downside is that PDN is very stepwise and straightforward during the calibration process whereas there is a lot of testing and guesswork to determine the right ink mix using QTR when mixing all the inks. 
> > > 
> > > Hope this helps
> > > 
> > > Alan
> > > 
> > > 
> > > On Dec 26, 2011, at 3:22 PM, mysteriousmirage wrote:
> > > 
> > > > Hello,
> > > > 
> > > > Has anyone had expereince using the Mark Nelson Precision Digital Negative system with QTR? If so, what has been your expereince? 
> > > > 
> > > > Thanks,
> > > > 
> > > > -Ted
> > > > 
> > > > 
> > > 
> > > 
> > > 
> > > [Non-text portions of this message have been removed]
> > >
> >
> 
> 



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