QTR-Quadtone RIP

I've been going for high Dmax using the standard Epson inks for the R800 / R1800 on Luster papers like Epson Ultra Premium Luster.  I measured 2.53 on the QTR Calibration Ink Separation page 100% on the Photo Black (PK).  Visually I can't tell the difference after 60% on the PK step wedge.

So I set my PK ink at 90% and did a Black Boost at 100, printed out a Chart Throb Step Chart and used my scanner to Linearize and put the Photoshop Adjustment curve (ACV) in the Curve section of the Gray TAB..  Made some prints that look great.

I thought if I used 60% PK (Density=2.05) and 70% Black Boost what would the prints look like?  I re-did the Chart Throb and Linearized and printed out the same files all at the same 2880, uni-directional, and adaptive hybird.  One is hard pressed to tell the difference in the prints between the two PK ink Limits.

So my question is what good is the extra Dmax we seem to be striving for if you can't see it in a print?  What am I missing?

Terry

Hi Terry-

In photographic terms, DMax is affected most pronounced by flare.  Luster is not a glossy paper and thus will exhibit flare, which lowers the perceived Dmax.  The paper itself may be capable of more when measured with a dedicated instrument- but in your typical viewing environment with multiple light sources converging and reflecting you may not sense it.

Unfortunately a quick google search didn't show what I was hoping to link to.

Your glossy papers will have the richest blacks because flare is limited t non-direct lights- ie, you can light the paper with a point source and eliminate all the other scattering- so the blacker the black the more you can sense it. 

A matte paper will have the least amount of dmax because it is designed specifically to scatter light, so that black gets some 'additional' light that leaks into it and makes it look less dark.

I hope this helps and I haven't been too confusing.

Jason
--- In QuadtoneRIP@yahoogroups.com, "Terry" <TerryGls@...> wrote:

>
> I've been going for high Dmax using the standard Epson inks for the R800 / R1800 on Luster papers like Epson Ultra Premium Luster.  I measured 2.53 on the QTR Calibration Ink Separation page 100% on the Photo Black (PK).  Visually I can't tell the difference after 60% on the PK step wedge.
> 
> So I set my PK ink at 90% and did a Black Boost at 100, printed out a Chart Throb Step Chart and used my scanner to Linearize and put the Photoshop Adjustment curve (ACV) in the Curve section of the Gray TAB..  Made some prints that look great.
> 
> I thought if I used 60% PK (Density=2.05) and 70% Black Boost what would the prints look like?  I re-did the Chart Throb and Linearized and printed out the same files all at the same 2880, uni-directional, and adaptive hybird.  One is hard pressed to tell the difference in the prints between the two PK ink Limits.
> 
> So my question is what good is the extra Dmax we seem to be striving for if you can't see it in a print?  What am I missing?
> 
> Terry
>