Looking at the P700

[maximilian59]

Does anybody know how the Dmax is calculated by x-rite, or is this another of the thousand secrets of this sorftware? Is it to absolute whit? How can it than be calculated with a known paper white?

 

[Keith Cooper]

OK. I still would like to know how Keith got multi-color bronzing when printing a B&W image.

Is Keith's P700's multicolor bronzing effects due to the paper used, the PK/LK/LLK inks only, or does the P700 use multiple colors when printing B&W besides PK/LK/LLK?

It uses some colours.

The effect is distinctly different to what I've thought of as 'bronzing' over the years. The clue for me is the range of colours, which look like interference colours from very thin layers. It looks very much like the effect you'll get heating a sheet of steel from underneath at just one place, where the oxide layer is thin enough to produce interference colours, which vary with thickness.

I've used the P700 since and studiously avoid the higher quality settings - they offer no benefit that I can see, some downside, and take longer. They give some extra numbers for marketing purposes but that's not what I'm interested in in making prints ;-)

 

[palombian]

Does anybody know how the Dmax is calculated by x-rite, or is this another of the thousand secrets of this sorftware? Is it to absolute whit? How can it than be calculated with a known paper white?

As I understood Dmax is not used so much anymore. It can be derived from L (L=0 is the blackest black).

I measure the Lab values of the black patch of a test print with my Colormunki (so I won't argue on 0,5 E-value, not visible with the eye).
As a confirmation when I see that one black is deeper than another.
In general it gives more pop to my prints.

 

[Keith Cooper]

Does anybody know how the Dmax is calculated by x-rite, or is this another of the thousand secrets of this sorftware? Is it to absolute whit? How can it than be calculated with a known paper white?

The density values are the usual standards, (status T etc)
https://xritephoto.com/documents/literature/en/L7-093_Understand_Dens_en.pdf

Of course just how useful Dmax values are for most people printing their images is a vastly different matter ;-)

 

[palombian]

...

I've used the P700 since and studiously avoid the higher quality settings - they offer no benefit that I can see, some downside, and take longer. They give some extra numbers for marketing purposes but that's not what I'm interested in in making prints ;-)

Interesting observation.
As I understand high quality doesn't change anything to the colors, only a tiny bit more details seen with a magnifying glass.

 

[Keith Cooper]

Interesting observation.
As I understand high quality doesn't change anything to the colors, only a tiny bit more details seen with a magnifying glass.

Indeed, I realised a while ago that people who actually buy prints don't get the magnifying glass out.

I think it's also important to go through the range of 'quality' settings with a new printer and see what actual differences there are, as opposed to any that marketing might 'suggest' ;-)
Personally, the word 'Dmax' appearing anywhere is always a potential warning sign...

 

[Ink stained Fingers]

Does anybody know how the Dmax is calculated by x-rite, or is this another of the thousand secrets of this sorftware?

I have seen some different log-formulas over time but luckily not as many variations as there are for the sRGB color space

https://ninedegreesbelow.com/photography/srgb-profile-comparison.html

, Dmax is dating back to the analogue and wet photolab days and yes - I don't really like it either, it is just complicating matters.

Personally, the word 'Dmax' appearing anywhere is always a potential warning sign...

Yes, I only can support that opinion - Epson is using it in their advertising, but it is not as spectacular really as they claim. And the next question is whether you actually can see it. yes - if you print a patch with L=1.2 and one with L=2.3 and hold them side by side in bright light and you want to see a difference in the blacks - you can actually observe it. But as soon as you print a typical image with a few % of a real black RGB=0 you don't see it at all. It might be of interest for B/W prints with a larger black content.

 

[Ink stained Fingers]

You don't need Piezography black inks anymore to reach L levels of 2 or below as per above tests

https://piezography.com/piezography-pro#dmax

 

[Ink stained Fingers]

Does anybody know how the Dmax is calculated by x-rite, or is this another of the thousand secrets of this sorftware? Is it to absolute whit? How can it than be calculated with a known paper white?

How about this one, you would need to recalculate RGB or Lab values to XYZ values, Bruce Lindbloom offers lots of formulas and spreadsheets

http://www.brucelindbloom.com/index.html

Use the 'calc' or 'Math' buttons


'With argyll use spotread. Read the paper white note the Y in XYZ (Yw), then read a printed black patch and note the Y (Yb), then Dmax is -log10(Yb/Yw). Using a Colormunki my Hahnemuhle Photo Rag Pearl sample in front of me yielded -log10(0.348/93.067) = 2.43 '

Found here in posting # 18 at the bottom

https://forum.luminous-landscape.com/index.php?topic=44327

 

[Ink stained Fingers]

I'm just showing in my above table the luminance levels L* of the black patches of the various ink/paper combinations w/o and with a GO overprint.
I have supplemented the table here with the complete Lab values to adddress another aspect - the color - the tint of these black patches - how neutral are these black inks actually

_____________Sihl/Aldi______Netbit/Aldi____HP Premium Plus

Epson P700_____5,25/---______7,80/ 9,23_____ 8,28/ 7,02 L
Photoblack____-0,19/---_____-0,47/-1,00_____-0,54/-1,23 a
______________-2,06/---_____-3,30/-1,11_____-3,15/-0,85 b


Epson P800_____2,69/---______3,80/ 6,23______4,27/ 3,65 L
Photoblack____-0,21/---_____-0,20/-0,51_____-0,35/-0,42 a
______________-0,78/---_____-1,18/-2,06_____-0,96/-0,07 b


Canon PFI105___2,28/---______8,79/ 5,51______6,92/ 4,82 L
Photoblack____-0,09/---_____-0,91/-1,08_____-0,83/-0,63 a
(Pro10s)______-1,38/---_____-5,51/-3,70_____-5,06/-2,63 b

You can see that the b value -b into the green direction - varies between -5.5 and -0,07 for the various ink and paper combinations - with or w/o GO. Not all of that is visible as a tint but the prints with a b=-5.5 or -5 look slightly cooler than the other black patches in direct comparison. This just applies to the pure black patches - I'm not measuring and comparing gray patches here or with other printers, printers with light gray inks and a ABW mode may deliver rather different results, probably interesting but I don't have such printers and inks available.