Printing Pro Photo

[William Walker]

Hi,

I printed these three images on a Canon iFP 8400, one in 16-bit Pro Photo, 1 in 16-bit Adobe RGB (1998) and one in sRGB on Hahnemühle Natural Bamboo.

In every aspect the Pro Photo is better than the other two except with the last two balls where both Adobe and sRGB are much, much better!

I then printed the same again on a Satin paper and the problem disappeared - so, obviously the paper is a factor.

Can anyone explain why in this dark blue/black area, on matte paper, Pro Photo was so much worse than the two smaller colour spaces?

The three samples were taken with my cellphone but the problem is clear! 

Thanks,
William.

[kers]

Gradients are the most difficult thing to print with a dot -printer the inkjet is. printing perfect balls is rare i find.
need more information...
The color profile is of major influence in the outcome. Sometimes you need an other profile to do certain things better.
a different outcome on a satin paper may be because of the larger gamut of colours satin paper can show in print.

Did you print in the relative colormetric modus? Then all colours are printed according to the real color values except for the colors the printer cannot reproduce... So is it a prophoto target? Then it is possible the printer has to make many decisions where to place the unprintable colours.
Most inkjet printer have a gamut of about Adobe RGB on the best paper; Bamboo is a matte Paper with a much smaller gamut.

attached the color spectrum af a glossy white paper ( HM baryta FB) and inside the much smaller HM Bamboo spectrum.. on a Canon 6300 printer

and the second is Adobe RGB with inside HM baryte FB; Adobe RGB can be shown almost entirely by some wide gamut monitors
As you can see the printer can produce darkblue values on Baryte FB that are outside the Adobe RGB spectrum.

the gamut of HM Bamboo will swim inside the prophoto colorspace that is much larger than adobe RGB

[digitaldog]

Short answer: it's the output profile as seen here:

Not all ICC profiles are created equally

In this 23 minute video, I'll cover:
The basic anatomy of ICC Profiles
Why there are differences in profile quality and color rendering
How to evaluate an ICC output profile
Examples of good and not so good canned profiles and custom profiles on actual printed output.

High resolution: http://digitaldog.net/files/Not_All_Profiles_are_created_equally.mp4
Low resolution (YouTube): https://www.youtube.com/watch?v=TNdR_tIFMME&feature=youtu.be

[Doug Gray]

Can anyone explain why in this dark blue/black area, on matte paper, Pro Photo was so much worse than the two smaller colour spaces?

The blue ball in question has only imaginary colors. ProPhoto RGB (0,0,N) where N is any value is always an imaginary color. And even the maximum "blue,'  RGB(0,0,255) has an L* value very close to zero. So how a profile converts that to a print depends on how the profile software maker decides to map imaginary colors to the printer's gamut surface. If they chose to emphasize and retain Lightness and adjust the saturation to the gamut's edge, the result is a maximally black ball.

It appears blue in the monitor only because the conversion math to the monitor's colorspace clips a very negative "blue" after conversion to zero. This results in a display L* pushed up from 0 to around 30 for RGB(0,0,255).

This thread goes into the weeds with the history of Bill Atkinson's Balls. Turns out Bill designed his balls to be printed directly in the printer's colorspace*. Essentially he intended that all the balls would be printed along varous surfaces on the outside of the printer's gamut.

https://forum.luminous-landscape.com/index.php?topic=117752.0

*Thanks to DigitalDog's correspondence with Bill Atkinson to get the historical skinny.

[William Walker]

Thank you Andrew and Doug! The other threads are also great - I should have looked there first!

Regards,

William