We compare the color gamuts of the three photo printing technologies. %

April 11, 2019

The announcement by Fujifilm US at the IPIC conference in Las Vegas last month of a new silver halide paper with (rather vague) claims of a wider color gamut prompted us to ask iPhoto, the leading independent supplier of photographic paper, how different photo printing technologies compare in terms of color gamut performance.

Their response included the table below, showing how Kodak’s premium photo paper, Endura (Fujfilm does not offer its premium AgX papers in Australia), compares to Epson Surelab inkjet printing and the Indigo digital press:
We then asked a few questions and received the following responses, with this caveat from iPhoto’s Managing Director, Stuart Holmes: “Naturally these are only our opinions, but they are based on a combined knowledge base in the photographic industry for over 200 years, so I would say they would be among the best available on the subject in Australia, if not internationally”:

Interior Imaging: Is there a possibility to improve the current color gamut of AgX paperor is it as good as it gets?
iPhoto Technical Managers: AgX research and development probably peaked many years ago. With the overall decline in production of photographic prints following declining consumer demand, new dry lab technologies have provided a more “sustainable” system for high quality photographic printing. Additional R&D to improve AgX wet lab printing would simply not be viable in today’s environment of reduced economies of scale, especially with the rising costs associated with sourcing raw chemicals for the manufacture of dangerous goods (DG) liquid photochemistry required for light processing. sensitive wetland.

These DG chemicals are also regulated in some global markets due to environmental concerns surrounding the shipping, storage and distribution of hazardous chemicals, increasing the costs of an already declining technology.

At the same time, large format printers and drylab minilab equipment are relatively inexpensive compared to complex wetlab minilab equipment, at around one-third of the installation cost. In fact, compared to the initial setup costs of, say, a Fuji Frontier Digital Wetlab about 15 years ago at over $240,000, today’s dry lab technology could be fully equipped for less $40,000! And the quality of the output will arguably match and exceed traditional AgX in many ways. Its ability to do so at a fraction of the cost of hardware and at similar consumable rates is why print professionals choose new Drylab technology over older Wetlab AgX hardware.

For these reasons alone, it would be hard to imagine any additional investment in AgX R&D being considered economically viable in the future.

The relatively wide color gamut of Indigo printing might surprise some readers – by the chart, it appears to perform better than AgX – any comments on how this relates to “real world” printing?
iPhoto: The gamut graph doesn’t tell the whole story: it’s a measurement of the gamut at the midpoint of brightness only. Other factors influence the appearance of the print. The Indigo has a relatively wide range at this point, but can fall off more at low or high brightness values. The contrast may also be lower. This would explain why Indigo prints lack ‘pop’.

Many screen display devices are now capable of “soft display” of a much wider gamut (coupled with a high contrast ratio). Apple has adopted the wide-gamut “Display-P3” standard for iPhones and computers: more information at https://appleinsider.com/articles/16/09/09/apples-wide-color-screen-on -the-iphone-7-will-lead-to-more-accurate-color-reproduction

Android followed suit: https://en.wikipedia.org/wiki/DCI-P3

Display-P3 and AdobeRGB have a similar gamut and are significantly wider than sRGB, which was the default standard color space until now. Customers today expect prints to have the same vibrant colors they see on their smartphone and tablet screens today.

The Epson Surelab D700 and D3000 inkjet printers have a gamut that closely matches the AdobeRGB/Dispay-P3 color spaces. Silver halide has a gamut closer to the sRGB color space. As you will notice, AgX is particularly limited in the red zone, while AdobeRGB and P3 extend well into the red zone.

Which of the three printing technologies do you think has the most potential for improvement?
Investing to further develop AgX technology is somewhat risky given the shrinking user base and rapid development of inkjet and other dry technologies. It’s kind of like why fewer companies want to invest in coal-fired power plants — they can see that new, more environmentally friendly technologies are coming.

What we saw at Kodak R&D in AgX films and papers in the 1990s produced diminishing returns as the technology reached its limits. Inevitably, the focus had to be on reducing costs rather than improving performance, as digital technology began to impact the market. AgX likely reached its limit around the release of digital LED/laser exposure technologies in the late 1990s/early 2000s (replacing optical enlargers in minilabs) and is limited by the capacity of emulsions and products chemicals to produce a wider range and a finer grain.

Thus, it is certainly not AgX that has the most potential for future improvement.

Color Range1
Epson Surelab D3000 inkjet ‘drylabs’ daisy chained together to create a high volume photo printing facility.

The inkjet technology that should have the most potential, given recent advances. Inkjet printhead nanotechnology is still under development, so higher dpi is still possible. We are still seeing breakthroughs in inkjet such as “fixed full-width printing heads” beginning to enter the market. As this technology advances, the quality and reliability will improve to the point of being applied to higher quality imaging applications. The secondary benefit will be a smaller equipment footprint, much higher speed, and fewer moving parts, resulting in improved duty cycles.

On that note, inkjet technology, or more specifically dry minilabs, could still have a potential card up their sleeve if companies like Epson ever choose to add Light Black ink cartridges (L/bk ) or Light, Light Black (L/lbk) to expand and enhance monochrome tonal performance. In the same vein, it is always possible to add even more color cartridges.

There are currently six inks in the Surelab system: cyan, light cyan, magenta, light magenta, yellow and black. The significant improvement in print quality is the addition of Light Cyan ‘LC’ and Light Magenta ‘LM’ inks, which allow for subtle tonal gradations in color and black and white printing. The inclusion of six colors allows the Epson SureLab to rival continuous tone (AgX) print outputs for smooth skin tones without compromising text sharpness. (In fact, the micro piezo head produces droplets as small as 1.5 picoliters for sharper text than is possible with AgX technology.

So why do professional large-format printers work with eight or 10 or more color cartridges if four or six are enough?
iPhoto: Traditional pigment-based inks tend to have a lower gamut than dye-based inks, so more individual color inks are needed to attempt to cover the same or similar color gamut. The latest pigment ink sets for the Epson SureColor P10070 (44-inch) large format printer, for example, include the following 10 colors: Light Grey, Photo Black, Cyan, Vivid Magenta, Yellow, Light Cyan, Vivid Light Magenta, Dark Grey, Matte Black and Grey.

Elaine F. Brim