The rise of specifications such as ISO 12647 has meant that brands are increasingly seeking accurate colour controls to ensure their images are presented correctly across all their markets and media. At the same time, the evolution of the print process, with the rise of digital and wide-format printing, makes controlling colour output more complex, while the skill and experience of the operators may be lower than the old hands in litho.
All this points to the need for colour measurement and management tools that are easy to use and affordable. This is where the SAI Sprint scanning spectrophotometer comes in, according to Bob Leslie, the managing director of Centurfax, the UK firm that developed it.
We saw a need for something very quick and easy-to-use for people who aren’t skilled in the black art of colour, says Leslie. The Sprint was developed with the view that there would be an explosion of need coming from digital, wide-format and other new markets.
His firm already had the Sprint on the drawing board when it got involved with US wide-format specialist SAI two years ago, and the requirements of the wide-format market, in particular for an easy-to-use device, seemed an ideal first application for the Sprint.
In a sign and display graphics firm, the typical staff turnover for machine operators is something like four months, so an easy-to-use device makes a lot of sense, says Leslie.
Nifty hardware
That ease of use comes from a combination of the nifty Sprint hardware and SAI’s wizard-driven ICC profile creation package Snap. The basic Snap package can create ICC profiles (including CMYK) handles spot-colour measurement and UCR/GCR control. The more sophisticated Snap Pro adds profile editing and the ability to profile six-colour machines too. SAI also sells a second package called Color Excel, which verifies colour accuracy and works with the Sprint and other spectrophotometers.
The software can create master files that specify the colour space and the delta E tolerances of individual colours. These can then be distributed to remote sites to check output is within agreed tolerances. The resulting log files can be imported into a database or spreadsheet for quality tracking and management.
The Sprint builds on Centurfax’s heritage in engineering clever tools to make printers’ lives easier and it is not the company’s first process control tool. A decade ago, when CTP was in its infancy and the absence of film made measuring dots on the plate more important, it came up with a solution called the CCDot. The CCDot took developments in LED illumination and CCDs – the light sensitive chips at the heart of digital cameras – to come up with a new way of accurately measuring dot value on a plate. The rights to the CCDot were eventually sold to colour-management giant X-Rite.
Welcome alternative
This time the Sprint is an alternative to X-Rite’s devices, in particular its i1, and may be welcomed with open arms following that firm’s consolidation of the colour-management market, which has left so few alternative suppliers.
Like CCDot, at the heart of the Sprint is the latest in LED illumination and a light-sensitive sensor, but this time a holographic diffraction grating has been added to the mix, which enables it to make spectrophotometric readings along with software to interpret the results to produce a hand-held scanning spectrophotometer. One detail for the really colour-savvy to consider is that although the current version is effectively a UV-cut device – the light source doesn’t produce UV to excite the optical brighteners used in some stocks – for those that require it, UV illumination is on the list of PrintWeek’s upcoming features.
The Sprint differs from other devices by reading up to 12 patches across the width of its reading area, which means it can make short shrift of a huge number of patches. Secondly, it takes multiple readings per second. In use, this means as you move the handheld device – which looks like a beefed up PC mouse – it reads the patches in a test strip with no need to pause for each patch.
While rival devices such as the X-Rite i1 can do that, Leslie says what sets the Sprint apart is that it will make multiple readings per patch. The software is clever enough to identify whether readings are from the same patch or a different colour. If it is the same patch, it averages the readings. While averaging readings is process control good practice, it is particularly significant for wide-format inkjet where the results can be grainy and noisy, which means a single measurement from a small area may not create accurate enough readings for either process control or profile making. Another advantage of the Sprint for the wide-format market is that its handheld design means that it can sit on top of any media, regardless of its thickness.
Optimal patch size for the Sprint is 20x3mm, which Leslie says was determined from average hand speed when scanning. It can resolve patches as small as 2x1mm. With the maximum number of 10 patches side-by-side, the Sprint can read 3,600 patches per minute. With the optimal six patches side-by-side this drops to 2,160 readings per minute. You might be questioning why a handheld spectrophotometer for wide-format would need to make such a gargantuan number of readings for profile-making and print-colour verification. This is because the Sprint is designed for use in other market sectors, including checking and profiling colour proofers.
Ultimately, Leslie has set his sights on removing the need to manually read the patches – instead he sees the Sprint’s place as embedded in automatic closed-loop control systems.
We built it knowing we wanted to put it inside proofers and digital presses, and that the place where it would really pay off would be measuring the back edge of the press sheet, he says.
This time the Sprint is an alternative to X-Rite’s devices, in particular its i1, and may be welcomed with open arms following that firm’s consolidation of the colour-management market, which has left so few alternative suppliers.
Like CCDot, at the heart of the Sprint is the latest in LED illumination and a light-sensitive sensor, but this time a holographic diffraction grating has been added to the mix, which enables it to make spectrophotometric readings along with software to interpret the results to produce a hand-held scanning spectrophotometer. One detail for the really colour-savvy to consider is that although the current version is effectively a UV-cut device – the light source doesn’t produce UV to excite the optical brighteners used in some stocks – for those that require it, UV illumination is on the list of PrintWeek’s upcoming features.
The Sprint differs from other devices by reading up to 12 patches across the width of its reading area, which means it can make short shrift of a huge number of patches. Secondly, it takes multiple readings per second. In use, this means as you move the handheld device – which looks like a beefed up PC mouse – it reads the patches in a test strip with no need to pause for each patch.
While rival devices such as the X-Rite i1 can do that, Leslie says what sets the Sprint apart is that it will make multiple readings per patch. The software is clever enough to identify whether readings are from the same patch or a different colour. If it is the same patch, it averages the readings. While averaging readings is process control good practice, it is particularly significant for wide-format inkjet where the results can be grainy and noisy, which means a single measurement from a small area may not create accurate enough readings for either process control or profile making. Another advantage of the Sprint for the wide-format market is that its handheld design means that it can sit on top of any media, regardless of its thickness.
Optimal patch size for the Sprint is 20x3mm, which Leslie says was determined from average hand speed when scanning. It can resolve patches as small as 2x1mm. With the maximum number of 10 patches side-by-side, the Sprint can read 3,600 patches per minute. With the optimal six patches side-by-side this drops to 2,160 readings per minute. You might be questioning why a handheld spectrophotometer for wide-format would need to make such a gargantuan number of readings for profile-making and print-colour verification. This is because the Sprint is designed for use in other market sectors, including checking and profiling colour proofers.
Ultimately, Leslie has set his sights on removing the need to manually read the patches – instead he sees the Sprint’s place as embedded in automatic closed-loop control systems.
We built it knowing we wanted to put it inside proofers and digital presses, and that the place where it would really pay off would be measuring the back edge of the press sheet, he says.
Affordable technology
It’s not a fanciful idea. At Drupa, Xerox showed the iGen4, which is the first digital press to include a built-in spectrophotometer, and has since expanded the concept to the iGen3 and as ACQS (Advanced Colour Quality Suite) to the DocuColor 8/7000 series. Granted, Xerox uses a form of the rival X-Rite i1, but there are plenty of other opportunities out there for the Sprint.
At Drupa, inline measuring technologies were centre stage in the offset world as exemplified by units such as Heidelberg’s Inpress Control. Today these devices add a six-figure sum to each press and may only work with the latest machines. The technology in the Sprint promises the potential to make that much more affordable, and with its low cost, small footprint and ability to read 12 patches crammed into a 40mm-wide area in one go, there are some neat applications it could be used for.
One of the biggest things for the press control guys is getting all the colour patches they need under one ink key, says Leslie.
Discussions are underway about the next applications for the Sprint. To date, it only works with the SAI software and, although there is an SDK, other firms have yet to integrate it into their products. A provisional price for the Sprint alone without the Snap software has been set in the region of £1,600, although Leslie adds that UK prices will be pegged to the dollar, and given the current financial climate, subject to fluctuation. A Mac version is under development, and will be launched soon after the Windows XP one, which will be available in the UK from dealer Ripware in the middle of March for a price of under £2,000 including Snap.
__________________________________
SPECIFICATIONS
Spectral analyser holographic diffraction grating with LED illumination
Spectral range 380-730nm
Measuring function reflection only
Platform Windows XP (Mac version in development)
Measurements CIE Lab, CIE XYZ, density, reflectance spectra
Mini patch size 2x1mm
Scanning speed 2,160 patches per minute (optimal), 3,600 patches per minute (max speed)
Interface USB
Price Sprint with Snap profiling software £2,000
__________________________________
THE ALTERNATIVES
X-RITE i1 XTREME
Since swallowing up its nearest rival GretagMacbeth, X-Rite has dominated the colour measurement market, and the i1 has been hugely successful in professional colour applications with more than 150,000 units installed. Compared to the Sprint, the i1 has the flexibility to measure monitors in addition to printed output, and is available in UV and UV-cut versions. It is also a handheld scanning device, although for firms that need to make masses of measurements, the optional IO scanning table can take out the drudgery for a price. The i1Match software includes a wizard-driven simple interface, although X-Rite suggests that users who need more advanced profile editing tools can add its ProfileMaker package.
Measuring function reflection, CRT and LCD screens
Platform Mac and PC
Price i1 Xtreme: £1,080, IO scanning table: £1,375
Contact X-Rite 01625 871100 www.xrite.com
BARBIERI SPECTRO LFP2
Described as the Rolls Royce of spectrophotometers – although given its Italian roots maybe it’s more the Maserati Quattroporte – this XY scanning table offers automation and includes a larger 6mm measuring aperture to minimise the effects of noisy, grainy wide-format output when making profiles. The Spectro LFP2’s USP is its ability to measure and make transmissive materials, notably back-lit films. With its wide-format focus it is specially designed to measure heavy, thick and awkward substrates, including textiles, vinyls, glass, backlit film, stone, ceramics, plastic and even wood up to 20mm thick.
Measuring function reflection and transmission
Platform Mac and PC
Price £5,460
No comments:
Post a Comment