True Colours?

Working with photographers and printers I get involved in a lot of discussions about colour.

The first thing I will ask anyone is if they are working with a calibrated and profiled monitor. Many, even some professional photographers, are not. Do you work with raw files, I ask? ‘Oh yes!’ comes the reply. Well, if you work with raw files and do not have a calibrated and profiled screen, you are frankly wasting your time. Every correction you make is based on what you see on your screen. If the screen is wrong, the resulting file will have the wrong colours.

The best way of explaining this is to ask if they have visited a television showroom. If you have, you will know that every screen in the showroom will display different colours – see the photo. It’s Featured imagethe same with monitors – they are all different. Depending on the type of monitor, you will have different controls and settings, but once it is calibrated and profiled you will see a close rendering of the correct colours. If someone else also has a calibrated and profiled monitor they will see almost exactly the same colours. EIZO and NEC are probably the two most commonly used professional monitors. If you cannot afford a top end monitor like these, profiling will still bring you much much closer to the correct colours. Profiling is done to an international standard set by the CIE.

I have on my desk a MacBook Pro (generally considered to produce great colours) and a large monitor. The large monitor is fully profiled and is the one I use for all colour critical work. If I drag an image in Photoshop from the large screen to the MacBook, the colours shift significantly. If I run a slideshow on the MacBook it looks great but the colours are not technically right!

Why does all this matter? Well, it really matters when you start printing. Here we have other factors coming in like the type of printer, the inks and the paper used. But if we also profile these combinations, we can produce prints in two different locations on the same type of printer using the same paper and inks with almost identical colour. We can also get very close colours on different papers or media, only restricted by the available colour gamut of that paper/ink combination. Without using ICC colour profiles this would simply be impossible. Don’t forget for optimal viewing of prints you should use daylight (5000K).

Of course the next question is, do we all see colour in the same way? The vast majority of us do. The colour blind will not and those with synesthesia may not. I remember holding a pink card against a grey filing cabinet and someone with colour blindness saying they were identical, just one was lighter. For colour blindness there is the Ishihara test. For those whose job involves working with colour, you should try the X-Rite Colour Test and hope to achieve a perfect score or close.

http://www.xrite.com/online-color-test-challenge

Recently we had the famous blue and black dress problem. Different people viewing the same image on the same screen saw it in different ways. Some as blue and black and some as gold and white. The image went viral around the world with hundreds of theories. Psychologists who study colour had many views. Our own industry cFeatured imageolour management specialists also had a range of explanations. The image was badly exposed when taken and in unusual lighting which did not help. The original shop dress is blue and black. Personally I see it as blue and black. For me the black areas are somewhat brownish but my perception of the image puts this down to the lighting and my brain reviews the information to conclude that it is black. If we open the file in Photoshop and measure the colours, be it in RGB, CMYK or Lab, the measurements will show the colours to be in the dark and blue parts of the spectrum.

Finally, colour is also important if we are posting images on the web or using them in MS Office programs or similar. Our responsibility is to get the colours as close as possible to the ‘correct’ colour when we post an image or use it in a software. Sadly we cannot control where or how the image is viewed or how it might be printed, but at least we have given the world the chance to view an image in the way that we intend.


Featured imageCharles Henniker-Heaton has over 30 years experience in the imaging industry, first at Durst and then at Fujifilm as a senior manager involved in retail photo, chemicals and since 2006 as European Marketing Manager for large format printing. He joined ChromaLuxe EMEA in 2014 in charge of European Business Development for large format.

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Do I need a RIP? The answer is YES.

Almost every day I receive the following questions: ‘Will a RIP software make your colors brighter and improve your image quality?’ – ‘Is it really necessary to run your printer with a RIP?’ – ‘Can’t you achieve the same results simply by using the included print driver?’ … “Do I need a RIP?”

wasatchWHAT IS A RIP?
RIP stands for Raster Image Processor. A RIP program is similar to the print driver included with your printer, but with much more control and features. A RIP is designed to handle many files, file types and file sizes without limiting your print capabilities. A RIP efficiently processes your files faster and more consistently, resulting in faster print times and less waiting.

‘Have you ever tried to print 20 large format images (100 x 150 cm) with a file size more than 300 MB at once ? ‘

Through the standard print driver, this can be stressful and time consuming. With a RIP you will have the capability of processing and printing multiple files simultaneously and you will be able to store all of the processed data (the files that you’ve printed), making reprints a breeze. Having this capability will greatly improve printing production and efficiency. A RIP software will give you complete control over handling your files including: scaling, rotating, color correction, color profiling to a wide array of media types, multiple copies, nesting, and much more. Have you ever wanted to maximize the use of your paper roll? do you want to cut back on waste? Do you want to print 250 copies of the same image (in a nice grid) at the same time? The nesting function allows you to combine many different files in one print job.

‘Let’s do the calculation: try to make 250 copies of a 20 x 30 cm image in Photoshop on a canvas that is 111 cm (42″) width with a gap of 1 cm. Indeed, this is time consuming in Photoshop … A RIP can do this in 5 seconds. And if you are unable to do that in Photoshop, then calculate the amount of time it needs to print this big file that contains the 250 copies.’

NEED FOR ACCURACY ?
In addition to above handy functionalities, there are some more important factors to start using a RIP, because a RIP does 3 important things:

1. it can linearise your printer(s):
This means, if you ask to print 50% of cyan, the printer will put the exact amount of ink on the paper, so it will give you 50% of cyan on the Chromaluxe panel. Because the sublimation paper is only an intermediate phase of the total workflow, the printer needs to know how much ink he needs to print that 50% of cyan.
LINEARISE2. it can handle the total amount of ink:
This means, if you print for example a dark grey background, it will use 95% Cyan + 95% Magenta + 95% Yellow + 95% Black. That’s a total of 380% ink on your paper. This will be too much ink for the paper and you will have a pooling-effect. You’ve got the same effect when you drop too much water on a sheet of paper. LINEARISE2A RIP will be able to reduce the total amount of ink (from 380% to 340% for example) without reducing the total amount of colors (also known as color gamut). This makes that you will not have a ‘wet’ output (certainly when you print a lot, or big pictures on the full width of your printer).

3. Color Management is more accurate:
Photoshop or other graphical applications do render (calculate) their colors in 8-bit mode. RIP software, like Wasatch SoftRIP, calculates every color in 16-bit mode. This means 4 times more data to calculate all colors, certainly for the difficult colours like skintones, solid greys or gradients. Do the test: print the below image on your current system (click on the image to download the files). If you see anything other than a perfectly smooth gradient, you need to use a RIP solution.

sixteenBitChallenge


stevieSteven Roesbeke has a huge experience in the graphical industry with a lot of expertise in color management and output solutions. Since 2013 he is the Technical Support Field Engineer at Universal Woods EMEA. Read his technical blog posts to discover helpful tips & tricks and learn more about the do’s and dont’s of (large format) sublimation. You can always contact him at stevenr@chromaluxe.com