ICC profiles and what to expect when using them....

[AS1]

I have a basic question about what I should expect when using an ICC profile (Canon Pro-1 printer, various paper).

(In all cases assuming the media is set correctly and the correct profile is set, and monitor is calibrated properly)

I'm printing from Lightroom and am wondering if
1. ....simply applying the correct profile should give me a good print (or maybe I have to adjust overall brightness to compensate for the "too" bright computer screen (120 cd/m2 is what I have calibrated to)..........OR
2....should I have to go to the file in Lightroom and make adjustments based on the soft proofing (increase contrast, deepen the blacks, increase saturation, overall lighten etc) which is actually what I'm currently doing....?

I guess I'm wondering why I have to make these corrections because I'm thinking the ICC profile should be able to know all these adjustments are needed, and make them as part of the profile since it's for that specific paper and printer?

So I suppose I'm asking does a profile only affect "color" or does it also take into account contrast, density, saturation etc?

Thanks, and apologies if I'm opening a giant can of worms here...
Alan.

[Sbarroso]

The icc profile knows indeed how to translate the colors of your picture (as you should see them in a calibrated monitor).

The problem is, not all the possible colors are available in your printer. The color spaces of devices are limited. For example, some vivid greens are less vivid in your printer. Thats because you tell lightroom to print in "perceptual"  or "relative".  These two methods have different approach to print colors that are not available, printing instead a near one or another.

Softproofing  allows you to see these limitations, and adjust the picture as best as possible to deal with them.

Softproofing should be done only in a new virtual "copy" to print, because it's restricted to certain limits (those of the printer, usually with smaller color space than the monitor). The best is to have a copy of your taste without these extra adjustments/limitations, so you can export to other devices without these limitations.

Because most of my pictures are casual, i don't do softproofing. Sometimes i just go there to check what's best, perceptual or relative. Only in few cases I do some extra adjustments. And the best softproofing is actually printing.

Sent from my E5823 using Tapatalk

[mearussi]

A good ICC profile will reflect on your calibrated screen what your image will look like when printed using your printer/paper combination. When you apply the profile and you don't like what you see (too contrasty, wrong colors, etc) then you need to adjust the screen image to your liking before you print it.   

[ColourPhil]

You'll probably find that 120 cd/m is still too bright, making your prints appear too dark.
In which case reduce the brightness level during calibration, perhaps 80-100 cd/m? YMMV.
Phil

[Garnick]

Hi Alan,

I'll go way out on a limb and assume you haven't had a lot of experience in the workings of any particular printer, and therefore, your questions.  I will attempt to answer them as I interpret them.

"1. ....simply applying the correct profile should give me a good print (or maybe I have to adjust overall brightness to compensate for the "too" bright computer screen (120 cd/m2 is what I have calibrated to).....OR"

There are two answers to this question, NO and Yes.  NO to the first part and YES to the second part.  In other words, you do have to make the appropriate adjustments to your image until it looks the way you would like it to appear on a print.  Of course you do also need to have a properly calibrated display, and that also means a display that is capable of being calibrated to the settings that will give you the best results when printed.  I calibrate my NEC PA27... to a "brightness" level of 90 cd/m, which serves me well for the variety of images I print for my customers, as well as my own images.  Anything higher than that would probably push me toward darkening the image, and therefore probably a dark print as well.

I guess my answer to #1 also refers to #2, so from here I'll try to describe what an ICC Printer/Paper Profile actually is, and why it is necessary.  Think of it this way perhaps.  In your vehicle there is a computer, probably more than one.  Those computers make sure that your vehicle is is operating the way it should, according to the specs.  The computer is constantly gathering information from the vehicle and comparing it to the set of information in the specs for that vehicle.  If everything is operating as it should, there would be no problem.  Except for one variable, the driver.  The computer cannot control the driver, and that's why accidents happen.  If you weren't using a proper printer/paper profile you would be overwhelmed with printing "accidents".  And yes, I do love alliteration.   

The ICC Printer/Paper Profile is simply a communication conduit between the computer, the app you are printing from, and the printer.  You can of course choose to let the printer manage the colour, but usually with sub standard results.  A properly profiled printer/paper combination describes a set of variables that the printer will use when printing on that particular paper.  It will try to reproduce what you are seeing on your display, but if you haven't applied the necessary adjustments to the image it will not look as you might expect on the print.  If you have set the correct ICC profile the printer will do its job properly, assuming all nozzles are firing correctly etc.  However, the printer will NOT make any corrections/adjustments that perhaps should have been applied before you clicked the Print Button. 

In short, it's up to you to make sure the all proper adjustments have been applied before printing, and even then there's no guarantee that your first print or test print will be what you want.  It's sometimes a matter of reassessing what you thought you saw on the display, and perhaps finding something you hadn't noticed or corrected initially. 

ICC Printer/Paper profiles are part of the Quality Control/Colour Management system we all have to adhere to in order to achieve expected and consistent results.  I hope that somewhere in my rather confusing answer I have been able to take a bit of the confusion out of your mind about what an ICC profile actually does, and what it cannot do.

Gary                 

 

[Mark D Segal]

An ICC profile characterizes or describes how a printer lays down colour in response to an instruction to print a certain file value. For example, if the printer lays down a LAB value of 4,-3,-2 for L*, a*, b* respectively when the file value it is trying to replicate is 0, 0, 0 (neutral black), the ICC profile notes this behaviour. [L* is for Luminance and a* b* define colours - if you are not familiar with LAB. Much profiling works in LAB.] The profile contains some tables purposed for printing, soft-proofing and different Rendering Intents. It is descriptive. When you go to print, the colour management system (CMS) in the computer uses that information to send properly adjusted data to the printer, so that the printer is essentially "fooled" into reproducing the intended file values. Because there are billions of colours and a profile is made from anything like 100 to 6000 patches depending on how constructed, there is a lot of interpolation happening, and of course a lot of conversion because the printer ends up printing in CMYK, not LAB and not RGB. So just think of the profile as a dictionary that provides information allowing colour values in the image file to be reproduced correctly when interpolated and converted through the CMS to the printer.

The better the quality of the your ICC profile, the more likely it will help produce the luminance, contrast, colours etc. that you expected by looking at the photo on the display, assuming of course that the display is properly calibrated and profiled as well. For each profile you need to maintain the same printer driver settings (especially Media Type) used for creating the profile, otherwise it will not be accurate.

You can't adjust how the printer prints in its native state, but you can adjust how the display image looks, which in turn induces you to adjust the image in your image editing software. Taking into account that display light is transmitted and the light reflected from a print is - well - reflected, the different character of the illumination alters how you perceive the image, the reflected image normally looking duller and having less contrast than the transmitted one. So before you start, you need to adjust your display, through calibration and profiling, to account for that, otherwise you will be continuously disappointed. The most important calibration settings for your display profile are brightness, gamma (essentially contrast ratio), black point, white point. Especially the correct brightness would vary depending on the surrounding light you are working in. The brighter the environment, the higher the brightness setting can be, and the lower the lower. Working in a reasonably dim room (to avoid distraction), a brightness value somewhere in the range of 90 to 110 should be satisfactory, but you need to test this. If you get the display luminance and contrast right, it will give you correct perception and prediction (under softproofing) of brightness and contrast

Softproofing with paper colour and black ink simulation enabled allows you to see on display quite reliably what will emerge from the printer, provided your display calibration/profiling and printer ICC profiling are good.

[pikeys]

You'll probably find that 120 cd/m is still too bright, making your prints appear too dark.
In which case reduce the brightness level during calibration, perhaps 80-100 cd/m? YMMV.
Phil

!20 cd/m2 is too bright.
On my NEC ,23" monitor,I set mine to 80 cd/m2,and my screen always matches my monitor.

MikeS.

[Mark D Segal]

There is no one size fits all with this. As I said above, the appropriate setting depends on the brightness of the environment in which the display is set-up. It's best to experiment with a range of settings and use the one that results in the best screen to print match.

[digitaldog]

You'll probably find that 120 cd/m is still too bright, making your prints appear too dark.

Or perhaps not, depending on the viewing conditions. That setting is WAY too dim for me, based on how I view my prints next to the display:

[AS1]

Thanks all for the helpful replies, and all the detailed info, much appreciated.

As I understand it now, my colors are being "translated" correctly but the only way to compensate for the huge difference in contrast (and saturation) between screen and paper is to compensate by brightening my images, adding in the "lost" contrast and saturation. This is not something an icc profile will take into account, and do in the background for me...?

I suppose another question I now have is if anyone one uses two different monitor calibrations as part of their workflow....one for general editing and web use, and another (dimmer calibration) exclusively for use when making prints.
Almost everything I shoot ends up being used on the web, either a clients web site or I'm delivering images after a job that I know will be used in a web only environment in future. Obviously most people are seeing these images on very bright, contrasty, computer screens so I need to create a file that looks good in that environment...but every now and then I make prints for myself, my printed portfolio, or clients and I wonder if I should just have another calibration for my monitor that I'd switch to for that...?
Obviously I understand that in either case I need to make a duplicate file (Proof copy) for printing as the adjustments seem to be inevitably large and need to be separate from the original file.
And, if I may, one more question...!
Is it ok to be calibrating a monitor down to 90 or 80cd/m? Is there any danger the monitor is not able to calibrate to that low a level of brightness when it's also capable of 150cd/m or more (or I guess my calibrator will tell me if there's a problem, I'm using NEC wide gamut, and Eizo monitors )?
Thanks again,
Alan.

[Garnick]

!20 cd/m2 is too bright.
On my NEC ,23" monitor,I set mine to 80 cd/m2,and my screen always matches my monitor.

MikeS.

"I set mine to 80 cd/m2,and my screen always matches my monitor".  Obviously I'm missing something here.  Of course I know what you mean by Monitor, but what does the word "Screen" refer to in this situation?  Are you referring to a viewing booth, such as the one shown by Andrew above?  Otherwise, Monitor and Screen are indeed the same thing, are they not?

[Garnick]

Or perhaps not, depending on the viewing conditions. That setting is WAY too dim for me, based on how I view my prints next to the display:

Hi Andrew,

I'm curious.  For what purpose do you use the viewing booth?  Obviously you would need a very large booth to accommodate large prints that you might wish to produce.  I assume the main purpose for the booth is to match the printed image to the display as closely as possible.  Is that correct?  Also, what would be the LUX value of the light you are using to illuminate the print in the booth?  Seems to me it must be rather high in order to match a 150cd/m2 calibration.  In that case, wouldn't your prints need to be illuminated with high LUX value lighting as well?  If you sell prints, do you also make sure the buyer has the proper LUX value lighting to accommodate those prints. 

I'm not questioning your procedures here Andrew, just trying to get a grasp on why such a bright viewing booth, which would also seem to necessitate a bright display as well.  Or, is it vice versa?

Gary 

[Doug Gray]

A monitor at 140 cd/m^2 matches most print luminosity illuminated perpendicularly at 500 Lux. (500/Pi) decreased slightly for paper with 89% reflectivity. If you select show paper white you should set the monitor at 160 cd/m^2. The monitor will decrease in brightness slightly to match the print.

500 Lux is what ICC specs for normal viewing of prints.
http://www.color.org/whyd50.xalter


Lots of people, including me, prefer a lower level. I run 100 cd/m^2 with a lower Lux level to match.

[mearussi]

A monitor at 140 cd/m^2 matches most print luminosity illuminated perpendicularly at 500 Lux. (500/Pi) decreased slightly for paper with 89% reflectivity. If you select show paper white you should set the monitor at 160 cd/m^2. The monitor will decrease in brightness slightly to match the print.

500 Lux is what ICC specs for normal viewing of prints.
http://www.color.org/whyd50.xalter



Lots of people, including me, prefer a lower level. I run 100 cd/m^2 with a lower Lux level to match.

If I set my monitor to 140 cd/m2 my eyes would burn out.

[digitaldog]

Hi Andrew,
I'm curious.  For what purpose do you use the viewing booth?

To view prints next to my display 
Those of you driving your displays well under say 130 cd/\m2, you know those panels will natively produce that lower value? Many cannot.

[Alan Goldhammer]

If I set my monitor to 140 cd/m2 my eyes would burn out.

This is why NEC SpectraView allows one to change the monitor profile on the fly.  You can have one profile for general use and the second for photo work.

[digitaldog]

This is why NEC SpectraView allows one to change the monitor profile on the fly.  You can have one profile for general use and the second for photo work.

And newer units support native cd/m^2 as 40! PA241 goes down to ~90cd/m^2 while PA242 achieves ~40cd/m^2 natively.

[AS1]

And newer units support native cd/m^2 as 40! PA241 goes down to ~90cd/m^2 while PA242 achieves ~40cd/m^2 natively.

Andrew, what's the difference...I mean, how do other monitors achieve a low brightness level if it's not "native"?
Thanks,
Alan.

[digitaldog]

The difference is whether the adjustment is made within the panel using those electronics or, using software, a LUT etc.

[Tim Lookingbill]

I wonder if driving some monitors brighter or dimmer affects their color gamut size as measured by the colorimeter and recorded in the resultant ICC matrix profile. I know changing color temp from standard D65/6500K can reduce the gamut size.